THE DEVELOPMENT OF MASTERY MOTIVATION IN YOUNG CHIL DREN By Jung Ah Lee A DISSERTATION Submitted to Michigan State University in partial fulfillment of the requirements for the degree of Human Development and Family Studies Š Doctor of Ph ilosophy 2014 ABSTRACT THE DEVELOPMENT OF MASTERY MOTIVATION IN YOUNG CHI LDREN By Jung Ah Lee This dissertation presents two studies exploring th e development of mastery motivation in the child™s first six years of life. Study 1 exa mines potential sources of variation in children™s levels of mastery motivation in the first three yea rs. Study 2 focused on the role of mastery motivation in children™s subsequent development, es pecially executive function skills in the first grade. Study 1 revealed that early maternal depressive sy mptoms affected child™s later mastery motivation and related domains including self-regul ation and general cognitive skills. However, direct negative effect of early maternal depressive symptoms on children™s later mastery motivation was not significant when considering mat ernal parenting at 24 months. In particular, maternal sensitivity mediated the effects of early maternal depressive symptoms on child™s later mastery motivation. The results of chapter 2 also s howed that boys were more vulnerable to the effects of maternal depression. Boys whose mothers had more early depressive symptoms displayed poor general cognitive skills at 36 month s. However, boys™ mastery motivation and self-regulation were not predicted by early materna l depressive symptoms directly but that was mediated by maternal sensitivity. In chapter 3, mastery motivation played the unique role in the development of executive function skills. Children™s mastery motivation at 5 4 months predicted the development of a set of executive function skills including short- and long -term memory abilities and problem-solving skills in the first grade. However, mastery motivat ion did not mediate the effects of children™s early emotional regulation abilities and maternal s ensitivity on later executive function skills. Instead, mastery motivation predicted three of the executive function skills, while emotion regulation predicted another one. This finding conf irmed that mastery motivation and emotional regulation are separate constructs, each with a uni que role in the development of executive function skills. This dissertation extends our current knowledge abo ut children™s mastery motivation. Mastery motivation is influenced by positive matern al behaviors rather than negative behaviors and there are no gender differences in the effects of early maternal depression on later mastery motivation. In addition, mastery motivation improve s children™s later executive function skills and plays a different role from emotion regulation ability in fostering of children™s executive function skills. It implies that mastery motivation is a separate and unique construct. These two studies contribute to understanding more clearly th e relations between mastery motivation and maternal behavior and the mechanism by which childr en™s mastery motivation affects their cognitive outcomes. ACKNOWLEDGEMENTS I am deeply grateful to my advisors, Dr. Claire Val lotton and Dr. Kathy Stansbury. I would never have been able to finish my dissertatio n without Dr. Claire Vallotton™s guidance and persistent help. Dr. Kathy Stansbury as my ‚academi c mom™ has always supported and encouraged me throughout my doctoral program. I wou ld also like to thank all my other committee members, Drs. Holly Brophy-Herb, Deborah Johnson, Cary Roseth, and Marjorie Beeghly for their insightful suggestions and positi ve comments. I want to send my special thanks to the late Dr. Tom Luster who has been my role mod el as a scholar and showed me the passion for people and research. I wish to thank my husband, Wooyeong and son, Micah . They always show me their great love and understand and support me even thoug h they should have spent many important moments without me until I finished my program and dissertation. I appreciate their support and patience. I also appreciate my parents and parents- in-law for their continuous prayer. I want to thank friends who prayed and supported for me whene ver I was frustrated and had some troubles and barriers. Additional gratitude is offered to me mbers of PCCPJ who encouraged me to find out my dream and vision. I would also like to thank Jim and Susan Vogt who are my American family. Without their support and help, I would nev er have been able to complete my program. Finally, but most importantly, thank God. You made my way and I believe you will lead my future, too. TABLE OF CONTENTS LIST OF TABLES .................................... ................................................... ................................. vii LIST OF FIGURES ................................... ................................................... ............................... viii Chapter 1. Introduction ........................... ................................................... ..................................... 1 REFERENCES ........................................ ................................................... ............................. 8 Chapter 2. The Path from Maternal Depression to Mas tery Motivation: The First Three Years . 11 Development of Mastery Motivation ................. ................................................... ................ 12 Development of Self-Regulation .................... ................................................... .................... 15 The Relationship between Maternal Parenting and Chi ldren™s Social and Cognitive Skills 17 The Relationship between Maternal Depression and Ch ildren™s Social and Cognitive Skills .................................................. ................................................... .......................................... 20 The Relationship between Maternal Depression and Ma ternal Parenting ............................ 23 Maternal Parenting Behavior as a Mediator or Modera tor ............................................... ..... 26 Current Study ..................................... ................................................... ................................. 27 Method ............................................ ................................................... .................................... 28 Participants Measures Maternal depression Maternal sensitivity Maternal intrusiveness Mastery Motivation Self-regulation General cognitive skills Data-analytic strategy Results ........................................... ................................................... ..................................... 36 Preliminary Analyses Direct and Mediated Effects of Maternal Depression on Child Outcomes Gender differences in the partial mediation model Moderated effects model Discussion ........................................ ................................................... ................................... 46 Gender Differences Limitations and Future Directions Conclusions REFERENCES ........................................ ................................................... ........................... 52 Chapter 3. The role of mastery motivation in the de velopment of executive function skills ....... 59 The Development of Mastery Motivation ............. ................................................... ............. 59 The Role of Mastery Motivation in Executive Functio n ................................................. ...... 63 Mastery Motivation as a Mediator................... ................................................... ................... 66 Current Study ..................................... ................................................... ................................. 67 Method ............................................ ................................................... .................................... 68 Participants Measures Maternal sensitivity Emotional regulation Mastery motivation Executive function skills Data-analytic strategy Results ........................................... ................................................... ..................................... 75 Preliminary Analyses Path Analysis Direct Path Model Mediated Models Discussion ........................................ ................................................... ................................... 82 Maternal Sensitivity Children™s Emotional Regulation Relating the Child™s Mastery Motivation to Developm ent of Executive Function Skills Limitations Conclusion REFERENCES ........................................ ................................................... ........................... 89 Chapter 4. Conclusions ............................ ................................................... .................................. 94 REFERENCES ........................................ ................................................... ......................... 101 LIST OF TABLES Table 1. Maternal Demographic Characteristics Table 2. Descriptive Statistics for the Main Study Variables Table 3. Bivariate Pearson Correlations among Main Variables Table 4. Comparing Means between Boys and Girls Table 5. Descriptive Statistics for the Main Study Variables Table 6. Bivariate Pearson Correlations among Main Variables LIST OF FIGURES Figure 1. Conceptual Model for Study 1 Figure 2. Conceptual Model for Study 2 Figure 3. Conceptual model of hypothesized relation ships among maternal depressive symptoms and parenting behaviors in early childhood, and chi ldren™s mastery motivation, self- regulation, and cognitive skills Figure 4. The direct path model including standardi zed path estimates. This model shows the direct effects of early maternal depressive symptom s on later social and cognitive skills. Figure 5. The mediational model including standardi zed path estimates. This model shows how maternal behaviors affect the relations between ear ly maternal depressive symptoms and child™s later social and cognitive skills. Figure 6. Fit of the boys™ hypothesized model inclu ding standardized path estimates. This model shows that how maternal behaviors mediates the rela tions between early maternal depressive symptoms and child™s later social and co gnitive skills for boys. The darker lines indicate relationships identified for boys that wer e not identified for girls. Figure 7. Fit of the girls™ hypothesized model incl uding standardized path estimates. This model shows that how maternal behaviors mediates the rela tions between early maternal depressive symptoms and child™s later social and co gnitive skills for girls. Figure 8. The Conceptual Model Figure 9. The Direct Path Model. This model shows t he direct effects of early maternal sensitivity and child emotional regulation and thei r interaction on later children™s executive function skills. Figure 10. The Partial Mediated Model. This model s hows how children™s mastery motivation affects the relations of predictors (i.e., early ma ternal sensitivity, children™s emotional regulation and their interaction) to children™s exe cutive function skills. Figure 11. Boys' Conceptual Model. The darker lines indicate relationships identified for boys that were not identified for girls. Figure 12. Girls' Conceptual Model Chapter 1. Introduction Motivation to achieve a goal and learn new skills i s an important characteristic for child development. This motivation is called mastery moti vation which is defined as an intrinsic force that drives an individual to attempt to master mode rately challenging tasks (Barrett, Morgan, & Maslin-Cole, 1993). Mastery motivation plays a key role in several domains of a child™s development. First, many studies have found associa tions between a child™s mastery motivation and cognitive development. For example, infants™ ma stery motivation at 6 and 14 months has been found to be directly associated with cognitive development at 14 months (Banerjee & Tamis-LeMonda, 2007). For both preschool and young elementary-school aged children, mastery motivation predicts cognitive performance a nd academic achievement (Broussard & Garrison, 2004; Deater Deckard, Petrill, Thompson, & DeThorne, 2005). Secondly, mastery motivation has an influence on children™s social de velopment, and low mastery motivation is associated with behavioral problems (Deater-Deckard , Petrill, & Thompson, 2007; Zhou et al., 2007). Zhou and colleagues (2007) measured children ™s mastery motivation and externalizing problems over five years and showed a significant r elationship in which children with high and stable persistence in puzzle tasks (one of indicato rs of mastery motivation) across the five years were more likely to display low externalizing probl ems across the same time span. Given the importance of mastery motivation to both cognitive and social skills, it is important to understand sources of variation in the development of mastery motivation, and to further delineate its effects on children™s development. This dissertation investigated mastery motivation i n young children (from six months old through the first grade) using longitudinal data de rived from the National Institute of Child Health and Human Development (NICHD) Study of Early Child Care and Youth Development (SECCYD) and consisted of two studies. Study 1 (cha pter 2) allowed me to investigate potential sources of variation in children™s levels of master y motivation in the first three years. Study 2 (chapter 3) focused on the role of mastery motivati on in children™s subsequent development, especially executive function skills in the first g rade. Study 1 (chapter 2), titled The Path from Maternal Depression to Mastery Motivation: The First Three Years, examined possible associatio ns among mastery motivation, early maternal depression, and maternal behavior in the f irst three years of the child™s life. Maternal depression is known to be one of the risk factors a ssociated with many aspects of child development, including physiological, emotional, co gnitive, and social development (Field, 1995; Goodman & Tully, 2006). In particular, Bagner and colleagues (2010) emphasized the critical effects of maternal depression on later ch ild development when it occurs during the first year Œ the sensitive period when the child™s emotio nal regulation and cognitive abilities that are associated with mastery motivation are rapidly deve loping. Maternal depression affects mothers™ abilities to care for and respond to their children . Mothers who report more depressive symptoms are likely to show more controlling or withdrawn be haviors, more negative affect, less affectionate touch, and spend less time playing wit h their infants (Field, 2010). Importantly, research has shown that maternal behavior that is a ssociated with depression - intrusiveness or insensitivity - has a negative impact on children™s mastery motivation (Banerjee & Tamis- LeMonda, 2007; Frodi, Bridges, & Grolnick, 1985; Lu tkenhaus, 1984; Spangler, 1989; Yarrow, Morgan, Jennings, Harmon, & Gaiter, 1982). Although many studies have shown that child mastery motivation is an important characteristic f or children in order to interact with and adjust to their environment effectively, the research that has examined how maternal depression affects mastery motivation in young children is limited. In addition, there is very little known about the interaction of maternal depression, maternal behavi or, and mastery motivation, especially at an early age. Study 1 investigated whether early mater nal depressive symptoms would affect children™s later mastery motivation and related dom ains (i.e., self-regulation and general cognitive skills). Specifically, I expected that ea rly maternal depressive symptoms would predict children™s mastery motivation and related domains a t 36 months. Previous research has shown that the quality of maternal behavior (i.e., intrus iveness, sensitivity, and responsiveness) mediated the effects of maternal depression on chil dren™s development such as behavior problems, language development, and self-regulation (Leckman-Westin et al.,2009; Feldman et al., 2009;Stein, Malmberg, Sylva, Barnes, & Leach, 2008 We know that depression predicts intrusiveness, which in turn decreases mastery moti vation, but no study has examined intrusiveness as a mediator between maternal depres sion and mastery motivation. Study 1 examined how the quality of maternal behavior at 24 months (i.e., sensitivity and intrusiveness) impacted the relations between early maternal depre ssion and children™s later mastery motivation (36 months) and related domains (i.e., self-regulat ion and general cognitive skills). Self- regulation and general cognitive skills are associa ted with academic achievement (Broussard & Garrison, 2004; (Calkins, 2007; Valiente, Lemery-Ch alfant, Swanson, & Reiser, 2008), and self- regulation and mastery motivation are intertwined s kills (Wang & Barrett, 2013). However, these skills may be differentially influenced by maternal behaviors and maternal depression. Thus, self-regulation and general cognitive skills were i ncluded in the model in order to compare the effects of maternal factors on mastery motivation, self-regulation, and general cognitive skills. The results of study 1 has the potential to provide evidence that mastery motivation is in fact a separate construct with different predictors and ef fects than self-regulation and general cognitive skills. Figure 1 shows the conceptual model for Stu dy 1. Figure 1. Conceptual Model for Study 1 Following on the examination of the early precursor s to mastery motivation (Study 1), Study 2 (chapter 3) allowed me to test the role of mastery motivation in children™s development from 36 months to the first grade, focusing on the development of executive functions that are considered to be important capacities related to ch ildren™s social-emotional development and academic achievement. Executive function is defined as a set of higher order cognitive processes which are associated with abilities to control thou ght and action (Seguin & Zelazo, 2005). Both mastery motivation and executive function are neces sary for a child™s goal-directed behavior. Further, both are related to self-regulation, thus their mechanisms may be correlated to each other. However, little research has studied their a ssociations. Children with higher levels of mastery motivation tend to persist in conducting ch allenging tasks. During such tasks, children can practice their existing knowledge and skills an d have opportunities to acquire new information that could apply to future problem solv ing (Wang & Barrett, 2013). Thus, in this study, I hypothesized that mastery motivation would promote the development of executive function skills. I also expected that the child™s level of mastery m otivation would mediate the relations between executive function skills and earlier predi ctors of mastery motivation, such as maternal behavior and child emotional regulation. Previous r esearch has shown that children™s executive function skills are promoted by characteristics of maternal behavior such as maternal sensitivity as well as behaviors that support the child™s auton omy (Bernier, Carlson, & Whipple, 2010). Children™s emotional regulatory abilities are also expected to influence their executive function skills. For example, children with higher levels of emotional regulation display better working memory and inhibitory control abilities in cognitiv ely challenging tasks (Blankson et al., 2013; Calkins & Dedmon, 2000). Mastery motivation may imp act these relations. However, little research has examined the interactions of these ski lls, particularly in relationship to the development of executive function. Task persistence is a key instrumental indicator of mastery motivation. In order for children to persist in a d ifficult task, they must manage the frustration or fear that may be elicited during the task. Some chi ldren may give up because of this negative emotion, while other children may keep at their tas ks to achieve a goal by controlling their negative emotion. Therefore, the control of negativ e emotion is thought to facilitate children™s persistence in tasks, which in turn provide childre n with more opportunities to learn new skills and knowledge