"urn...- u-«owwo.~,-m AN EXPLG‘RATORY STUDY OF THE INTERRELATIONS AMONG ' Dmvme ABILRY, DRIVING, EXPOSURE AND *- SOCIO~ECONOMIC smzrusfior LOW, AVERAGE AND HIGH INTELLIGENCE MALES Thesis for the Segree of .Ed._ D. MicHIGAN STATE UNIVERSITY Robert W. Gutshan 1967 IIIIIIIII IIIIIIIIIIIIIIIIIIIII g 12|93 10714 7559 [.13in R Y MlChlgan Stab niversity This is to certify that the I thesis entitled AN EXPLORATORY STUDY OF THE INTERRELATIONS AMONG DRIVING ABILITY, DRIVING EXPOSURE AND SOCIO-ECONOMIC STATUS OF LOW, AVERAGE AND HIGH INTELLIGENCE MALES presented by Robert W. GutshaII has been accepted towards fulfillment of the requirements for Ed.D. Education Maw Major professor degree in Dan, 2/ I 3/67 0-169 . I ABSTRACT AN EXPLORATORY STUDY OF THE INTERRELATIONS AMONG DRIVING ABILITY, DRIVING EXPOSURE AND SOCIO-ECONOMIC STATUS OF LOW, AVERAGE AND HIGH INTELLIGENCE MALES by Robert W. Gutshall The purpose of this study was to investigate inter— relationships among driving ability, intelligence, socio- economic status and driving exposure of males with low, average and above average 10's. The subjects for this study were selected from former high school students who had attended school between 1960 and 1964, had been issued a Michigan driver's license, and were, at the time of the study, residing within the city limits of Lansing, Michigan. Subjects were assigned to groups on the basis of intelligence scores recorded in their school records. All subjects who were enrolled in the high school special education program for the educable mentally retarded and otherwise qualified for this study on the basis of the criteria listed above, were assigned to the low intelligence group. The socio—economic status of these low intelligence subjects was then determined using demographic census data. Robert W. Gutshall A median socio-economic index was obtained and assignment to the high or low socio-economic group accomplished. The total number of low intelligence subjects was 72, which meant that 36 were assigned to each socio-economic group. Subjects for the average and above average intelli— gence groups were selected at random from the list of pro- spective subjects who satisfied the criteria for selection listed above, including the added dimension of socio-economic status. The total number of subjects in the average and above average groups was 144. Initial attempts to analyze data on the 216 subjects indicated constriction of the data. In an attempt to alleviate this constriction two groups of 108 subjects each were added to the average intelligence groups. All subjects except these added 216 were inter- viewed. Official State of Michigan driving records of the male educable mentally retarded subjects were compared with the driving records of subjects assigned to the average and above average intelligence groups. The interrelationships between intelligence levels, socio-economic status levels, accidents, violations and driving exposure were compared. The original 216 subjects were interviewed to obtain estimates of the number of miles driven per year as well as the number of hours spent in a motor vehicle each day. In addition, information on participation in driver education courses while in high school was obtained by the interviewer. Robert W. Gutshall Analysis of variance was used to determine if signif- icant differences existed between group means. When signif- icance appeared an individual comparison of means using the Newman—Keuls procedure was used. A .10 level of significance was established as the critical value of accepting or reject- ing differences. On the basis of the findings reported in this inves- tigation the following conclusions, concerning the population under study, are made: 1. Intelligence and socio-economic status do not appear to be predictive of number of violations a driver will commit. 2. Intelligence and socio-economic status do not appear to be predictive of number of accidents in which a driver will become involved. 3. Intelligence and socio-economic status do not appear to be predictive of the total number of ”points" which a driver will receive for having committed traffic violations. 4. Intelligence and socio-economic status do not appear to be predictive of the number of miles a person will drive his automobile per year. 5. As a group of drivers educable mentally retarded males have a larger total of combined convictions for traffic violations and involvement in accidents Robert W. Gutshall than groups of male motorists with average intel— ligence scores. It should be noted that an individ- ual's IQ score in and of itself is not necessarily predictive of driving performance. 6. Socio-economic status tends to predict the propor- tion of points a driver will receive for Speeding violations. 7. Intelligence tends to predict the proportion of points a driver will receive for moving violations, other than speeding. 