and achieve their goals. Sensitive an d supportive maternal behavior encourages children to initiate their own actions to achieve g oals and to continue to engage in them. In particular, maternal behavior such as respecting th e child™s perspective, goals, and choices, and encouraging the child™s active role in tasks improv e children™s motivation to achieve goals, which in turn helps children try out their current skills and eventually obtain age-appropriate problem-solving skills that involve executive compo nents (Bernier et al., 2010). Thus, it may be possible that a child™s mastery motivation mediates the relationship between maternal behavior and the development of the child™s executive functi on skills. No study has specifically examined the mediating role of mastery motivation among exec utive function skills and their precursors: maternal behavior and child™s emotion regulation. S tudy 2 examined these questions more directly and contributed to our understanding of th e role of mastery motivation in development of executive function skills. Specifically, I expec ted that maternal behavior (i.e., sensitivity and autonomy supporting behavior) and children™s emotio nal regulation at 36 months would affect children™s executive functions skills in the first grade directly, and also would affect executive function indirectly via children™s mastery motivati on at 54 months. Figure 2 shows the conceptual model for the study 2. Figure 2. Conceptual Model for Study 2 This dissertation is organized as follows. In Chapt er 2, Study 1 is described in more detail as a complete scholarly paper. It includes a review of previous research on the relations between early maternal depressive symptoms and later master y motivation and related domain such as self-regulation and school readiness. In addition, the role of maternal behavior as a possible mediator in the relations of early maternal depress ive symptoms to later mastery motivation and related domains is examined. Similarly, Chapter 3 e xplains Study 2 in more detail as a complete scholarly paper. Previous research on development o f executive function skills and their predictors, especially maternal behavior and the ch ild™s emotion regulation, is reviewed. In addition, the possible role of the child™s mastery motivation in mediating the relationship between executive function skills and their predict ors is examined. Because Chapters 2 and 3 are written as separate papers, intended for individual submission and publication, the methods that are common across both studies (e.g. dataset, data collection, variables) are described in each chapter. Finally, in Chapter 4, I summarize these t wo studies, and discuss future research directions. REFERENCES REFERENCES Bagner, D. M., Pettit, J. W., Lewinsohn, P. M., & S eeley, J. R. (2010). Effect of maternal depression on child behavior: a sensitive period? Journal of the American Academy of Child & Adolescent Psychiatry, 49 (7), 699-707. Banerjee, P. N., & Tamis-LeMonda, C. S. (2007). Inf ants' persistence and mothers' teaching as predictors of toddlers' cognitive development. Infant Behavior and Development, 30 (3), 479-491. Barrett, K. C., Morgan, G. A., & Maslin-Cole, C. (1 993). Three studies on the development of mastery motivation in infancy and toddlerhood. In D . J. Messer (Ed.), Mastery motivation in early childhood: Development, measurement and so cial processes (pp. 83Œ108). London: Routledge. Bernier, A., Carlson, S. M., & Whipple, N. (2010). From external regulation to self-regulation: Early parenting precursors of young children's exec utive functioning. Child Development, 81 (1), 326-339. Blankson, A. N., O'Brien, M., Leerkes, E. M., Marco vitch, S., Calkins, S. D., & Weaver, J. M. (2013). Developmental dynamics of emotion and cogni tion processes in preschoolers. Child Development, 84 (1), 346-360. Broussard, S. C., & Garrison, M. E. B. (2004). The relationship between classroom motivation and academic achievement in elementary-school-aged children. Family and Consumer Sciences Research Journal, 33 (2), 106-120. Calkins, S. D., & Dedmon, S. E. (2000). Physiologic al and behavioral regulation in two-year-old children with aggressive/destructive behavior probl ems. Journal of Abnormal Child Psychology, 28 (2), 103-118. Deater Deckard, K., Petrill, S. A., Thompson, L. A. , & DeThorne, L. S. (2005). A cross sectional behavioral genetic analysis of task persistence in the transition to middle childhood. Developmental Science, 8 (3), F21-F26. Field, T. (1995). Infants of depressed mothers. Infant Behavior & Development, 18 , 1-13. Frodi, A., Bridges, L., & Grolnick, W. (1985). Corr elates of mastery-related behavior: A short- term longitudinal study of infants in their second year. Child Development, 56 (5), 1291- 1298. Goodman, S., & Tully, E. (2006). Depression in Wome n Who Are Mothers: An Integrative Model of Risk for the Development of Psychopatholog y in Their Sons and Daughters. In C. L. M. Keyes & S. H. Goodman (Eds.), A handbook for the social, behavioral, and biomedical sciences (pp. 241-280). New York, NY: Cambridge University Press. Lutkenhaus, P. (1984). Pleasure derived from master y in three-year olds: Its function for persistence and the influence of maternal behavior. International Journal of Behavioral Development, 7 (3), 343-358. Spangler, G. (1989). Toddlers' everyday experiences as related to preceding mental and emotional disposition and their relationship to sub sequent mental and motivational development: A short-term longitudinal study. International Journal of Behavioral Development, 12 (3), 285-303. Wang, J., & Barrett, K. C. (2013). Mastery motivati on and self-regulation during early childhood. In K. C. Barrett, N. A. Fox, G. A. Morgan & L. A. D aunhauer (Eds.), Handbook of Self- Regulatory Processes in Development: New Directions and International Perspectives (pp. 337). New York: Psychology Press. Yarrow, L. J., Morgan, G. A., Jennings, K. D., Harm on, R. J., & Gaiter, J. L. (1982). Infants' persistence at tasks: Relationships to cognitive fu nctioning and early experience*. Infant Behavior and Development, 5 (2-4), 131-141. Zhou, Q., Hofer, C., Eisenberg, N., Reiser, M., Spi nrad, T. L., & Fabes, R. A. (2007). The Developmental Trajectories of Attention Focusing, A ttentional and Behavioral Persistence, and Externalizing Problems during Scho ol Age Years. Developmental Psychology, 43 (2), 369. Chapter 2. The Path from Maternal Depression to Mas tery Motivation: The First Three Years Mastery motivation Œ motivation to achieve goals Œ is an important characteristic, supporting multiple domains of child development. F or example, mastery motivation promotes better cognitive performance and academic achieveme nt, and is associated with fewer behavior problems (Broussard & Garrison, 2004; Deater-Deckar d, Petrill, Thompson, & DeThorne, 2005; Turner & Johnson, 2003; Zhou et al., 2007). However , the association between mastery motivation, self-regulation, and general cognitive skills call into question whether mastery motivation is actually a unique concept, separate f rom these other well-established characteristics. Further, mastery motivation is affected by parental behaviors including sensitivity and intrusiveness (Banerjee & Tamis-LeMonda, 2007; Yarr ow, Morgan, Jennings, Harmon, & Gaiter, 1982); these same behaviors are important predictor s of children™s self-regulation and cognitive skills (Dodici, Draper, & Peterson, 2003;Moilanes, Shaw, Dishion, Gardner, & Wilson, 2010). However, we know very little about effects of mater nal depression on child™s mastery motivation even though maternal depression is known to be one of the risk factors associated with many aspects of child development including greater beha vioral problems and lower academic performance (Goodman, 2007), as well as an influenc e on the maternal behaviors which support the development of mastery motivation (Banerjee & T amis-LeMonda, 2007). Mastery motivation, self-regulation, and general co gnitive skills are each associated with academic achievement (Broussard & Garrison, 2004; C alkins, 2007; Valiente, Lemery-Chalfant, Swanson, & Reiser, 2008). In particular, mastery mo tivation and self-regulation can be seen as intertwined skills (Wang & Barrett, 2013). However, they may be differentially influenced by maternal behaviors and maternal depression. For exa mple, one previous study showed that mastery motivation is affected by positive maternal behaviors rather than negative behaviors (Kelley, Brownell, & Campbell 2000), while another study reported that self-regul ation is influenced more by maternal negative behaviors (Kar reman, Van Tuijl, Van Aken, & Dekovic, 2006). Limited research has examined the effects of maternal factors on mastery motivation, self-regulation, and general cognitive skills toget her. Comparing the effects of maternal factors on these three sets of skills could help elucidate whether mastery motivation is in fact a separate construct from self-regulation and general cognitiv e skills, with different predictors and outcomes. The main focus of the current study is an examinati on of the possibility that early maternal depression influences the child™s mastery motivation and related domains, including child self-regulation and general cognitive skills. In addition, the current study investigated the role of maternal behavior Œ specifically sensitivit y and intrusiveness - in the association between early maternal depression and children™s later mast ery motivation, self-regulation, and general cognitive skills. The results of this study have th e potential to elucidate sources of variation in the development of mastery motivation. Development of Mastery Motivation In the current paper, the term fimastery motivationfl refers to the child™s motivation to persist in challenging tasks, achieve goals, and ma ster skills. Many terms have been used, for the most part interchangeably, for describing the child ™s motivation to achieve goals: mastery motivation, intrinsic motivation, competence motiva tion, and achievement motivation (Messer, 1993). Rothbart and Hwang (2005) have defined motiv ation as fithe energization (instigation, activation) and direction (focus, aim) of behaviorfl (p. 170). According to Barrett and Morgan (1995), mastery motivation is a multifaceted and in trinsic force that drives an individual to make active and independent attempts to interact with th e world in order to master the environment or achieve goals. It includes actions or activities to fiexplore (gain knowledge), influence (cause an auditory or visual display), or control the physica l environmentfl (Jennings, 1993, p. 37). It is important to conceptually distinguish mastery motiv ation from competence; competence refers to an ability to conduct a task properly, while master y motivation involves the motivation that urges an individual to attempt to master the environment or achieve goals. Thus, successful achievement of the goal is not necessarily implied in mastery motivation; the child does not need to be successful with the tasks in order to demonst rate mastery motivation (Barrett, Morgan, & Maslin-Cole, 1993). However, highly motivated child ren are more likely to learn successful strategies than children with low levels of mastery motivation, which fosters children™s competence in problem-solving (Barrett & Morgan, 19 95). Mastery motivation is an internal process that cann ot be observed directly. Thus, mastery motivation has been assessed through individual™s b ehaviors. Barrett and colleagues (1993) suggested that indicators of mastery motivation can be seen as falling into two domains: instrumental and expressive aspects of mastery moti vation. Instrumental aspects of mastery motivation refer to behaviors that are used to achi eve a goal, including the length of time that a child persists or focuses on mastering a new skill or task. Other examples of instrumental aspects of mastery motivation are the child™s need for phys ical and/or cognitive control over his or her environment, and a preference for challenging moder ate or difficult tasks or novelty, children™s agency such as initiative and choices about activit ies, and levels of engagement in tasks (Barrett & Morgan, 1995; Wigfield, Eccles, Schiefele, & Davi s-Lean, 2006). Children who persist in conducting the task for a longer period or choose a difficult task rather than an easy task can be considered highly motivated children. Expressive as pects of mastery motivation refer to task- related emotions expressed by the child during or a fter conducting the task such as pleasure, enthusiasm, interest, or pride (Barrett et al., 199 3). Highly motivated children tend to engage in the task enthusiastically or show more smiles and p ositive expressions during or after the task. Researchers have argued that positive emotions prom ote children™s persistence or engagement in challenging tasks and persistence helps children le arn and master new skills. In the current study, children™s task-persistence and enthusiasm in tasks are used as indicators of instrumental and expressive aspects of mastery motivation respective ly. Behavior and affect relating to mastery motivation can be seen during early development. However, the nature of mastery motivation transform s as the child develops and these changes are affected by changes in cognition (Barett & Morg an, 1995). Barrett, MacTurk, and Morgan (1995) proposed that fimastery motivation is not a s tatic, stable, unitary trait, but rather a complex, malleable, processfl (p. 347). According to Jennings (1993), from birth to about 9 months, infants begin to find and explore novel obj ects with interest and they become aware of contingency produced by their own movements. They s mile and laugh when this contingency occurs. This is consistent with Piaget™s notion tha t the motivation to explore and engage the environment is intrinsic and one of the earliest sc hemas (Miller, 1983). From about 9 to 18 months many infants are able to separate means from ends and act in order to achieve both simple goals and process-oriented goals. For exampl e, when putting blocks in a bucket, the goal of the infant in this period is to put an individua l block into the bucket, rather than trying to fill the bucket, which involves a future goal. Infants s how interest by smiling during this activity. From about 18 months to 3 years, toddlers become in creasingly able to focus on goals, and the end points for their activities focus on outcomes. As in the previous example of block play, toddlers in this period can conceptualize, in a sim ple way, their goal to fill the bucket with the blocks, and will not terminate their activities (pu tting blocks in the bucket) until the bucket is filled. They recognize that their goal is to fill the bucket with blocks rather than just putting blocks in the bucket. The behavior continues becaus e they perceive that all the blocks are not yet in the bucket (Jennings, 1993). Focusing on outcome s allows toddlers to compare their own behavior or situation with the desired outcome so t hat they can evaluate their ongoing behavior. Toddlers may show pride or embarrassment based on t his evaluation of their own success, and these emotional expressions are considered to be in dicators of the evaluative aspect of mastery motivation (Jennings, 1993). After 17 months, child ren™s self-awareness and self-evaluation increase and affect mastery motivation (Barrett & M organ, 1995), which means that parental socialization or other aspects of the environment m ay have a greater influence on mastery motivation beginning in late toddlerhood. Relatedly , at this age, children begin to show individual differences in their interpretation of t heir own performance, in preference for more or less challenging tasks, and in their tendency to pe rsist in a chosen task (Barrett & Morgan, 1995). Even though mastery motivation is intrinsic and ope rate from infancy, changes in the nature of mastery motivation, as indicated by increasing vari ability in degree of motivation, indicate that children are increasingly affected by interactions with parents (Barett & Morgan, 1995; Bush- Rossnagel, Knauf-Jensen, & DesRosiers, 1995). The e ffects of parenting on mastery motivation will be addressed later in more detail. Development of Self-Regulation Self-regulation and mastery motivation are inte rtwined skills. Both mastery motivation and self-regulation are fiumbrella constructs with a num ber of interrelated subsystems that, together, support children™s adaptive functioning with respec t to the nonsocial, social, and self-domainsfl (Wang & Barrett, 2013, p. 338). Self-regulation ref ers to the ability to adjust one™s cognitive, emotional, and social behaviors appropriately to a particular situation (Posner & Rothbart, 2000). In early life, children acquire self-regulation ski lls and strategies, such as the delay of gratification and exerting control over impulses, a ctions, and emotions. This repertoire allows the child to cope with challenges, and promote independ ent, autonomous, and self-initiated action (Calkins, 2007). Children who cannot acquire approp riate self-regulation abilities experience more behavioral problems (Calkins & Fox, 2002) and are reported to have difficulty controlling their negative emotions, forming positive relations with peers, following others™ instructions, and achieving better academic performance (Calkins, 200 7; Valiente et al., 2008). Given this course of development, self-regulation c ould facilitate the development of children™s mastery motivation. Higher self-regulato ry ability could encourage the child to maintain positive engagement in challenging tasks b y giving them the ability to control their negative attention or affect, such as frustration i n response to initial task failures. Chang and Burns (2005) found that children with better self-r egulation skills (attention-shifting and attention-maintaining) exhibited more mastery-orien ted behavior in puzzle tasks. The ability to regulate attention could enable children to focus o n tasks and enable them to gain knowledge related to tasks and appropriate solutions. Accordi ng to Howes and colleagues (2003), children with poor self-regulatory abilities were more easil y distracted from tasks, which would be expected to deprive them, over time, of opportuniti es to learn new skills. Ultimately, poor self- regulatory skills hinder children™s success in scho ol (Valiente, Lemery-Chalfant, Swanson, & Reisner, 2008). By examining whether self-regulatio n predicts mastery motivation in early childhood, this study addresses whether mastery mot ivation is a possible mechanism through which self-regulation affects children™s school suc cess. The Relationship between Maternal Parenting and Chi ldren™s Social and Cognitive Skills According to Vygotsky (1986), children develop thei r social and cognitive functioning through interactions with more knowledgeable partne rs who guide them in learning beyond their current skill level. For very young children, the m other, or primary caregiver, is the most likely partner. Thus, maternal behavior is important in th e development of a wide range of children™s behaviors and skills. Previous research suggests that specific parenting behaviors facilitate or impede the development of mastery motivation. For example, Bau mrind (1971) claimed that children have more opportunities to challenge and succeed in task s when parents support the child™s autonomy with warmth and nurturing. Maternal sensitivity and responsiveness are also associated with the child™s mastery motivation, especially task-persist ence. Spangler (1989) found that the high quality of maternal interaction during free play pr omoted the development of mastery motivation in 24-month-old children. In particular, children w hose mothers showed high responsiveness and involvement were likely to display high persistence . Banerjee and Tamis-LeMonda (2007) showed the importance of maternal behavior at six m onths in the development of child™s mastery motivation. A mothers™ teaching (i.e., maternal sen sitivity, fostering cognitive growth, and fostering social-emotional growth) at 6 months was significantly associated with her infant™s persistence at both 6 months and 14 months. Mothers ™ sensitivity and responsiveness