8. Intelligence tends to predict the number of hours a driver will Spend per day in an automobile. These conclusions were discussed and implications for future research were noted. AN EXPLORATORY STUDY OF THE INTERRELATIONS AMONG DRIVING ABILITY, DRIVING EXPOSURE AND SOCIO-ECONOMIC STATUS OF LOW, AVERAGE AND HIGH INTELLIGENCE MALES BY To» Robert W) Gutshall A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of DOCTOR OF EDUCATION Department of Elementary and Special Education 1967 Copyright by ROBERT W; GUTSHALL 1967 ACKNOWLEDGMENTS The investigator expresses appreciation to all those who have been associated with this research. Dr. Donald Burke, chairman of the researcher's doctoral committee, Drs. Walter Freeman, Charles Mange, William Mann and Fred Vescolani have been most helpful in aiding and supporting this project through to completion. The study would not have been possible without the financial aid of the Division of Accident Prevention, United States Department of Health, Education, and Welfare. Valuable consultant services in specialized areas were received from Drs. Walter Freeman, William Mann and Walter Stellwagon. Special appreciation and gratitude must go to Marvin Beekman, Director of Special Education, Lansing Public Schools, whose interest and influence motivated my profes- sional development, thus making it possible for me to work on this project. Acknowledgment is made, also, for the assistance given by former chairmen Drs. Henry Gottwald and Bobby Palk, who were responsible, each in their own way, for the comple- tion of this project. ii Throughout the project all agencies were most cooperative. The Secretary of State: Honorable James M. Hare, Northwestern Traffic Institute, Lansing Police Depart— ment, Michigan State Traffic Center, and the Lansing Board of Education and its related personnel have assisted beyond what one might reasonably expect. No request made to any of these agencies was at any time denied. Appreciation is also expressed to Dr. Charles Harper who has been most helpful, not only in the statistical analysis of the data but also with general suggestions. My wife, Peg, and children: Bobby, Peggy, Kathy, Janie and Sharon, certainly deserve platitudes for their understanding when father was busy. iii TABLE OF CONTENTS ACKNOWLEDGMENTS . . . . . . . . . . . . . . . . . . LIST OF TABLES O O O O O C O O O O O O O O O O O 0 LIST OF APPENDICES . . . . . . . . . . . . . . . . Chapter I. INTRODUCTION . . . . . . . . . . . . . . . II. RE III. ME Definition of Terms . . . . . . . . . LATED RESEARCH . . . . . . . . . . . . . The Relationship Between Physical Coordination and Intelligence . . . . The Relationship Between Driving Ability and Intelligence . . . . . . . . The Relationship Between Driving Ability and Other Selected Factors . . . . . . Summary . . . . . . . . . . . . . . . . . THOD OLOGY O O O O I O O O O O O O O O O 0 Procedures . . . . . . . . Selection of Subjects . Collection of Data . . . . . . . Analysis of Data . . . IV. RESULTS 0 C O O O I O O O O O O O O O O O 0 Driving Ability Data . . . . . . . . . . Driving Exposure Data . . . . . . . . . . Summary of Findings . . . . . . . . . . . V. SUMMARY, DISCUSSION AND RECOMMENDATIONS FOR APPENDICES FUWRE MSEARCH . O O O O O O C C O I I O summary 0 O O O O O O O O O O O O O O O 0 Discussion . . . . . . . . . . . . . . . Recommendations for Future Research . . . BIBLImMPHY O O O O O O O O O O O O O 0 O O O O 0 iv Page ii viii 12 l7 l9 19 20 21 27 31 32 33 50 55 58 58 62 69 75 96 LIST OF TABLES Table Page 1. Classification of factors and the index values assigned to the factors, data determined socio-economic status of all subjects . . . . . . . . . . . . . . . . . . . . 23 2. Subject classification groups . . . . . . . . . 25 3. Mean ages of subjects . . . . . . . . . . . . . 26 4. Mean IQ% of all subject groups according to intelligence levels and socio—economic status . 27 5. Means and standard deviations of the sum of violations and accidents between July 1, 1962 and June 30, 1965 for interviewed subjects compared on intelligence and socio—economic status . . . . . . . . . . . . . . . . . . . . . 34 6. Analysis of variance of sum of violations and accidents between July 1, 1962 and June 30, 1965 for interviewed subjects compared on intelligence and socio-economic status . . . . . . . . . . . . . . . . . . . . . 35 7. Means and standard deviation for the sum of violations and accidents, between July 1, 1962 and June 30, 1965, comparing all subjects grouped according to intelligence level and socio-economic status . . . . . . . . . . . . . 36 8. Analysis of variance for the sum of violations and accidents between July 1, 1962 and June 30, 1965 comparing all subjects grouped according to intelligence level and economic status . . . 37 9. Comparison of means of intelligence groups with socio-economic levels combined for the sum of violations and accidents between July 1, 1962 and June 30, 1965 . . . . . . . . . 38 Table 10. ll. 12. 13. 14. 15. 16. 17. 