may encourage children to explore, access, and persiste ntly engage in stimulating toys or activities, which in turn allows children to gain more knowledg e and new skills. The idea that securely attached children use their mothers as a secure bas e from which to explore is consistent with this research (Risken-Walraven et al., 1993). Kelley, Br ownell, and Campbell (2000) reported associations between a child™s mastery motivation a nd maternal scaffolding, defined as correcting the child™s behavior with a neutral or p ositive tone and supporting the child™s efforts and autonomy. Kelley and colleagues found that chil dren whose mother used scaffolding were less likely to avoid challenging tasks; that is, ma ternal scaffolding appears to encourage a child to face challenges for the mastery of activities. Contrary to the positive parenting described above, maternal control impedes the development of a child™s mastery motivation. After 17 months of age, the child™s self-awareness and intentionality are developed to the degree that children can select tasks and actions that they can do. If a mother is too directive and takes char ge of the child™s interaction with the environment, doing for the child what he could do f or himself, children may learn to more passively respond to the environment rather than to initiate interactions with it (Busch-Rossnagel et al., 1995). This, in turn, deprives a child of o pportunities to learn and master new knowledge and skills. This is also consistent with the tenets of attachment theory which posits that children develop a sense of self Œ their own characteristics and capacities in the world, and an expectation of how the world responds to them - within their re lationship with their primary caregivers (Bowlby, 1982). Thus, experiencing maternal intrusi veness may cause children to internalize a distrust of self, which in turn, could weaken maste ry motivation. Previous research has provided evidence of the negative effects of maternal intrus iveness on mastery motivation. For example, Lutkenhaus (1984) found that maternal physical inte rruption and critical feedback had negative effects on children™s motivation in 3-year-old chil dren. Yarrow and colleagues (1982) also showed that high levels of maternal control were re lated to decreased mastery motivation in toddlers. These findings indicate that mastery moti vation is reduced when children feel controlled by others. In addition to its associations with mastery motiv ation, maternal behavior is also associated with the child™s cognitive skills. Dodic i, Draper, and Peterson (2003) measured qualities of parent-child interactions including pa rents™ use of age-appropriate language, emotional tone, joint attention, parental guidance, and parental responsiveness when children were 14, 24, and 36 months. Children™s literacy ski lls were assessed at the spring or summer prior to kindergarten entry. They found that higher quality parent-child interactions at 24 and 36 months promoted the development of children™s liter acy skills. In addition, maternal supportiveness and providing a positive learning en vironment are also strong predictors of children™s later language development (Chazan-Cohen et al., 2009). The role of parenting in the development of child self-regulatory ability has also been well studied. A meta-analysis of 41 studies on pare nting and preschoolers™ self-regulation showed that parental control (i.e., harshness, taki ng over an activity, insisting upon parent strategy) was negatively associated with children™s self-regulation, while responsive parenting (i.e., positive affect, acceptance, sensitivity, pr ocess of coordination, or warmth) was unrelated to self-regulation (Karreman, Van Tuijl, Van Aken, & Dekovic, 2006). Specifically, Karrenman and colleagues examined three categories of childre n™s self-regulatory abilities, including compliance, inhibition, and emotion regulation, and examined the effects of different aspects of parent behavior on each of them. Interestingly, on ly child compliance was significantly associated with parents™ controlling behavior. Chil dren™s inhibition and emotion regulation were not related to parental controlling behavior or to sensitive parenting. The researchers argued that there may be no relations between parental responsi veness and child™s self-regulation because most studies used community samples in which there was little variability in parental responsiveness. They also suggested that parental c ontrolling behavior might be less important for internalized self-regulation, such as inhibitor y control and emotion regulation. According to Karreman and colleagues (2006), external monitoring is not needed for internalized self- regulation so inhibitory control or emotion regulat ion may be less influenced by maternal controlling behavior. Recently, Moilanen and collea gues examined the relationships between parenting and initial levels and growth trajectorie s in children™s self-regulation, especially in inhibitory control, between the ages of two and fou r years (Moilanen, Shaw, Dishion, Gardner, & Wilson, 2010). They reported that supportive and involved parenting of 2-year-olds was positively associated with children™s inhibitory co ntrol at the same age, and predicted faster growth in inhibitory control between the ages of 2 and 4 years. Harsh parenting, such as negative verbal, directive, and physical behavior, was assoc iated with lower levels of children™s inhibitory control at two years of age, but did not predict g rowth in inhibitory control ability between the ages of two and four years. These results indicate that positive parenting may have concurrent and long-term effects on children™s self-regulation , while negative parenting may have only concurrent effects. Based on studies reviewed, the effects of parenting behavior on children™s development may be very specific to different domains or skills . Thus, the present study focuses on the separate specific effects of maternal sensitivity v ersus intrusiveness on children™s mastery motivation, self-regulatory ability, and general co gnitive skills. The Relationship between Maternal Depression and Ch ildren™s Social and Cognitive Skills Maternal depression is known to be one risk facto r associated with pathways to many different outcomes in child development. For exampl e, infants of depressed mothers are more likely to have a difficult temperament, less likely to have secure attachments with their mothers, and show lower levels of mental and motor developme nt than children of non-depressed mothers (Goodman & Gotlib, 2002). Children of depressed mot hers show more behavioral problems, negative affect, and poorer academic performance th an children of non-depressed mothers (Goodman, 2007). Feldman and her colleagues (2009) also found that infants of mothers who were diagnosed with major depressive disorder showe d poorer social engagement and higher levels of cortisol reactivity, which indicated poor er physiological regulation. In addition, higher negative emotionality and less mature self-regulato ry behaviors and goal-directed tactics were observed in infants of depressed mothers (Feldman, et al., 2009). The effects of maternal depression on children™s co gnitive development have also been established. Milgrom, Westley, and Gemmill (2004) f ound negative associations between early maternal depression and later cognitive development . Specifically, at the age of 42 months, children of mothers who were diagnosed with a major depressive disorder showed lower IQ scores and lower basic school skills than children of non-depressed mothers. Maternal depression early in the child™s life also has negative effects on children™s language development, an important indicator of school readiness (Janus & Of ford, 2007; Milgrom et al., 2004). For example, Milgrom and colleagues (2004) reported tha t children whose mothers had been diagnosed with postpartum depressive disorder showe d poorer language skills at 42 months. Maternal depression also affects children™s self-re gulatory skills. Marchand, Hock, and Widaman (2002) found that maternal depressive sympt oms had concurrent effects on children™s behavioral regulation abilities, especially externa lizing behaviors at age four. Longitudinal effects of early maternal depression have also been reported. For example, Chazan-Cohen and her colleagues (2009) measured maternal depressive symptoms when children were 14, 24, and 36 months, and at kindergarten entry, and investiga ted the relationship between early maternal depression and children™s self-regulation abilities and related behavior problems at age five. According to their findings, children whose mothers reported more maternal depressive symptoms at 14 months showed more behavior problems at age five. Although there were no significant associations of early maternal depressi ve symptoms (e.g. 14 months) with later children™s emotional regulatory skills, increases i n mothers™ depressive symptoms from 14 months to five years were related to children™s poo rer emotional regulatory skills. Although many researchers have studied the negative effects of maternal depressive symptoms on children™s development, only a few stud ies have examined whether maternal depression affects mastery motivation in infants an d toddlers. In one study, Redding, Harmon, and Morgan (1990) assessed the relationship between maternal depression and infants™ mastery behaviors in 1- and 2-year-olds and their mothers. They found that infants whose mothers reported more depressive symptoms showed lower task competency (ability to put puzzle pieces in the right places) and lower persistence in chall enging tasks at both ages. In addition, children™s task pleasure at two years was negatively associate d with maternal depression. Similarly, Hart and colleagues (1998) found that infants of depress ed mothers spent less time in manipulating and examining a single toy than non-depressed mothe rs. Results of several other studies are consistent with these findings. Jennings and Abrew (2004) showed that 18-month-old toddlers of depressed mothers were less likely to show persiste nce and to display less mastery pleasure indicated by smiling and positive affect in mastery tasks than toddlers of non-depressed mothers. Moreover, toddlers of depressed mothers needed more prompts in order to focus on the tasks and were less likely to express pride. These results su ggest that maternal depression can impede the development of mastery motivation. Despite the relatively consistent findings regardin g the relationship of maternal depression to children™s motivation and skills, the re are still some inconsistencies which may indicate more nuances in these relationships. Kurst jens & Wolke (2001) examined the influence of maternal depression on children™s cognitive deve lopment over a 7-year period. According to their findings, children whose mothers met diagnost ic criteria for a depressive episode were not significantly different in cognitive skills measure d at 20 months, 58 months (4.8 years), and 76 months (6.3 years) from those whose mothers had no depressive symptoms. Similarly, Brennan and colleagues (2000) failed to find any significan t relationships between maternal depressive symptoms (postpartum, 6 months, and 5 years old) an d children™s language skills at age five. Additionally, Murray and colleagues (1996) found no adverse effects of postnatal depression on children™s cognitive functioning at age five. Howev er, they found that children who experienced insensitive parenting early in life showed poorer c ognitive functioning than children with more sensitive parents. This suggests that children™s co gnitive functions may be affected by the quality of early parental interactions rather than directly by early maternal depression per se, or may be explained by interaction between the depressive sym ptoms and specific parenting behaviors. Further, it is also likely that the effects of mate rnal depression may act more directly on some domains of development, while the influence of mate rnal depression on other domains may be attenuated by mediators, specifically in parenting behavior. The Relationship between Maternal Depression and Ma ternal Parenting Maternal depression limits mothers™ abilities to care for and respond to their children. The negative effects of maternal depression on pare nting and mother-child interactions have been well documented (for review, see Sohr-Preston & Scaramella, 2006). For example, mothers who report more depressive symptoms are likely to s how more controlling or withdrawn behaviors toward their children, more negative affe ct, less affectionate touch, and they spend less time reading and playing with their infants (Field, 2010). In addition, depressed mothers have been shown to be less sensitive toward their infant s™ cues (Murray, Fiori-Cowley, Hooper, & Cooper, 1996). Hart and colleagues found that depre ssive mothers tended to be more intrusive during free play with their infants than non-depres sive mothers, and showed more physically intrusive behaviors, particularly to boys (Hart et al., 1998). Recent research has also provided additional evidence that maternal depressive sympto ms are associated with negative emotional and behavioral characteristics of the mother-child relationship. For example, Caughy, Huang, and Lima (2009) found that depressed mothers were o bserved to have higher rates of conflict with their toddlers during a teaching task and were more likely to use criticism, scolding, threatening, and aversive physical control to the c hildren™s oppositional behavior. Based on the evidence reviewed above, one hypothesi s of the current study is that mothers with higher levels of depressive symptoms w ill show less sensitive and more intrusive behaviors toward their children than mothers with l ower levels of maternal depressive symptoms. However, despite the strong evidence of association s between maternal depression and negative parenting behaviors, there are also some inconsiste nt associations between maternal depression and specific parenting behaviors. For example, Cart er and colleagues (2001) did not find any differences in early play interactions or infant at tachment security between groups of depressed mothers (without any other psychopathology) and non -depressed mothers (without any psychopathology). However, mothers who had depressi on and other psychopathology together showed poorer relationships with their infants. The se results suggested that maternal depression may not affect the mother-child relationship direct ly by itself, but accompanied with other psychopathology may have a negative effect on the m other-child relationship. Further, Forman and colleagues (2007) asserted that reducing matern al postpartum depressive symptoms was not sufficient to improve positive parenting to the lev el of non-depressed mothers. They compared maternal responsiveness in depressed and non-depres sed mothers and found that depressed mothers were less responsive to their infants at th e first year than were mothers in the non- depressed group. Even though mothers received treat ment and recovered from depression, they were still observed to have significantly lower lev els of maternal responsiveness than non- depressed mothers. The results indicated that curre nt maternal depression might not sufficiently account for differences in maternal responsiveness. An alternate explanation for these findings is that those who received treatment recovered from cl inical depression, but they may have maintained sub-clinical depressive symptoms which s till affected their interactions with their children. The studies reviewed above suggest that t here may be a more complex relationship between maternal depression and parenting behaviors , rather than a simple direct association. Variations in the relationship between maternal dep ression and parenting may be caused by differences in samples across the studies, in the s everity of maternal depressive symptoms, or may be due to the different effects of maternal dep ression on specific parenting behaviors. For example, maternal intrusive behaviors may be strong ly influenced by characteristics of maternal depression, however, maternal sensitivity or respon siveness may be affected more weakly by maternal depression. Another possible explanation i s that maternal depression may have only short-term effects on maternal sensitivity or respo nsiveness, or may not be linked directly. A meta-analysis by Lovejoy and colleagues (2000) revi ewed 46 observational studies and found that the association between depression and negativ e maternal behavior was strongest, while the relation of depression to positive maternal behavio r was relatively weak. In the current study, we examine whether early maternal depressive symptoms (at 6 months) differentially affect positive (sensitivity) and negative (intrusiveness) maternal parenting when toddlers were 24 months of age. Maternal Parenting Behavior as a Mediator or Modera tor Positive and negative aspects of parenting may play distinct roles in the relationship between early maternal depression and toddlers™ lat er development. Specifically, higher levels of insensitivity and intrusiveness, if present in depr essed women, could be proximal contributors to the achievement of competent levels of self-regulat ion, mastery motivation, and school readiness. Previous research has supported the hypothesis that characteristics of mother-child interactions mediate the association between maternal depression and toddlers™ development. Leckman- Westin and her colleagues (2009) examined the longi tudinal effects of maternal depressive symptoms and mother-toddler interaction patterns du ring the child™s second year on children™s later behavior problems. They found that early mate rnal depressive symptoms were significantly associated with children™s later behavior problems when mothers provided lower levels of responsiveness and more negative affect. At the sam e time, however, maternal positive interaction, such as high levels of responsiveness and positive affect, mitigated the negative effects of depressive symptoms on children™s behavi or problems, as much as 7 to 10 years from the first assessment of maternal depression and chi ld behavior problems (at 2 years of age). These results support the role of maternal behavior s as a moderator in the relation between early maternal depression and children™s later developmen t. Similarly, a recent study showed the moderating effects of maternal sensitivity on the r elationship between maternal depression and infant social behaviors (Feldman et al., 2009); how ever, maternal intrusiveness did not moderate the effects of maternal depression on infants™ beha viors. Another study found that maternal parenting behavior mediated the effects of early ma ternal depression on children™s later language development (Stein, Malmberg, Sylva, Barnes, & Leac h, 2008). In that study, maternal depressive symptoms at child age 10 months, but not 36 months, predicted low quality of maternal parenting (i.e., less maternal responsiven ess and less provision of opportunities for learning), which in turn affected language skills i n children at 36 months. Although previous research has found that maternal behavior mediates or moderates the relationships between maternal depression and various child outcomes, we still know very little about how maternal behavior may alter the relationships between early maternal depression and children™s later mastery motivation. Current Study In the current study, using longitudinal data, we examined whether early maternal depressive symptoms affect children™s later social and cognitive skills (i.e., mastery motivation, self-regulation, and school readiness), and whether this effect is direct or indirect via maternal positive and negative parenting behaviors. Recent r esearch has suggested that early maternal depression is a strong predictor of toddlers™ devel opmental outcomes. For example, Bagner and colleagues (2010) emphasized the crucial effects of maternal depression during the first year on later child development because the first year is a sensitive period when the child™s emotional regulation and cognitive processing abilities Œ whi ch are both associated with mastery motivation Œ develop rapidly. However, mixed results of other studies suggest that these effects are mediated by specific qualities of maternal behavior . Based on these findings, the present study focused on how early maternal depressive symptoms, measured at 6 and 24 months, affect children™s later social and cognitive skills at the beginning of preschool (36 months). I expected early maternal depressive symptoms would be signifi cantly associated with maternal sensitivity and intrusiveness in toddlerhood, and that maternal depressive symptoms would predict children™s regulatory ability, general cognitive sk ills, and mastery motivation at the beginning of preschool. I also tested whether maternal parenting in toddlerhood (i.e., sensitivity and intrusiveness) mediates or moderates the relations of early maternal depressive symptoms with toddlers™ social and cognitive skills at the beginn ing of preschool. Figure 3 provides a conceptual model of the hypothesized relationships. Figure 3. Conceptual model of hypothesized relation ships among maternal depressive symptoms and parenting behaviors in early childhood, and chi ldren™s mastery motivation, self-regulation, and cognitive skills Method Participants The data used in the present study came from the Na tional Institute of Child Health and Human Development (NICHD) Study of Early Child Care and Youth Development (SECCYD). Families with full-term and healthy newborns were r ecruited from designated hospitals at ten locations across the United States: Little Rock, AR ; Irvine, CA; Lawrence, KS; Boston, MA; Philadelphia, PA; Pittsburgh, PA; Charlottesville, VA; Morganton, NC; Seattle, WA; and Madison, WI during January 1991 to November 1991. M others and children participating in this study met the following criteria: (a) the mother wa s over 18 years old, (b) the mother could speak and understand English, (c) the mother did not have any substance-abuse problems, (d) the child was a singleton, (e) the child did not have any dis abilities, and (f) the child was not hospitalized for more than 7 days. Data were collected during ho me visits and in a laboratory playroom. In particular, the Phase I data were collected at 1 mo nth, 6 months, 15 months, 24 months, and 36 months of a child™s age. During the course of the f irst three years of the study some subjects dropped from the study for a variety of reasons suc h as the family moved away, family illness, and so on. Therefore, a total 1,231children (635 bo ys and 596 girls) and their mothers participated in the current study. The mothers™ mea n age when children were 1 month of age was 28.28 years (SD = 5.60). The majority of mothers we re White (N = 1031; 83.8%) and married (N = 993; 77.8 %). In addition, the mean maternal educ ation level was 14.2 years. The mean house hold income at 6 months of child™s age was $49,126 (SD = $40,047). Table 1 shows full maternal demographic characteristics. Table 1. Maternal Demographic Characteristics Maternal Characteristics N Percent Marital status Married 993 77.8 Partnered, cohabitating 108 8.5 Separated 17 1.2 Divorced 2 .2 Widowed 1 .1 Single 147 11.6 Other 8 .6 Education Less than high school 115 9.2 High school diploma 255 20.7 College 409 33.2 Bachelor™s degree 266 21.6 Graduate & professional 186 15.1 Ethnicity American Indian/ Eskimo/Aleut 8 .6 Asian/Pacific Islander 27 2.2 Black/Afro-American 145 11.8 White 1031 83.8 Other 20 1.6 Measures Maternal depression . In order to assess early maternal depressive sympt oms, the Center for Epidemiological Studies Depression Scale was ad ministered to mothers when their infants were 6 and 24 months of age (CES-D;Radloff, 1977). The CES-D is a self-report scale to measure depressive symptoms in non-clinical populat ions. Mothers were asked to rate the frequency of 20 symptoms, during the past week. Res ponses were firarely or none of the time (less than 1 day)fl, fisome or a little of the time ( 1-2days)fl, fioccasionally or a moderate amount of time (3-4 days)fl, and fimost of all of the time ( 5-7 days)fl. Sample items include: I felt I was just as good as other people, I thought my life had been a failure, and I could not get figoingfl. The Cronbach alpha for the scale was .892. The aver age score between the measures at 6 and 24 months was used. Maternal sensitivity . Maternal parenting was assessed by observing mate rnal sensitivity and intrusiveness in mother-child interactions when children were 24 months of age. Maternal sensitivity referred to a mother™s child-centered b ehavior that focused on her child™s needs, moods, interests, and capabilities. Sensitive behav ior requires attention to the child™s cues, as well as correct interpretation of the signals. The sensitive mother uses this awareness to guide her behavior with her child. A semi-structured procedur e, the three boxes episode, was utilized to measure the quality of mother-child interaction dur ing the 24-month lab visit. Three toys (e.g., story book, toddler kitchen, and discovery cottage) were placed in separate boxes and the mother and her child were asked to play with these toys on e at a time for 15 minutes. However, the researcher did not tell the mother that she had to interact with the child, nor how long the child could spend with each toy in order to observe more naturally how sensitive mothers were to their children™s interests and needs, the degree to which mothers were involved with play, and how mothers dealt with the transition from one toy to a nother. Child and maternal behaviors were videotaped during the episode. Trained observers co ded maternal sensitivity from the videotaped three box episode at the end of each 30s interval u sing a four-point rating scale (1 = not at all characteristic, 4=highly characteristic). Ratings w ere summed over intervals and divided by the number of intervals. This qualitative scale was ada pted from the Observation Record of the Caregiving Environment (ORCE) developed for NICHD s tudy (Vandell, 1996) . Sensitive maternal behaviors included acknowledgment of the c hild™s affect, responsiveness to the child™s talk and /or activity, facilitating the child™s pla y, sensing the child™s interests, providing an appropriate level of stimulation and appropriate ra nge or variety of activities, and so on. Two coders received 19-20% of the tapes randomly in ord er to determine inter-coder reliability. Inter- coder reliability was calculated as the intra-class correlation (Winer, 1971), which was .80 for maternal sensitivity. Maternal intrusiveness. In order to assess maternal positive parenting, ma ternal intrusiveness was examined. Maternal intrusiveness indicated adult-centered behaviors rather than child-centered behaviors. The intrusive mother imposes her agenda on her child and does not allow her child an opportunity to respond at hi s/her pace. As with maternal sensitivity, the three box procedure was used to assess maternal int rusiveness at 24 months of age. Maternal behaviors were videotaped and the trained observers coded following maternal intrusive behaviors: offering a continuous barrage of toys, d irections or suggestions, taking away toys or curtailing activities without a reasonable explanat ion while the child still appears interested, not allowing the child to make choices, excessively dis ciplining the child, and so on. As with the assessment of maternal sensitivity, these behaviors were coded in 30s intervals with a four-point scale (1 = not at all characteristic, 4=highly char acteristic), which had been adapted from ORCE (Vandell, 1996). Higher scores indicated higher le vels of intrusive maternal behaviors. Intercoder reliability was determined and calculate d in the same manner as was done for maternal sensitivity. The intraclass correlation fo r maternal intrusiveness was .69. Mastery Motivation . The three box procedure during 36-month lab visit was used to assess the child™s mastery motivation consisting of two measured components: enthusiasm and persistence. Three toys, such as drawing materials with stencil set, dress up clothes and the cash register with 8 pennies, and Duplo Preschool Buildi ng set were placed in separated open boxes. These toys were selected based on several principle s: the toys should be interesting to children in this age group, and were expected to foster a varie ty of activities which meant that children could have different goals for each toy. For example, chi ldren might try to learn how to stencil using toys in the first box or children could explore the operation of the cash register using toys in the second box. As with the three box task at 24 months , mother-child interactions at 36 months were videotaped for 15 minutes. Enthusiasm referred to whether the child acts with vigor, confidence, and eagerness to do the tasks, and invo lves a sense of agency. Enthusiasm ratings were based on goal-oriented behavior on the task wi th a seven-point scale (1 = Very low, 7 = Very high) that was adapted from Egeland and Hieste r™ teaching task rating scale (1993). For example, if child seemed hesitant to engage the tas k or does so mechanically and with no evidence of being interested in or excited by his/h er performance, or the child showed extreme lack of confidence in his/her behavior, coders rate d this behavior as 1. In order to master objects, children need to engage in and manipulate objects. Thus, instrumental aspects of mastery motivation were assessed using children™s persisten ce to indicate the extent to which the child was actually involved with toys in the session. The child™s involvement with toys was coded with a seven-point scale from Very low (1) to Very high (7). The coders rated involvement as 1 if the child did not engage with any of the toys, refused to become involved and either fled or spent his/her time in off-task activities; involvement wa s rated 7 if the child showed sustained attention and active involvement with the toys, and played pe rsistently throughout the session. Intercoder reliability was determined and calculated using the same method described earlier for maternal sensitivity and intrusiveness. The intraclass corre lations were .67 for the child enthusiasm and .66 for the child persistence. Self-regulation . The forbidden toy task was used to assess the chi ld™s level of self- control by measuring their ability to delay and/or inhibit play with an attractive toy. The procedure was conducted at the laboratory playroom at 36 months with the child™s mother present. The child was asked not to touch an attrac tive toy (crocodile toy) that was placed within arm™s reach, until told to do so (150 seconds). Mot hers were also asked not to give any help to their children in order to minimize relationship-co ntext confounds. Self-regulatory ability (self- control) was determined by measuring the length of time the child refrained from touching and playing with the toy after initial instructions fro m the experimenter. Inter-rater agreement for timing latency to touch the toy was .92. General cognitive skills . Braken Basic Concepts Scale (BBCS; Bracken, 1998) w as utilized to measure the child™s general cognitive s kills at 36 months. The BBCS is a full scale diagnostic instrument, along with two screening tes ts. The school readiness component, including the five subscales of the diagnostic scal e, was administered in the current study. The battery consisted of a 10-item Colors test, a 10-it em Letter Identification test, a 14-item Number/Counting test, a 7-item Comparisons test, an d a 20-item Shapes test. Each item was scored either 1 or 0 for pass or fail. Scores on th e five subtests were summed to create the school readiness composite. Subsequently, a School Readine ss standard score, which used for the general cognitive skills in the study, were compute d based on the BBCS standardization data and has a potential range of 1 to 19. The overall mean standard score was 9.02 (SD=3). Data-analytic strategy Structural equation modeling (SEM) with SPSS and AM OS 17.0 was used to test a partial mediation model in which early maternal dep ression was hypothesized to affect children™s later mastery motivation and related domains (gener al cognitive skills and self-regulation) both directly and indirectly via specific types of mater nal parenting (sensitivity and intrusiveness). First, the direct path model was fit in order to as sess the direct associations between early maternal depressive symptoms and children™s later m astery motivation, self-regulation, and general cognitive skills. Second, the partial media tion model (with all paths estimated) tested the direct and indirect effects of early maternal depre ssive symptoms on children™s outcomes via maternal parenting. Third, the direct model and par tial mediation model were compared to determine the best fitting model by examining the d ifferences between model chi-squares. Models were evaluated based on several criteria. Fi rst, the 2 value, as an indicator of overall fit, was assessed comparing the covariances within the hypothesized model and the null model. The probability value related to 2 indicates the likelihood of obtaining a 2 value that exceeds the 2 value when the null model is true. Therefore, a lo w and statistically nonsignificant 2 value represents a good model fit (Schumacker & Lo max, 2010). The comparative fit index (CFI) and root mean square error of approximation ( RMSEA) were also calculated to evaluate models. For a good model fit, CFI should be .95 or above; RMSEA should be .06 or below (Hu & Bentler, 1999). The current study compared two mo dels including the partial mediated and the full mediated models, and the expected cross-valida tion index (ECVI) was calculated. A smaller ECVI value indicates a better model fit with data ( Byrne, 2010). Results Preliminary Analyses The mothers™ and toddlers™ mean scores, standard deviations, and ranges on mai n variables are reported in Table 2. Table 3 shows th e results of correlations among the main variables. As expected, early maternal depressive s ymptoms were significantly correlated with 24-month maternal sensitivity and with 24-month int rusiveness, as well as with toddlers™ self- regulation, general cognitive skills, and mastery m otivation (i.e., enthusiasm and persistence) at 36 months. Early maternal depressive symptoms were positively related to 24-month maternal intrusiveness, and negatively related to maternal s ensitivity and to toddlers™ social and cognitive skills at 36 months . In addition, maternal sensitivity at 24 months was positively linked to child™s social and cognitive skills at 36 months, while mat ernal intrusiveness at 24 months related negatively to child™s social and cognitive skills. The full matrix of correlations is in Table 3. Table 2. Descriptive Statistics for the Main Study Variables Main Variable Mean SD Range Early maternal depression 9.12 7.33 0-46.5 Maternal sensitivity (24M) 3.01 0.75 1-4 Maternal intrusiveness (24M) 1.48 0.73 1-4 Child self-regulation (36M) 92.15 68.72 0-1 51 Child cognitive skills (36M) 9.02 2.90 1-17 Child enthusiasm (36M) 4.97 1.05 1-7 Child persistence (36M) 5.24 1.15 1-7 An independent-samples t-test was conducted to examine gender differences i n the scores of our main variables (i.e., early maternal depress ive symptoms, maternal sensitivity, maternal intrusiveness, children™s self-regulation, general cognitive skills, and mastery motivation). There was not a significant difference in early maternal depressive symptoms between mothers of boys and girls, nor was there a child gender difference in maternal sensitivity at 24 months. However, mothers of boys were more intrusive than mothers of girls at 24 months. Further, consistent with previous research, there were significant gender di fferences for each of the child variables in which girls demonstrated more positive development than did boys (see Table 4). Table 3. Bivariate Pearson Correlations among Main Variables Main Variable 1 2 3 4 5 6 7 1. Early maternal depression - 2. Maternal sensitivity - 0.24 ** - 3. Maternal intrusiveness 0.23 ** - 0.54 ** - 4. Child self-regulation - 0.14 ** 0.20 ** - 0.19 ** - 5. Child cognitive skills - 0.24 ** 0.31 ** - 0.26 ** 0.28 ** - 6. Child enthusiasm - 0.09 ** 0.22 ** - 0.16 ** 0.16 ** 0.25 ** - 7. Child persistence - 0.12 ** 0.18 ** - 0.14 ** 0.18 ** 0.25 ** 0.56 ** - * p < 0.05, ** p < 0.01 Table 4. Comparing Means between Boys and Girls Variable Boys Girls t-value M SD M SD Early maternal depression 8.95 7.50 9.30 7.15 -0.7 9 Maternal sensitivity (24M) 2.97 0.73 3.05 0.76 -1.8 7 Maternal intrusiveness (24M) 1.58 0.78 1.38 0.64 4.74 *** Self-regulation (36M) 82.39 69.83 102.44 66.08 -4 .88 *** General cognitive skills (36M) 8.57 2.87 9.5 2.84 -5.53 *** Enthusiasm(36M) 4.80 1.10 5.16 0.96 -5.83 *** Persistence (36M) 5.03 1.19 5.46 1.06 -6.40 *** *** p < 0.001 Direct and Mediated Effects of Maternal Depression on Child Outcomes In order to analyze the mediational effects, direct path model and indirect path model need to be tested and the relationship of predictor and outcomes must decrease substantially when a mediator is in the model (Little, Card, Bova ird, Preacher, & Crandall, 2007). Maternal education and family income were included in the mo del as controls. Figure 4 shows the direct path model from early maternal depressive symptoms to children™s later social and cognitive skills. The direct path model fit the data well ( 2[4] = 1.58, ns , CFI = 1.00, RMSEA= 0.00, ECVI= 0.052). Early maternal depressive symptoms we re associated with children™s later social and cognitive skills including self-regulatory, gen eral cognitive skills, and mastery motivation, in the predicted direction. Next, the partial meditati onal model was tested to investigate whether maternal sensitivity and intrusiveness mediated the relationship between early maternal depressive symptoms and later children™s social and cognitive skills at the end of the toddler period. The partial meditation model is summarized in Figure 5. Consistent with the hypothesis, the model fit the data ( 2[6] = 3.69, ns , CFI = 1.00; RMSEA= 0.00, ECVI= 0.08). Children whose mothers had higher levels of early depressive symptoms showed poor self-regulation and lower levels of general cognitive skills at 36 mont hs, but early maternal depressive symptoms did not predict children™s mastery motivation. Moth ers with higher levels of early depressive symptoms were less sensitive and more intrusive wit h their children at 24 months. In addition, children™s social and cognitive skills were predict ed by maternal sensitivity at 24 months. On the other hand, maternal intrusiveness predicted self-r egulation and general cognitive skills, but not mastery motivation at 36 months. Comparing the hypothesized model (partial mediation model) with the direct path model using chi-square difference test, the results showe d that there was no significant difference between them. Next, we calculated the effect size f or each pathway. Maternal sensitivity and intrusiveness at 24 months mediated 30% of the rela tion between early maternal depressive symptoms and later self-regulatory ability, 30% of the relation between early maternal depressive symptoms and general cognitive skills, a nd 48% of the relation between early maternal depressive symptoms and later mastery moti vation. Therefore, the partial mediation model was considered to be a better explanation of the associations of early maternal depressive symptoms with children™s later social and cognitive skills than the direct path model. Figure 4. The direct path model including standardi zed path estimates. This model shows the direct eff ects of early maternal depressive symptoms on later social and cognitive s kills. *** p < 0.001, ** p < 0.01, * p < 0 .05 Figure 5. The mediational model including standardi zed path estimates. This model shows how maternal b ehaviors affect the relations between early maternal depressive symptoms and chil d™s later social and cognitive skills. *** p < 0.001, ** p < 0.01, * p < 0 .05 Gender differences in the partial mediation model The preliminary test showed that girls outperformed boys in social and cognitive skills at 36 months so the hypothesized model was retested to ex amine whether early maternal depressive symptoms would affect boys and girls differently. F igure 6 shows the mediational model for boys ( 2[12] = 11.43, ns; CFI = 1.00; RMSEA = .01). Early maternal depressive symptoms directly predicted only boys™ later general cogniti ve skills, but not mastery motivation or self- regulation. In this model, early maternal depressiv e symptoms predicted maternal sensitivity and intrusiveness at 24 months, and maternal sensitivit y at 24 months affected all later outcomes for boys, mediating the effects of early maternal depre ssive symptoms on later outcomes. Mastery motivation was predicted by maternal education leve ls. The girls™ model had different significant paths th an that of the boys™ (see Figure 7, 2[12] = 11.43, ns; CFI = 1.00; RMSEA = .01). As exp ected, early maternal depressive symptoms predicted maternal sensitivity and intrusi veness at 24 months. However, early maternal depressive symptoms did not directly predi ct any of the later outcomes. Girls whose mothers were more sensitive at 24 months showed bet ter mastery motivation and general cognitive skills at 36 months. Interestingly, mater nal sensitivity did not predict girls™ later self- regulation. In addition, mastery motivation was not affected by the demographic risks - maternal education or family income - for girls, though it w as for boys. Figure 6. Fit of the boys™ hypothesized model inclu ding standardized path estimates. This model shows that how maternal behaviors mediates the relations between early maternal depre ssive symptoms and child™s later social and cogniti ve skills for boys. The darker lines indicate relationships identified for boys th at were not identified for girls. *** p < 0.001, * p < 0.05 Figure 7. Fit of the girls™ hypothesized model incl uding standardized path estimates. This model shows that how maternal behaviors mediates the relations between early maternal depre ssive symptoms and child™s later social and cogniti ve skills for girls. *** p < 0 .001, * p < 0.05 Moderated effects model Finally, interaction effects of early maternal depr essive symptoms and maternal parenting (i.e., sensitivity and intrusiveness) were examined . The interactions of early maternal depressive symptoms with maternal sensitivity and maternal int rusiveness were calculated and were added to the model as predictors of children™s outcomes, in addition to their main effects. This moderated effects model demonstrated a poor fit wit h the data ( 2 [14] = 1394.92, p < 0.001, CFI = 0.82; RMSEA= 0.28). Thus the best fitting models remain the mediational models, with separate models for boys and girls. Discussion In the current study, using a large and diverse sam ple of mothers and their toddlers, we examined the impact of early maternal depressive sy mptoms on children™s later social and cognitive skills, and asked whether maternal sensit ivity and intrusiveness mediated or moderated these relationships. Using a longitudinal design, w e examined the mechanism by which early maternal depressive symptoms affect later child fun ctioning during the first three years of a child™s life. Consistent with the results of previous research ( Feldman et al., 2009; S. Goodman & Tully, 2006), results of the current study indicate d that maternal depressive symptoms were negatively associated with children™s later social and cognitive skills. In particular, children whose mothers had more early depressive symptoms sh owed poorer self-regulation skills and lower levels of general cognitive skills. Even thou gh the direct path model showed that early maternal depressive symptoms predicted children™s l ater mastery motivation, the relations between them did not remain significant when matern al sensitivity and intrusiveness at 24 months were included in the model. This finding sug gests that the negative effects of early maternal depressive symptoms on children™s later ma stery motivation were fully mediated via maternal parenting, specifically maternal sensitivi ty, but not maternal intrusive behavior, during toddlerhood. These findings build on previous rese arch (Jennings & Abrew, 2004; Redding et al., 1990) which identified direct effects of mater nal depression on aspects of children™s mastery motivation such as task persistence and task pleasu re, but had not examined possible mediators of this relationship. Further these previous studie s examined the relations between concurrent maternal depression and children™s mastery motivati on, while the current research assessed how early maternal depressive symptoms influenced later children™s mastery motivation. The lack of a significant direct effect of early maternal depre ssive symptoms on later mastery motivation indicated that mastery motivation may be more vulne rable to concurrent maternal depression than early maternal depression. The results of the current study showed that matern al sensitivity, but not maternal intrusiveness, affected the relations between early maternal depressive symptoms and later mastery motivation. The specific associations betwe en positive versus negative parenting behaviors and children™s mastery motivation is cons istent with the findings of Kelley and colleagues™ (2000) in which maternal sensitivity an d scaffolding at 24 months promoted child mastery motivation at 36 months, but maternal intru sive control was not associated with it. Maternal intrusive behavior may have only concurren t effects. Graziano, Calkins, and Keane (2011) examined maternal parenting and children™s s ustained attention which is associated with mastery motivation. They found that maternal over-c ontrol and intrusive behavior measured at the child age of 2 years was negatively related to children™s sustained attention at 2 years old. However, maternal over-control and intrusiveness di d not predict slower growth in children™s sustained attention development from age 2 to 4.5 y ears. In contrast, maternal warmth and responsiveness was positively associated with faste r growth in children™s sustained attention development. This pattern is consistent with our fi ndings. Another possible explanation supported by the findings of the current study is t hat maternal intrusive behavior may affect different domains of social and cognitive developme nt than does sensitivity. In the current study, maternal intrusive behavior predicted children™s la ter self-regulatory ability and general cognitive skills, but not mastery motivation. This implies that mastery motivation is a different construct from self-regulation and general cognitiv e skills. Feldman and colleagues (2009) argued that maternal sensitivity attenuated the effects of maternal depression on child social development. Ho wever, our findings showed no interaction effects of early maternal depressive symptoms (6 mo nths) and maternal parenting behaviors (i.e., maternal sensitivity and intrusiveness) at 24 month s. The negative effects of early maternal depressive symptoms on children™s later social and cognitive skills were not reduced by maternal sensitivity or exacerbated by maternal intrusive be haviors at the second year. According to our findings, maternal sensitivity and intrusiveness at 24 months partially mediated the effects of early maternal depressive symptoms on children™s la ter social and cognitive skills, except mastery motivation which was affected by only mater nal sensitivity. Early maternal depressive symptoms still negatively affected children™s later development, regardless of how sensitive or intrusive mothers were at 24 months. One implicatio n of these findings may be that focusing solely on the parenting behaviors of mothers experi encing, or at risk for, depression is not sufficient to prevent mothers™ mental health from i mpacting their children. Instead, early intervention may need to also focus directly on all eviating maternal depressive symptoms in order to foster children™s later social and cogniti ve development. The results of the current study showed that childr en™s self-regulation and general cognitive skills were affected by early maternal de pressive symptoms directly, as well as indirectly via maternal behavior including sensitiv ity and intrusiveness. However, the effect of early maternal depressive symptoms on later mastery motivation was fully mediated by only maternal sensitivity. This indicates that mastery m otivation is a separate construct with different predictors than self-regulation and general cogniti ve skills. Gender Differences We found gender differences in the relationship bet ween early maternal depressive symptoms and children™s later social and cognitive skills. Boys whose mothers had more early depressive symptoms displayed poor general cognitiv e skills, but boys™ self-regulation and mastery motivation at 36 months were predicted indi rectly via maternal sensitivity at 24 months. For girls, early maternal depressive symptoms did n ot have direct effects on any of the later outcomes. These results are consistent with previous research in which maternal depression affected boys™, but not girls™, later IQ scores (Milgrom et al., 2004). We also found that boys had lower scores for general cognitive skills than girls in g eneral. Thus, the direct and indirect negative effects of early maternal depressive symptoms via m aternal behavior identified in this study may explain boys™ lower cognitive skills. The current s tudy provides additional evidence consistent with previous research indicating that young boys a re more vulnerable to the effects of maternal depression than their female counterparts. Interven tionists should be aware that boys may be particularly vulnerable to their mothers™ depressiv e symptoms. Limitations and Future Directions The current study contained some limitations for co nsideration in future research. First, the measure of maternal depressive symptoms used in this study was based on report of short- term symptoms, and may lack information on the dura tion of symptoms (Hoffman, Crnic, & Baker, 2006); however, use of this measure at both 6 and 24 months may help to overcome this limitation. Second, this study did not measure mate rnal depression concurrently with children™s outcomes at 36 months; thus, the lack of significan t direct effects of maternal depression on children™s mastery motivation may be because master y motivation is more vulnerable to the effects of concurrent maternal depression. Moreover , other studies have found the effects of chronic maternal depression on maternal parenting a nd child development (e.g.,Campbell, Matestic, Von Stauffenberg, Mohan, & Kirchner, 2007 ). Therefore, future studies should examine the effects of concurrent maternal depressi ve symptoms, as well as the effects of chronic maternal depressive symptoms throughout ear ly childhood. Third, this study investigated two general maternal parenting behaviors. Further r esearch could define and further categorize sensitive and intrusive behaviors, such as verbal a nd physical intrusiveness, or distracting children™s attention, which may have more specific effects on children™s self-regulation, mastery motivation, and cognitive skills. Further, these mo re specific categories could provide a deeper understanding of the mediating effects of maternal sensitivity and intrusiveness in the relations between early maternal depression and children™s la ter social and cognitive development. Another limitation of the current study is the lack of inclusion of a measure of child temperament. Rothbart and Hwang (2005) argued that child temperament is related to motivation, including the temperament dimensions of surgency/ex traversion and negative affectivity that are associated with children™s approach, avoidance, int erest, and frustration. However, to examine the relations between temperament and mastery motiv ation was beyond the scope of the current study. Thus, future studies should consider the pos sibility that children™s temperament could affect the development of mastery motivation, and m ay also be related to maternal depression and children™s self-regulation. Finally, the majority of the mothers and children p articipating in the study were European American, thus the findings of the current study ma y not apply to mothers and children more generally. Therefore, future research should compar e effects of early maternal depression on children™s later mastery motivation and related dom ains across other ethnicities. Conclusions The current study shows the effects of early matern al depressive symptoms on children™s later social and cognitive development, specificall y mastery motivation, self-regulation, and general cognitive skills at the early preschool age . In addition, maternal sensitivity and intrusiveness mediated the relationship between ear ly depressive symptoms and children™s self- regulation and cognitive skills; however, maternal intrusive behavior did not affect the relations between early maternal depressive symptoms and chil dren™s later mastery motivation. The current study also provides evidence that boys are more vulnerable to the effects of maternal depressive symptoms than girls. 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The role of mastery motivation in the de velopment of executive function skills Mastery motivation refers to a intrinsic force with in children which helps them to sustain their attempts to master moderately challenging tas ks (Morgan, MacTurk, & Hrncir, 1995) and is associated with the development of both cognitive a nd social skills (Banerjee & Tamis-LeMonda, 2007; Zhou, Hofer, Eisenberg, Reiser, Spinrad, Fabe s, 2007; Deater-Deckard, Petrill, & Thompson, 2007). Further, mastery motivation is clo sely related to self-regulation. Barrett and colleagues (1993) have asserted that mastery motiva tion requires self-regulation abilities involving an affective component, engagement, and s ustained attention during attempts to achieve a goal. Similar to mastery motivation, executive function s kills are also necessary for a child™s goal-directed behavior and are associated with the self-regulation process. In addition, like mastery motivation, executive function skills are i mportant capacities in children™s socio- emotional development and academic achievement. How ever, little research has studied associations between mastery motivation and executi ve function skills. The current study examined whether or how mastery motivation promotes development of executive function skills in early childhood. The Development of Mastery Motivation Mastery motivation is a multifaceted and intrinsic force that drives an individual to make active and independent attempts to interact with th e world in order to master the environment or achieve goals Barrett & Morgan, 1995). In addition, mastery motiv ation helps children to learn new knowledge and skills, solve new problems, and m eet new standards (McCall, 1995). Barrett, MacTurk, and Morgan (1995) proposed that fimastery m otivation is not a static, stable, unitary trait, but rather a complex, malleable, processfl (p . 347). This is consistent with Barett and Morgan™s notion that behavior and affect relating t o mastery motivation can be seen during early development but the nature of mastery motivation tr ansforms as the child develops and these changes are affected by changes in cognition (1995) . Mastery motivation is elicited from uncertain situations in which children do not know whether they can achieve the goal. If they know they cannot attain the goal, they do not try t o master the goal. Further, it is important to distinguish the notion of mastery motivation from t hat of competence. Competence refers to an ability to do something, while mastery motivation i s the intrinsic force to make an attempt to obtain competence. Thus, successful achievement of the goal is not necessary in order to demonstrate mastery motivation (Barrett et al., 199 3; McCall, 1995). However, highly motivated children are more likely to learn successful strate gies than children with low levels of mastery motivation, which fosters children™s competence in problem-solving (Barrett & Morgan, 1995). Mastery motivation is an internal process that can not be observed directly, thus several individual behaviors serve as indicators when asses sing mastery motivation. Barrett and Morgan (1995) categorized indicators of mastery motivation into two major types: instrumental and expressive aspects of mastery motivation. Instrumen tal aspects of mastery motivation refer to behaviors that are used to attain a goal. A key ind icator of instrumental type is the length of time or the tendency that a child has to persist or focu s on mastering a new task. Other examples of instrumental aspects of mastery motivation are a pr eference for a challenging task or novelty, a desire for physical and/or cognitive control over t he environment, and children™s agency such as initiative and choices about activities and levels of engagement in tasks (Barrett & Morgan, 1995; Wigfield, Eccles, Schiefele, & Davis-Lean, 20 06). Expressive aspects of mastery motivation are emotions elicited during or after co nducting a task such as pleasure, interest, enthusiasm, or pride. Task pleasure is a main indic ator of expressive aspects of mastery motivation (Barrett & Morgan, 1995). Highly motivat ed children engage in the task enthusiastically and often smile during or after a moderately challenging task. Previous research has demonstrated that the social environment, especially maternal behavior is an important predictor of the developme nt of children™s mastery motivation (Busch- Rossnagel, Knauf-Jensen, & DesRosiers, 1995). For e xample, maternal supports for the child™s autonomy help children to have more opportunities t o challenge and succeed in tasks (Baumrind, 1971). Kelley, Brownell and Campbell (2000) support ed this assertion with evidence that children showed higher levels of mastery motivation when their mothers supported children™s efforts and their autonomy for the challenging task s. These maternal behaviors encourage children to face challenges for the mastery of acti vities so they were less likely to avoid challenging tasks. Neitzel and Stright (2003) also showed similar results. They found that maternal supportive behaviors such as support for c hildren™s autonomy and emotional encouragement during problem-solving tasks at presc hool were significantly associated with children™s task-persistence one year later, which i s a key instrumental indicator of mastery motivation. Preschool aged children sustained effor t and maintained interest in tasks more when their mothers supported their autonomy and gave emo tional encouragement. This variability in degree of mastery motivation indicates that the dev elopment of mastery motivation is affected by parental socialization. In particular, mothers™ sen sitive and responsive behaviors may encourage children to explore, access, and persistently engag e in activities, which in turn facilitates children to gain more knowledge and new skills. This researc h is consistent with the idea that securely attached children use their mothers as a secure bas e from which to explore (Risken-Walraven et al., 1993). Motivation researchers have emphasized the importan t role of emotion in understanding children™s mastery motivation (Meyer & Turner, 2006 ; Schutz & Lanehart, 2002; Turner, Meyer, & Schweinle, 2003). Bronson (2000) explains that as children experience pleasure in persistence and mastering tasks, their mastery motivation incre ases and they seek more opportunities to take on challenging tasks, which in turn facilitates the development of new knowledge and skills (Bronson, 2001). Spangler (1989) supports this asse rtion as well; he emphasized that the emotional quality of an experience is important to a child™s task persistence. For example, children who experience and show more positive affe ct are more likely to persist in their activities (Spangler, 1989). In contrast, negative emotions such as sadness and anxiety are associated with the withdrawal system, so these emo tions may cause children to avoid challenging tasks (Davidson, Jackson, & Kalin, 2000 ). Deater-Deckard and colleagues (2007) demonstrated the effects of negative emotion on mas tery motivation. According to their findings, children who had higher levels of anger/frustration were likely to display lower levels of task persistence. However, the relationship between emot ion and mastery motivation may be moderated by children™s ability to regulate emotion s. Emotional regulation is defined as fithe capacity to regulate arousal appropriately in order to reach goalsfl (Bronson, 2000, p. 58). In cases in which a child does not succeed in a challe nging task and feels frustrated, a child who has better emotional regulation ability may control thi s negative emotion appropriately to complete the task, which may enable him or her to keep their attention on tasks and have more opportunities to learn and master new skills and kn owledge. Mastery motivation is the force for a child to persist in a challenging, and possibly emo tion-evoking task. Thus, children™s emotional regulatory abilities may promote their mastery moti vation. However, to date, no studies have examined this association in young children. The Role of Mastery Motivation in Executive Functio n In addition to skills in regulating emotions, execu tive function skills develop throughout early childhood and may have an important relations hip to mastery motivation. Executive function (EF) is an umbrella term for complex cogni tive processes related to goal-directed, purposeful, and problem-solving behaviors (Hughes & Graham, 2002; Gioia et al, 2000;Meltzer, 2007). EF is associated with the prefrontal cortex which is one of the late developing brain areas; this area functions to regulate thoughts and behavi or, and becomes the seat of inhibitory control (Raaijmakers et al., 2008). EF consists of several dissociable components including working memory, inhibition, and cognitive flexibility (Diam ond, 2006). Working memory indicates an ability to hold information in mind, recall it, and use it to guide behavior. Inhibitory control refers to an ability to suppress a dominant respons e and/or initiate a subdominant response. Cognitive flexibility is an ability to shift one me ntal set to another. These components have different developmental trajectories and are differ entially linked to areas of the prefrontal cortex (Diamond, 2006). However, other researchers support a unitary EF model in which EF is a unitary construct with constituent sub-processes. F or example, Posner and Rothbart (2001) propose that a central attention system manages the se sub-processes and plays an important role in changes in EF abilities from two to six years. P revious research supports their assertion with evidence that performance on a variety of EF tasks is strongly associated with a central attention process (Garon, Bryson, & Smith, 2008). Recently, r esearchers have attempted to integrate these two perspectives. Miyake et al. (2000) proposed the integrative EF model which includes attention as a common EF mechanism and three compon ents such as working memory, inhibition, and set shifting. Thus, the functioning of these co mponents are seen as partially independent but correlated with each other. The first five years of life are an important peri od for the development of executive function, with basic component skills of EF emergin g before three years of age (Garon et al., 2008). EF skills show rapid growth in the last half of the first year and from three to six years of age (Diamond, 2001). According to Garon et al. (200 8), working memory is observed first. Simple working memory capacity, such as the ability to hold a representation in mind over a delay, occurs before 6 months, and more complex wor king memory (i.e., updating or manipulation of representation) develops gradually. Over the preschool period, children are able to hold more representations in mind. Inhibition sk ills develop following working memory. Children show simple inhibition skills during the f irst year but children are not able simultaneously to use a rule held in mind to inhibi t a dominant response and perform a subdominant response until the age of two years. Ra pid development of inhibition ability occurs during the preschool period. Previous research supp orted this assertion with evidence that children between three and five years display bette r performance on inhibition and delay of gratification tasks than younger children (Garon et al., 2008). Cognitive shifting, which refers to the ability to adjust behavior quickly and flexibly to changing situations (Davidson, Amso, Anderson, & Diamond, 2006), is the most complex EF component and develops last. Further, it is affected by the development of working memory an d inhibitory control. Even three-year-old children are often observed to have a difficulty sw itching from one task set to another (Wiebe et al., 2011). After three years old, development of t he attention system and its connectivity with other brain areas involved in EF skills enable chil dren to integrate and coordinate these EF basic skills (Garon et al., 2008). How does a child™s mastery motivation link to hi s or her executive function skills? It could be that children™s mastery motivation promote s development of their executive function skills. Persistence is considered an indicator of h ighly motivated children and is one behavioral indicator measured as mastery motivation. It may be that when a child persists in a challenging task longer, he or she has more chances than a chil d who easily gives up to use and practice his or her cognitive skills and learn new skills and kn owledge. Duckworkth and Seligman (2005) found that children who are more engaged in learnin g tasks tend to display better academic achievement than those who are not engaged. During a task, children will apply several strategies in order to have success at a task and they may fin d an appropriate solution through their attempts. This process would affect development of EF skills like planning strategies to solve problems. Wang and Barrett (2013) also asserted tha t children™s fiactive trial-and-error explorationsfl with objects help children refine the ir existing knowledge and process new information that would apply to future problem solv ing (p.349). Intrinsic motivation, like mastery motivation, prom otes children™s high quality attention to tasks and optimal use of meta-cognitive strategi es in solving problems (Larson & Rusk, 2011). For example, middle school children with greater in trinsic motivation were shown to apply more self-regulatory and cognitive strategies in academi c tasks (Pintrich & De Groot, 1990). While, limited research has examined the relationship betw een EF skills and mastery motivation directly, especially in young children, there is evidence for this association in school-aged children. Brock and colleagues (2009) showed significant associatio ns between mastery motivation and EF skills in kindergarten children. According to their findin gs, teachers rated children with higher EF skills including executive attention, inhibitory co ntrol, and working memory, as children with longer persistence in difficult tasks, less distrac tibility, better autonomy (works well independently), and self-control. Mizuno and collea gues (2011) found that well developed mastery motivation in elementary school children co rrelated with executive function skills such as abilities to retrieve learned materials, spatial working memory, and visual scanning. These studies assessed mastery motivation and EF skills c oncurrently, and were thus limited to showing concurrent associations. Thus, the present study wi ll fill a gap in the research by examining whether early childhood mastery motivation predicts children™s executive function skills at the first grade, which may elucidate the relationship b etween early mastery motivation and later executive function skills. Mastery Motivation as a Mediator Another possible role of mastery motivation in the development of executive function skills is that it may mediate the effects of other predictors, such as maternal behavior or children™s emotional regulatory ability, on executi ve function skills. Emotion regulation affects children™s executive fun ction skills, because many aspects of human thought and actions are affected by emotions (Bronson, 2000). Positive emotions like joy are associated with creative thoughts and actions a nd help children broaden their cognitive and social resources (Fredrickson, 2001). In contrast, negative emotions like anger interfere with children™s higher order cognitive process such as p roblem solving and memory (Blair, 2002). Thus, the ability to regulate emotion, especially n egative emotion, during challenging tasks can facilitate one™s cognitive processing including org anizing one™s thoughts and behaviors, and leaning (Blair & Diamond, 2008; Carlson & Wang, 200 7). For example, Carlson and Wang (2007) assessed the associations between emotional regulation ability (as measured by a child™s control of emotional expression and their emotion u nderstanding) and inhibitory control in four- and five-year-old children. They found that childre n with higher levels of emotional regulatory skills showed better ability to suppress dominant r esponses and activate subdominant responses after controlling for age and verbal ability. Like mastery motivation, children™s executive funct ion skills are also influenced by maternal behavior such as maternal sensitivity, aut onomy support, and intrusiveness. Bernier, Carlson, and Whipple (2010) found that children who se mothers were more sensitive at 12 months showed better performance on EF tasks at 26 months. In addition, maternal autonomy supporting behaviors at 15 months of age predicted child™s better scores in EF tasks at 18 and 26 months after controlling covariates such as materna l education and other child™s cognitive function. Further, Graziano, Keane, and Calkins (20 10) found evidence for the effects of early maternal behavior on later inhibitory control. In p articular, children whose mothers were more warm and responsive and less intrusive at age two y ears showed higher levels of effortful control at 5.5 years. The research reviewed above indicates that both early maternal behavior (i.e., sensitivity and autonomy supporting behavior) and c hildren™s emotion regulation promote children™s mastery motivation and executive functio n skills; but that mastery motivation may play a role as a mediator of early maternal sensiti vity and children™s emotional regulation on later children™s executive function skill. Current Study Despite evidence of associations between children™s mastery motivation and their executive function skills, few studies have examine d these relations longitudinally, particularly in young children. In addition, previous research s hows that maternal sensitivity and children™s emotional regulation affect both children™s mastery motivation and executive function skills, but limited research has studied these components toget her, particularly longitudinally in young children. In the current study, I propose that high ly motivated children have more opportunities to apply their existing cognitive resources to task s, which will influence the development of their executive function skills. I also examined whether children™s mastery motivation mediates the effects of early maternal sensitivity and children™ s emotional regulation on children™s later executive function skills. In addition, I investiga ted whether different executive function skills are affected differentially by early predictors and mastery motivation. Although both maternal sensitivity and children™s e motion regulation have been studied as factors in the development of children™s mastery motivation and executive function skills, few studies have examined these constructs together. Th e specific relationship between maternal sensitivity and children™s emotional regulation may contribute to promoting children™s mastery motivation and executive function skills. For examp le, negative effects of children™s lack of emotional regulation may be buffered by maternal se nsitivity, or children™s emotion regulation may moderate the effects of maternal sensitivity on children™s mastery motivation and executive function skills. The current study will be the firs t to examine these interactions. In the current study, I examined whether there are significant int eractions between maternal sensitivity and children™ emotional regulation on children™s master y motivation and executive function skills. Method Participants The data in the current study come from the Nationa l Institute of Child Health and Human Development (NICHD) Study of Early Child Care and Youth Development (SECCYD), Phases I and II. Between January and November of 19 91, mothers and children were recruited at ten locations: Little Rock, AR; Irvine, CA; Lawrenc e, KS; Boston, MA; Philadelphia, PA; Pittsburgh, PA; Charlottesville, VA; Morganton, NC; Seattle, WA; and Madison, WI. These mothers and children met the following criteria: (a ) the mother was over 18 years old, (b) the mother could speak and understand English, (c) the mother did not have any substance-abuse problems, (d) the child was a singleton, (e) the ch ild did not have any disabilities, and (f) the child had not been hospitalized for more than 7 day s. Phase 1 data were collected when children were 1 month, 6 months, 15 months, 24 months, and 3 6 months of age. During Phase 1 (1991- 1994), 1,364 children and their families participat ed. Retention of the sample for the following Phase II was good; 1,226 children and their familie s continued participation in Phase II until children were in the first grade. Phase II data wer e collected when children were 54 months old, in kindergarten, and in first grade. The mothers™ m ean age when children were 1 month of age was 28.7 years (SD = 5.56) and the mean maternal ed ucation at this time was 14.5 years. The majority of mothers and children were White (n = 79 5 mothers or 84.8%; n=778 children, or 82.9%). The mean total family income is $39,371 (SD = $33,239) when children were 1 month, and $54,539 (SD = $43,747) when children were 36 mo nths of age. Measures Each measure is described below. Descriptive inform ation for all the main variables of interest are provided in Table 5, including means, standard deviations, and ranges. Table 5. Descriptive Statistics for the Main Study Variables Variable Mean SD Range Maternal sensitivity 17.39 2.65 4-21 Child Emotion-Regulation Defiance 1.15 0.52 1-5 Negative affect 1.19 0.55 1-5 Child Mastery Motivation Persistence 4.74 1.28 1-7 Autonomy 4.64 1.13 1-7 Child Executive Function Skills Impulsive responding 0.03 0.04 0.0 - 0.39 Short-tem memory 101.66 13.81 43-161 Long-term memory 99.17 14.90 2-154 Problem solving 14.42 6.76 0-34 Maternal sensitivity . Maternal sensitive behavior was measured during a s emi- structured mother-child interaction task. The mothe r was instructed to show her child toys in three sequentially numbered boxes. Drawing material s including markers and paper were in the first box, and dress up cloths and a cash register were in the second box. The last box contained Duplo block set with a picture of a model. The moth er™s and child™s behaviors were videotaped for 15 minutes, and trained observers coded materna l behaviors using a seven-point rating scales (1 = very low, 7 = very high). In this study, score s on three maternal behaviors are used to assess maternal sensitivity. First, maternal supportive presence indicated the level of maternal emotional support and expression of positive regard . Mothers with high scores on this scale are thought to provide verbal and physical encouragemen t and to be concerned about their children™s emotional needs. Second is mother™s respect for the child™s autonomy . Mothers with high levels of this characteristic respect the child™s individu ality, motives, and perspectives. These mothers tended to form mutually negotiated relationship wit h their children. The last maternal behavior evaluated to contribute to the maternal sensitivity score was mother™s hostility , which reflected the mother™s expression of anger, discounting, or r ejecting of the child. Intra-class correlation coefficients (ICC; Winer, 1971) were used to measur e inter-rater reliability for these three variables; ICCs were .81 for supportive presence, . 71 for respect for child™s autonomy, and .82 for hostility. The current study used a maternal se nsitivity composite score comprised of these three behaviors in the following way: supportive pr esence + respect for child™s autonomy Œ hostility. Emotional regulation . The child™s emotional regulatory ability was assess ed during a clean-up episode at 36 months of age. The mother an d her child were asked to clean up toys with which the child played during a solitary play episo de. The child™s behaviors were videotaped for 5 minutes. Using a five-point rating (1 = very unch aracteristic, 5 = very characteristic), trained observers coded the child™s behaviors for complianc e, autonomy bids/self assertion, defiance, passive noncompliance, positive affect, and negativ e affect. In the current study, defiant noncompliance and negative affect scores were used as indicators of the child™s emotional regulation (NICHD, 2004). Defiant behavior was indi cated by a child™s hostile, angry or affectively negative resistance, or response to the mother™s demands, including yelling, throwing things, kicking, etc. Scores on a child™s defiance and negative affect (i.e., distress, anger, or hostility) were summed, and the composite score was used as the measure of the child™s emotional regulation. Children with higher scores w ere considered to have poor abilities to regulate their emotions. Mastery motivation . The child™s mastery motivation was assessed durin g mother-child interaction at 54 months that was videotaped in a s emi-structured 15-minute observation. The mother and her child were asked to complete a maze using an Etch-A-Sketch, and to build several identical towers with blocks of various sha pes and sizes based on the instruction. These tasks were challenging to the children. The third t ask was a semi-structured play session between mother and child. They were instructed to play toge ther with a set of six hand puppets. The child™s persistence and agency behavior in these th ree tasks was used to assess mastery motivation in the current study. The child™s persistence was rated on a scale based on the degree to which he or she engaged in a task, and agency was indicated by the ability to make a choice to act during a challenging task. The trained observer s coded these behaviors using 7-point rating scales (1 = very low, 7 = very high). Inter-rater r eliability was .86 for child persistence and .84 for child agency (ICC; Winer, 1971). Scores on a ch ild™s persistence and autonomy are summed and the composite score was used as the measure of the child™s mastery motivation. Executive function skills . Children™s executive function skills were assesse d in the areas of impulsive responding , memory (short-term and long-term), and planning/problem solving skills when children were in first grade. Impulsive responding was measured with the Continuous Performance Task (CPT) which was an 8.5- minute computer-generated task. Dot matrix letter stimuli were presented in 30 blocks o n a 2-inch square screen. Ten stimuli were presented in each block for 200 ms with an inter-st imulus interval of 1,500 ms. Children were asked to press the red button when they saw the tar get stimulus (letter X), which randomly appeared twice in each block. Impulsive responding was calculated from the proportion of incorrect response to a non-target. The subset of Woodcock-Johnson Psycho-Educational B attery (WJ-R; Woodcock & Johnson, 1989) was used to examine children™s short -term and long-term memory. In this test, short-term memory was defined as the ability to rem ember and repeat simple words, phrases, and sentences and was measured with the Memory for Sent ences subtest. Long term memory was assessed using the Memory for Names subtest which m easures a child™s ability for long-term retrieval. The Tower of Hanoi task (TOH; Welsh, 1991) was used to assess the child™s planning/problem-solving skill. The child was asked to construct a tower on a specified peg using rings with different diameters and colors fol lowing several specific rules that no larger rings could be on smaller rings and only one ring c ould be moved at a time. This task requires the child to think ahead and plan an organized sequ ence of moves in order to transform an initial configuration of rings into the tower that he or sh e is asked to build. The child can try a maximum of six puzzles that could be solved within 1 to 6 trials. Each trial allowed using a maximum of 20 moves. A planning efficiency score fo r each puzzle was based on the number of trials the child attempted to achieve two successiv e optimal solutions. When children solved a puzzle on Trials 1 and 2 they received six points; five points were given to children who complete a puzzle on Trial 2 and 3, and so on. Chil dren could receive a score between 0 and 6 for each puzzle and between 0 and 36 for the six pu zzles. Children with higher total planning efficiency scores were considered to have greater p lanning/problem-solving skills. Data-analytic strategy Structural equation modeling (SEM) with AMOS 17.0 w as used to test whether there were interaction effects between maternal sensitivi ty and children™s emotional regulatory ability on children™s later executive function skills. Then , mediational model was tested such as whether children™s mastery motivation mediated the effects of early maternal sensitivity, a child™s earlier emotional regulatory ability, and the interaction b etween sensitivity and emotion regulation on the child™s later executive function skills. First, the direct path model was fit in order to assess the direct associations between first grade executi ve function skills and early maternal sensitivity, child emotional regulatory ability, and their inter action. Second, the partial mediation model (with all paths estimated) was used to test the dir ect and indirect effects of early maternal sensitivity, the child™s emotional regulatory abili ty, and their interaction, on the child™s later executive function skills via child™s mastery motiv ation. Models were evaluated based on several criteria. First, the 2 value, as an indicator of overall fit, was assessed comparing the covariances within the hypothesized model and the null model. T he probability value related to 2 indicates the likelihood of obtaining a 2 value that exceeds the 2 value when the null model is true. Therefore, a low and statistically nonsignificant 2 value represents a good model fit (Schumacker & Lomax, 2010). The comparative fit ind ex (CFI) and root mean square error of approximation (RMSEA) were also calculated to evalu ate models. For a good model fit, CFI should be .95 or above; RMSEA should be .06 or belo w (Hu & Bentler, 1999). Figure 8 shows the model that the current study tested. Figure 8. The Conceptual Model Results Preliminary Analyses Table 6 provides the bivariate Pearson correlations among the main variables. Children™s emotional regulation was assessed using their defia nce and negative affect during the clean up episode, and these variables were highly correlated . Children™s persistence and autonomy were measured in order to assess their mastery motivatio n at 54 months, and these two variables were also highly correlated. Children™s executive functi on skills included impulsive responding, short- term and long-term memory, and planning/problem sol ving skills, which were significantly correlated. As expected, early maternal sensitivity at 36 months was significantly correlated with children™s emotional regulation abilities (i.e., de fiance and negative affect) at 36 months, mastery motivation (i.e., persistence and autonomy) at 54 m onths, and with executive function skills including impulsive responding, short-term and long -term memory, and planning/problem solving skills in the first grade. Children whose m others were more sensitive to them at 36 months were likely to show better emotional regulat ion abilities at 36 months, mastery motivation at 54 months, and executive function ski lls in the first grade. Early child defiance was correlated only with later impulsive responding, wh ile early child negative affect was negatively linked to both mastery motivation (persistence and autonomy) at 54 months and to problem solving skills in the first grade. Finally, childre n™s mastery motivation was positively related to their executive function skills (i.e., short-term a nd long-term memory, impulsive responding, and problem solving skills) in the first grade. Table 6. Bivariate Pearson Correlations among Main Variables Main Variable 1 2 3 4 5 6 7 8 9 1. Maternal sensitivity 1 2. Child defiance -.084 * (N=900) 1 3. Child negative affect -.119 ** (N=900) .722 ** (N=908) 1 4. Child persistence .165 ** (N=880) -.051 (N=877) -.096 ** (N=877) 1 5. Child autonomy .192 ** (N=880) -.058 (N=877) -.126 ** (N=877) .792 ** (N=901) 1 6. Child impulsive responding -.245 ** (N=911) .082 * (N=908) .030 (N=908) -.088 ** (N=901) -.062 (N=901) 1 7. Child short-term memory .132 ** (N=911) .010 (N=908) -.042 (N=908) .123 ** (N=901) .141 ** (N=901) -.086 ** (N=938) 1 8. Child long-term memory .322 ** (N=911) -.050 (N=908) -.061 (N=908) .131 ** (N=901) .135 ** (N=901) -.127 ** (N=938) .286 ** (N=938) 1 9. Child problem-solving skills .123 ** (N=911) -.065 (N=908) -.076 * (N=908) .140 ** (N=901) .131 ** (N=901) -.153 ** (N=938) .112 ** (N=938) .167 ** (N=938) 1 *** p < .001, ** p <.01, * p < .05 Path Analysis Direct Path Model . The direct path model was tested to examine wheth er early maternal sensitivity and children™s emotional regulation dir ectly predicted children™s later executive function skills including impulsive responding, sho rt-term and long-term memory, and problem solving skills. In addition, in order to assess int eraction effects of maternal sensitivity and children™s emotional regulation, an interaction var iable (maternal sensitivity x child emotional dysregulation) was created and added to the model. The results of the direct path model are summarized in Figure 9. The model fits the data wel l ( 2[2]= 5.07, ns , CFI = 1.00, RMSEA= .04). Partially consistent with the hypothesis that mater nal sensitivity and children™s emotional regulation linked to children™s later executive fun ction skills, maternal sensitivity at 36 months predicted children™s short- and long-term memory, h owever, it did not affect other executive function skills. Children™s emotional regulation ab ilities at 36 months predicted only impulsive responding. Other executive function skills were no t related to children™s early emotional regulation abilities. There were some significant interaction effects bet ween maternal sensitivity and child emotional regulation on children™s executive functi on skills. Children™s emotional regulation moderated the effects of maternal sensitivity on ch ildren™s long-term memory. In other words, for children with low emotional regulation, materna l sensitivity did not affect children™s long- term memory, but for children with low dysregulatio n (those who are highly regulated), maternal sensitivity affects their long-term memory such tha t mothers who are more sensitive have children with better long-term memories. For the effects on children™s impulsive responding, there was no direct relationship between maternal sensitivity and children™s impulsi ve responding when the interaction (maternal sensitivity x child dysregulation) was in the model . This result shows that maternal sensitivity moderates the effect of children™s emotion regulati on on children™s impulsive responding; that is, when mothers are highly sensitive, there is no impa ct of children™s early emotional regulation on their impulsiveness, but when mothers are less sens itive, children™s lower levels of emotional regulation leads to high impulsive responding. Figure 9. The Direct Path Model. This model shows t he direct effects of early maternal sensitivity and child emotional regulation and thei r interaction on later children™s executive function skills. *** p <0.001, ** p < 0.01, * p <0.05 Mediated Models . The mediated model was tested to investigate whethe r children™s mastery motivation at 54 months mediated the relati onships between first grade executive function skills and early maternal sensitivity, children™s emotional regulation, and t heir interaction. First, the fully directed model was te sted but the model did not fit the data ( 2[14] = 161. 96, p < 0.05; CFI = .960; RMSEA=0.106). Then, the partially meditated model was tested to investigate whether earlier maternal sensitivity , children™s emotional regulation, and their interaction affected children™s late executive func tion skills directly and indirectly via children™s mastery motivation at 54 months. The partial medita tion model is summarized in Figure 10. Although the partially mediated model fit the data well statistically ( 2[2]=4.65, ns , CFI = 1.00; RMSEA=0.04), none of independent variables predicte d mastery motivation in the model. Mastery motivation promoted some of EF skills, incl uding problem solving and short- and long- term memory, but did not mediate the effects of mat ernal sensitivity, child™s emotional regulation ability, and their interaction on later child™s EF skills. This is consistent with the idea that mastery motivation is a separate construct, an d is not a function of children™s early emotional regulation. Interestingly, children™s problem solving skills we re affected only by their mastery motivation. Children™s early emotional regulation a nd maternal sensitivity did not predict later problem solving skills, while early maternal sensit ivity predicted later memory skills and children™s emotional dysregulation led to high impu lsive responding. Like the direct path model, there were interaction effects between early maternal sensitivity and children™s emotional dysregulation on children™s long-term memory and impulsive responding. Early maternal sensitivity mo derated the effects of children™s emotional dysregulation on their impulsive responding. Childr en with poor emotional regulation abilities showed higher levels of impulsive responding when t heir mothers were less sensitive. However, there was no influence for children who had more se nsitive mothers. With regard to children™s memory, early maternal sensitivity led to better lo ng-term memory when children regulated their emotion well at 36 months. Figure 10. The Partial Mediated Model. This model s hows how children™s mastery motivation affects the relations of predictors (i.e., early ma ternal sensitivity, children™s emotional regulation and their interaction) to children™s executive func tion skills. *** p <0.001, ** p < 0.01, * p <0.05 Discussion Little research has addressed the role of children ™s mastery motivation in the development of executive function skills in early c hildhood. Moreover, even though previous research has shown that maternal sensitivity and ch ildren™s emotional regulation each predict the development of mastery motivation and executive fun ction skills, few empirical studies have examined these predictors together, along with thei r possible interactions. The current study, using a large and diverse sample of mothers and the ir children, directly examined links from early maternal sensitivity and children™s emotional regulation to children™s later executive function skills. Moreover, this study asked whether there were interaction effects between maternal sensitivity and child emotional regulation on the development of executive function skills. In addition, the current study used a longi tudinal design to assess whether children™s mastery motivation mediated these relationships. Th e current study findings confirm the unique role of mastery motivation in the development of ex ecutive function skills, and highlight the ways that maternal sensitivity moderates the effect s of children™s emotional regulation abilities on the development of a set of executive function s kills. Maternal Sensitivity The current findings confirmed that early maternal sensitivity predicted children™s later executive function skills, especially memory skills . These findings are consistent with those of Gauvain (2001) who found that maternal scaffolding, such as sensitive responding and supporting children™s autonomy, contribute to the d evelopment of children™s memory skills including encoding and storage of information. Chil dren may learn from mothers™ behavior how to encode and use information held in mind. Maternal sensitivity did not affect children™s late r impulsive responding. These findings are consistent with those of Granziano, Keane, and Calkins (2010) who found that maternal warmth and responsiveness did not predict children™ s impulsivity. However, they found that maternal over-control and intrusiveness influenced children™s impulsive behavior. Unlike maternal intrusiveness, maternal sensitivity may in directly affect children™s control of impulsive behavior. The current results showed that mastery m otivation did not mediate the relation of early maternal sensitivity to children™s later impu lsive responding. Thus, maternal sensitivity may be indirectly related to children™s executive f unction skills through child skills other than mastery motivation which was tested in the current study. For example, Matte-Gagné and Bernier (2011) found that children™s expressive voc abulary mediated the effects of early maternal sensitivity, especially maternal autonomy support, on children™s later impulsive responding. According to them, maternal autonomy su pport promoted children™s language skills which children can use to control their impulsive b ehaviors. Problem-solving skills were not influenced by early maternal sensitivity. The problem- solving task in the current study was the most comp lex task assessed, and required children to integrate other executive function skills including working memory. Thus, children™s problem- solving skills Œ as measured in the current study Œ are influenced by maturation of other executive function skills. In the current study, we found that maternal sensitivity promoted the development of these other executive function skill s, including short-term memory, and thus may indirectly affect problem-solving through these oth er skills; however, testing these additional meditational effects was beyond the scope of the cu rrent study. An NICHD study (2005) suggests another possible explanation for the lack of significant relationship. Toddlers and preschool-age children may not be ready to take adv antage of their family environment, such as maternal sensitivity, to comprehend and learn the c omplex processes to solve problems. Thus, children could benefit more from later environmenta l input for developing problem-solving skills, but variation in early maternal sensitivity may not yet influence problem-solving in early childhood. Another possible explanation is that mat ernal sensitivity may be indirectly related to children™s later problem solving skills. For exampl e, Hammond and colleagues (2011) found that maternal scaffolding, including supportive and resp onsive behaviors, at age 2 affected children™s problem-solving skills at age 4 indirectly via the child™s verbal ability at age 3. Like the effects on impulsive responding, maternal supportive and re sponsive behaviors may promote children™s verbal ability such as self-directed speech, which in turn facilitates children™s ability to plan and organize their thoughts and regulate their behavior for solving problems. The current study did not examine these relationships, thus future study is needed to clarify this mechanism. The current study findings show that early maternal sensitivity moderated the effects of children™s emotional dysregulation on their impulsi ve responding. Children who had poor emotional regulation abilities and whose mothers we re less sensitive at 36 months displayed higher levels of impulsive responding at the first grade. On the other hand, in the context of more sensitive mothers, there was no influence of childr en™s emotion regulation on their impulsive responding. Previous research has shown maternal be havior such as warmth and responsive behavior buffers the negative effects of emotion re gulation on attention capabilities (Graziano, Calkins, & Keane, 2011) which play an important rol e in the development of executive function skills from two to six years (Posner & Rothbart, 20 00). The current study extends previous work by providing the evidence that maternal sensitivity buffered the effects of children™s emotional dysregulation on the executive function skill of im pulsive responding. Children™s Emotional Regulation As expected, early emotional regulation predicted later impulsive responding, which is consistent with previous research. Graziano and col leagues (2010) found that children with better emotional regulation skills showed low levels of be havioral impulsivity and greater improvement in reactive control over time. This indicates that children who, early on, experience successful regulation of their emotions can better control the ir behavior later. Children can learn some skills or strategies, such as self-talk, to modulate their emotion. Children with better emotion regulation abilities may use these skills more easi ly, which allows them to better control their impulsive behavior. Children™s early emotional regulation did not affec t later memory skills and problem- solving skills in the current study. Although Blair (2002) asserted that emotion regulation promotes executive functions, emotion regulation ma y not directly affect children™s memory and problem-solving skills. Researchers often categoriz e executive processes into two types: cool executive processes or hot executive processes. Coo l executive processes are associated with cognitive, abstractive, and decontextualized proble ms. Hot executive processes are involved in affective aspects of executive functioning (Aelazo, Qu, & Muller, 2004). Children™s early emotional regulation may facilitate the development of hot executive processes more than cool executive processes. Our results support this possi bility with the evidence that emotional regulation did not predict later memory skills and problem-solving skills but control of impulsive responding. The current study findings showed children™s early emotional regulation moderated the effects of maternal sensitivity on children™s later memory skills, especially long-term memory. That is, early maternal sensitivity led to better l ong-term memory when children regulated their emotion well at 36 months. No significant effects were found for children with poor emotional regulation abilities, which indicated that children ™s emotional regulation enhances the positive effects of early maternal sensitivity on later chil dren™s long-term memory. Relating the Child™s Mastery Motivation to Developm ent of Executive Function Skills Children™s mastery motivation predicted their lat er executive function skills of short- and long-term memory and problem-solving. Previous rese arch showed that mastery motivation promoted recall of information for deep processing on a memory task (DiCintio & Parkes, 1997; Graham & Golan, 1991). Our current study extends th is relationship by providing the evidence that mastery motivation affects later memory skills including short-term and long-term memory for young children. Further, children™s problem-sol ving skills were influenced by mastery motivation. According to Rogoff, Mistry, Goncu, and Mosier (1993), children™s successful experience of solving difficult tasks helps them to internalize the skills required for such tasks. Children™s mastery motivation drives them to attemp t difficult tasks, in which they have more opportunities to practice and internalize new knowl edge and skills, which in turn facilitates their executive function skills related to problem-solvin g. In the current study, mastery motivation did not me diate the effects of early maternal sensitivity or children™s emotional regulation on c hildren™s later executive function skills. This result indicates that the function of mastery motiv ation does not overlap with children™s early emotional regulation and is a separate construct pr omoting executive function skills. However, mastery motivation predicted three executive skills , including short-term and long-term memory and problem-solving, which emotion regulation did n ot; on the other hand, emotion regulation predicted control of impulsive responding which mas tery motivation did not. The fact that mastery motivation and emotional regulation predict separate executive function skills further strengthens the conclusion that these are separate constructs. Limitations The current study had some limitations which shoul d be considered in future research. First, this study measured only instrumental aspect s of mastery motivation (i.e., persistence and autonomy). Including expressive aspects of mastery motivation could help to understand the role of mastery motivation more clearly, and these may b e more related to children™s emotion regulation. Second, assessing other maternal behavi ors like intrusiveness may give more information about the development of children™s mas tery motivation and executive function skills. Third, we only examined longitudinal effect s of maternal sensitivity and children™s emotional regulation on mastery motivation and exec utive function skills, rather than including concurrent or short-term effects. Comparing short-t erm and long-term effects of maternal sensitivity and children™s emotional regulation on children™s skills could prove informative for promoting children™s mastery motivation and executi ve function skills. Finally, the majority of mothers and children participating in the study wer e European American, so the current study findings may apply only to this segment of the popu lation, rather than mothers and children more generally. Conclusion The current study shows the unique role of mastery motivation in the development of executive function skills. In particular, mastery m otivation and emotion regulation influence separate executive function skills, providing evide nce that they are separate constructs. Moreover, the current study indicates that maternal sensitivi ty moderate the effects of children™s emotional regulation abilities on the development of executiv e function skills such that when mothers are highly sensitive children™s dysregulation does not hamper their executive function skills, whereas when mothers are not sensitive, children must be we ll-regulated in order to develop high levels of executive function skills. The findings of this study contribute to a more understanding of the roles of maternal sensitivity and children™s intern al characteristics Œ self-regulation and mastery motivation Œ in the development of executive functi on skills. REFERENCES REFERENCES Barrett, K. C., MacTurk, R. H., & Morgan, G. A. (19 95). Concluding comments on mastery motivation: Origins, conceptualizations and applica tions. In R. H. MacTurk & G. A. Morgan (Eds.), Mastery motivation: Origins, concept ualizations, and applications (Vol. 12, pp. 339-359). Westport, CT: Ablex Publishing. Barrett, K. C., & Morgan, G. A. (1995). Continuitie s and discontinuities in mastery motivation during infancy and toddlerhood: A conceptualization and review. In R. H. MacTurk & G. A. Morgan (Eds.), Mastery motivation: Origins, conceptualizations, an d applications (Vol. 12, pp. 57-93). Westport, CT: Ablex Publishin g. Barrett, K. C., Morgan, G. A., & Maslin-Cole, C. (1 993). Three studies on the development of mastery motivation in infancy and toddlerhood. In D . J. Messer (Ed.), Mastery motivation in early childhood: Development, measurement and so cial processes (pp. 83Œ108). London: Routledge. Baumrind, D. (1971). Current patterns of parental a uthority. Developmental Psychology, 4 (1p2), 1-103. Bernier, A., Carlson, S. M., & Whipple, N. (2010). From external regulation to self-regulation: Early parenting precursors of young children's exec utive functioning. Child Development, 81 (1), 326-339. Blair, C. (2002). School readiness: Integrating cog nition and emotion in a neurobiological conceptualization of children's functioning at scho ol entry. American Psychologist, 57 (2), 111-127. Blair, C., & Diamond, A. (2008). Biological process es in prevention and intervention: The promotion of self-regulation as a means of preventi ng school failure. Development and Psychopathology, 20 (3), 899-911. Blankson, A. N., O'Brien, M., Leerkes, E. M., Marco vitch, S., Calkins, S. D., & Weaver, J. M. (2013). Developmental dynamics of emotion and cogni tion processes in preschoolers. Child Development, 84 (1), 346-360. Brock, L. L., Rimm-Kaufman, S. E., Nathanson, L., & Grimm, K. J. (2009). The contributions of 'hot' and 'cool' executive function to children's a cademic achievement, learning-related behaviors, and engagement in kindergarten. Early Childhood Research Quarterly, 24 (3), 337-349. Bronson, M. B. (2000). Self-regulation in early childhood: Nature and nurt ure . New York: The Guilford Press. Busch-Rossnagel, N. A., Knauf-Jensen, D. E., & DesR osiers, F. S. (1995). Mothers and others: The role of the socializing environment in the deve lopment of mastery motivation. Mastery motivation: Origins, conceptualizations, an d applications, 12 , 117-145. Carlson, S. M., & Wang, T. S. (2007). Inhibitory co ntrol and emotion regulation in preschool children. Cognitive Development, 22 (4), 489-510. Davidson, M., Amso, D., Anderson, L. C., & Diamond, A. (2006). Development of cognitive control and executive functions from 4 to 13 years: Evidence from manipulations of memory, inhibition, and task switching. Neuropsychologia, 44 (11), 2037-2078. Davidson, R., Jackson, D. C., & Kalin, N. H. (2000) . Emotion, plasticity, context, and regulation: perspectives from affective neuroscience. Psychological Bulletin, 126 (6), 890-909. Deater-Deckard, K., Petrill, S. A., & Thompson, L. A. (2007). Anger/frustration, task persistence, and conduct problems in childhood: a behavioral gen etic analysis. Journal of Child Psychology and Psychiatry, 48 (1), 80-87. Diamond, A. (2006). The early development of execut ive functions. In E. Bialystock & K. Craik (Eds.), Lifespan cognition: Mechanisms of change (pp. 70-95). Oxford: Oxford University Press. DiCintio, M., & Parkes, J. (1997). The influence of goal orientation on working memory capacity . Paper presented at the American Psychological Assoc iation. Fredrickson, B. L. (2001). The role of positive emo tions in positive psychology: The broaden- and-build theory of positive emotions. American Psychologist, 56 (3), 218-226. Garon, N., Bryson, S. E., & Smith, I. M. (2008). Ex ecutive function in preschoolers: A review using an integrative framework. Psychological Bulletin, 134 (1), 31-60. Gauvain, M. (2001). The social context of cognitive development . 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Westport, CT: Ablex Publishing. Meyer, D. K., & Turner, J. C. (2006). Re-conceptual izing emotion and motivation to learn in classroom contexts. Educational Psychology Review, 18 (4), 377-390. Mizuno, K., Tanaka, M., Fukuda, S., Imai-Matsumura, K., & Watanabe, Y. (2011). Relationship between cognitive function and prevalence of decrea se in intrinsic academic motivation in adolescents. Behav Brain Funct, 7 (4). Network, N. E. C. C. R. (2005). Predicting individu al differences in attention, memory, and planning in first graders from experiences at home, child care, and school. Developmental Psychology, 41, 99-114. Neitzel, C., & Stright, A. D. (2003). Mothers' scaf folding of children's problem solving: establishing a foundation of academic self-regulato ry competence. Journal of Family Psychology, 17 (1), 147-159. Posner, M. I., & Rothbart, M. K. (2000). Developing mechanisms of self-regulation. Development and Psychopathology, 12 (03), 427-441. Pintrich, P. R., & De Groot, E. V. (1990). Motivati onal and self-regulated learning components of classroom academic performance. Journal of Educational Psychology, 82 (1), 33-40. Raaijmakers, M. A. J., Smidts, D. P., Sergeant, J. A., Maassen, G. H., Posthumus, J. A., van Engeland, H., et al. (2008). Executive functions in preschool children with aggressive behavior: Impairments in inhibitory control. Journal of Abnormal Child Psychology, 36 (7), 1097-1107. Risken-Walraven, R., Meij, H., van Roozendaal, J., & Koks, J. (1993). Mastery motivation in toddlers as related to quality of attachment. In D. Messer (Ed.), Mastery motivation in early childhood (pp. 189Œ204).London: Routledge. Rogoff, B., Mistry, J., Goncu, A., & Mosier, C. (19 93). Guided participation in cultural activity by toddlers and caregivers. Monographs of the Society for Research in Child Development, 58 (8), v-179. Ruff, H. A., & Rothbart, M. K. (1996). Attention in early development: Themes and variatio ns . New York: Oxford University Press. Schumacker, R. E., & Lomax, R. G. (2010). A beginner's guide to structural equation modeling (Third ed.). New York, NY: Routledge. Schutz, P. A., & Lanehart, S. L. (2002). Introducti on: Emotions in education. Educational Psychologist, 37 , 67-68. Spangler, G. (1989). Toddlers' everyday experiences as related to preceding mental and emotional disposition and their relationship to sub sequent mental and motivational development: A short-term longitudinal study. International Journal of Behavioral Development, 12 (3), 285-303. Turner, J., Meyer, D. K., & Schweinle, A. (2003). T he importance of emotion in theories of motivation: empirical, methodological, and theoreti cal considerations from a goal theory perspective. International Journal of Educational Research, 39 (4-5), 375-393. Wang, J., & Barrett, K. C. (2013). Mastery motivati on and self-regulation during early childhood. In K. C. Barrett, N. A. Fox, G. A. Morgan & L. A. D aunhauer (Eds.), Handbook of Self- Regulatory Processes in Development: New Directions and International Perspectives (pp. 337). New York: Psychology Press. Wigfield, A., Eccles, J. S., Schiefele, U., & Davis -Lean, P. (2006). Development of achievement motivation. In N. Eisenberg, W. Damon & R. Lerner ( Eds.), Handbook of Child Psychology (6th ed., pp. 933-1002). New York: Wiley. Chapter 4. Conclusions Every day children face different challenges that could lead to new knowledge or skills. Sometimes these new tasks may be easily completed, but other times they may not. When children have to conduct a moderately difficult tas k, some of them refuse to finish it and will give up, but some children continue attempting to a chieve a task-related goal, and thus may gain the benefit of the knowledge or skills afforded by the task. What makes this difference in children™s behavior and related cognitive outcomes? This dissertation considered children™s mastery motivation as a key factor. Mastery motivat ion is defined as an intrinsic force that helps an individual to sustain their attempts to master m oderately challenging tasks or skills (Barrett, Morgan, & Maslin-Cole, 1993). This dissertation con sisted of two studies. The first study (chapter 2) addressed how mastery motivation develo ps and the kinds of factors can improve or hinder the development of mastery motivation during the first three years. The second study (chapter 3) explored how early mastery motivation a ffects children™s later cognitive processes at school-age. The results from both studies within th is dissertation extend current knowledge about the development of mastery motivation and its effec ts of mastery on later cognitive processes. The findings of chapter 2 suggest that early matern al depressive symptoms affect children™s later mastery motivation and related dom ains during the child™s first three years. Furthermore, the results indicated meditational rol es of maternal sensitivity and intrusiveness during the second year. More specifically, in the d irect path model, maternal depression symptoms negatively linked with mastery motivation and related domains including self- regulation and general cognitive skills. However, a direct negative effect of early maternal depressive symptoms on children™s later mastery mot ivation was not significant when considering maternal parenting at 24 months, while the negative effects of early maternal depressive symptoms on children™s later self-regula tion and general cognitive skills were still significant. The negative effects of early maternal depressive symptoms on children™s later mastery motivation were fully mediated via maternal sensitivity, but not maternal intrusiveness. Maternal intrusive behavior may affect different do main of social and cognitive development than does sensitivity. For example, maternal intrus iveness mediated the negative effects of early maternal depressive symptoms on children™s later se lf-regulation and general cognitive skills. These findings imply that mastery motivation is aff ected by positive maternal behavior rather than negative behavior and mastery motivation is a different construct from self-regulation and general cognitive skills. The results of chapter 2 also showed gender differe nces in the effects of maternal depression. Boys whose mothers had more depressive symptoms at 6 months displayed poor general cognitive skills at 36 months. However, mas tery motivation and self-regulation were not predicted by early maternal depressive symptoms dir ectly, but rather, the effect of depression was mediated by maternal sensitivity (Figure 11). F or girls, early maternal depressive symptoms did not have any direct negative effects on later s ocial-cognitive development. Maternal sensitivity mediated the effects of early maternal depressive symptoms on children™s mastery motivation and general cognitive skills for girls ( Figure 12). These findings indicate that boys may be particularly vulnerable to their mothers™ de pressive symptoms. Figure 11. Boys' Conceptual Model. The darker lines indicate relationships identified for boys that were not identified for girls. Figure 12. Girls' Conceptual Model Girls had higher general cognitive skills than boys at 36 months. These results are consistent with previous research in which maternal depression affected boys™, but not girls™ later IQ scores (Milgrom et al., 2004). Thus, the direct and indirect negative effects of early maternal depressive symptoms via maternal behavior identifie d in this study may explain boys™ lower cognitive skills. The findings of chapter 2 suggested the importance of early intervention to decrease maternal depressive symptoms to prevent the negativ e effects of early maternal depression on later children™s social and cognitive skills includ ing mastery motivation, self-regulation, and general cognitive skills. In addition, parenting ed ucation helps depressed mothers to form positive relations with their children. For example , mothers may benefit from interventions that support their use of more sensitive and less intrus ive behavior toward their children at 24 months. In chapter 3, the results indicate the unique role of mastery motivation in the development of executive function skills. As expect ed, children™s mastery motivation at 54 months predicted the development of a set of execut ive function skills including short- and long- term memory abilities and problem-solving skills in the first grade. However, mastery motivation did not mediate the effects of children™s early emo tional regulation abilities on later executive function skills. Instead, mastery motivation predic ted three of the executive function skills, while emotion regulation predicted only one which mastery motivation did not predict. This finding confirmed that mastery motivation and emotional reg ulation are separate constructs, each with a unique role in the development of executive functio n skills. Maternal sensitivity also plays an important role i n the development of children™s executive function skills, especially memory skills . In this study, maternal sensitivity was characterized as less hostility and more emotional support and respect of children™s autonomy. Children who received more sensitive care from moth ers at 36 months showed better memory skills including short-term and long-term memory in the first grade. Children may learn from mothers™ behavior how to encode and use mental info rmation. Early maternal sensitivity moderated the effects of emotional regulation abili ties on the development of executive function skills. Specifically, children with poor emotional regulation abilities showed high levels of impulsive responding later when their mothers were less sensitive at 36 months. In contrast, there was no influence of emotional regulation for childr en who had more sensitive mothers. Children™s early emotional regulation was directly linked with later control of impulsive responding. Earlier experience of successful regula tion of their emotions leads children to better control their behavior later in life. Children can learn some skills or strategies to modulate their emotion. Thus, children with better emotion regulat ion abilities may use these skills more easily, which would allow them to better control their impu lsive behavior. Finally, this study also showed significant interactions of emotion regulati on and maternal sensitivity for the development of long-term memory skills. Children™s emotional regulation enhances the positive effects of early maternal sensitivity on later memo ry skills. These two papers used longitudinal data from a larg e and diverse sample. However, the majority of the mothers and children participating in the study were of European American. Therefore, the generalizability of the results is l imited as results may differ in other ethnic groups . For example, for African-American mothers and child ren in the current sample, early maternal depression directly affected only children™s later general cognitive skills. There were no mediational roles of maternal sensitivity and intru siveness between early maternal depression and children™s later social and cognitive skills. T herefore, future research should compare effects of early maternal depression on children™s later ma stery motivation and related domains in other ethnicities. Also needed is the examination of whet her the role of mastery motivation in later cognitive development differs across ethnicities. T hese future studies would extend knowledge about variation in the development of mastery motiv ation and its effects on later cognitive development across diverse ethnic groups. The study reported in Chapter 2 examined maternal d epressive symptoms at 6 and 24 months. Other studies have emphasized the effects o f chronic maternal depression on maternal parenting and child development (e.g. Campbell, Mat estic, Von Stauffenberg, Mohan, & Kirchner, 2007). Therefore, future studies should e xamine the effects of chronic maternal depressive symptoms across early childhood. Doing so would expand knowledge of the effects of maternal depressive symptoms on the development of mastery motivation. Overall, these two studies extend our current knowl edge about children™s mastery motivation. Mastery motivation is influenced by pos itive maternal behaviors rather than negative behaviors unlike self-regulation and general cognit ive skills and there are no gender differences in the effects of early maternal depression on late r mastery motivation. In addition, mastery motivation improves children™s later executive func tion skills and plays a different role from emotion regulation ability in fostering of children ™s executive function skills. It implies that mastery motivation is a separate and unique constru ct. These two studies contribute to understanding more clearly the relations between ma stery motivation and maternal behavior and the mechanism by which children™s mastery motivatio n affects their cognitive outcomes. REFERENCES REFERENCES Barrett, K. C., Morgan, G. A., & Maslin-Cole, C. (1 993). Three studies on the development of mastery motivation in infancy and toddlerhood. In D . J. Messer (Ed.), Mastery motivation in early childhood: Development, measurement and so cial processes (pp. 83Œ108). London: Routledge. Campbell, S. B., Matestic, P., Von Stauffenberg, C. , Mohan, R., & Kirchner, T. (2007). Trajectories of maternal depressive symptoms, mater nal sensitivity, and children's functioning at school entry. Developmental Psychology; Developmental Psychology, 43 (5), 1202-1215. Karreman, A., van Tuijl, C., van Aken, M. A. G., & Dekovic, M. (2009). Predicting young children's externalizing problems: Interactions amo ng effortful control, parenting, and child gender. Merrill-Palmer Quarterly, 55 (2), 111-134. Vallotton, C., & Ayoub, C. (2011). Use your words: The role of language in the development of toddlers' self-regulation. Early Childhood Research Quarterly, 26 (2), 169-181.