18. Percentage of subjects involved in viola— tions and accidents, between July 1, 1962 and June 30, 1965, all subjects grouped according to intelligence level and socio- economic status . . . . . . . . . . . . . . Means and standard deviations of viola- tions between July 1, 1962 and June 30, 1965, all subjects . . . . . . . . . . . . . Analysis of variance of violations between July 1, 1962 and June 30, 1965, all subjects Means and standard deviations of accidents between July 1, 1962 and June 30, 1965, all subjects I O O O O O O O I O O O O O O 0 Analysis of variance of accidents between July 1, 1962 and June 30, 1965, all subjects . . . . . . . . . . . . . . . . . . Means and standard deviations of total points accumulated between July 1, 1960 and June 30, 1965 for interviewed subjects compared on intelligence and socio-economic status . . . . . . . . . . . . . . . . . . . Analysis of variance of total points accumulated between July 1, 1960 and June 30, 1965 for interviewed subjects compared on intelligence and socio-economic status . . . . . . . . . . . . . . . . . . . Means and standard deviations of points accumulated for speeding, from July 1, 1960 to June 30, 1965 for interviewed subjects grouped according to intelligence and socio- economic status . . . . . . . . . . . . . . Analysis of variance of points accumulated for speeding, from July 1, 1960 tx) June 30, 1965, for interviewed subjects grouped according to intelligence and socio-economic status . . . . . . . . . . . . . . . . . . . vi Page 39 40 41 41 42 43 44 45 46 Table Page 19. Means and standard deviations for points accumulated for violations other than speeding, between July 1, 1960 and.June 30, 1965, for interviewed subjects compared on intelligence and socio-economic status . . . . 47 20. Analysis of variance for points accumulated for violations other than speeding, between July 1, 1960 and June 30, 1965, for inter- viewed subjects compared on intelligence and socio-economic status . . . . . . . . . . 48 21. Comparison of means of intelligence groups with socio-economic levels combined for points accumulated for violations other than speeding between July 1, 1960 and June 30, 1965 . . . . . . . . . . . . . . . . 49 22. Means and standard deviations of subjects' estimates of miles driven per year, interviewed subjects . . . . . . . . . . . . . 50 23. Means and standard deviations of subjects' estimates of hours a day in a motor vehicle, interviewed subjects . . . . . . . . . . . . . 51 24. Analysis of variance of subjects' estimates of hours a day in a motor vehicle, inter- viewed subjects . . . . . . . . . . . . . . . 52 25. Comparison of means of intelligence groups with socio-economic levels combined for subjects' estimates of hours a day in a motor vehicle . . . . . . . . . . . . . . . . 53 26. Percentage of subjects reporting enrollment in a driver education course . . . . . . . . . 54 vii Appendix A. B. LIST OF APPENDICES Page Request for Michigan Driver Record Information, OC-70 . . . . . . . . . . . 75 Pertinent Basic Data Used in the PrOjeCt O O O O O O O O O O O O O O O O O 76 viii CHAPTER I INTRODUCTION The Lansing Public School system, since 1954, has maintained a high school special education program for the educable mentally retarded student. During the first twelve years of the program over two hundred mentally retarded stu- dents have been provided with individual programs within the specialized curriculum. The students in this program have been encouraged to participate in all school activities in which they could qualify and successfully cope with the requirements. A few of the students were enrolled in regular academic courses. However, satisfactory completion of those courses required special effort not only by the students, but also by the teachers and special education personnel. Most of the students participated in physical education, art and driver education. The philOSOphy of the driver education department was based on the idea that the mentally retarded and the physically handicapped should have the opportunity to partic- ipate in driver education instruction. The driver education staff felt that these eXperiences, both in the classroom and behind the wheel, would help the mentally retarded students to become enlightened pedestrians even if they should not be able to qualify for a license to drive. Even,though high school special education classes for the educable mentally retarded have existed only since 1954, driver education for all Lansing high school students, including slow learners, has been available for students since 1948. ,As the educable mentally retarded were admitted and integrated into the high school program various teaching methods have been used to help them obtain the maximum bene— fits from driver education instruction. Originally the educable mentally retarded students were taught the fundamen— tals of driving by enrollment in driver education classes without supportive assistance from Special education person- nel. However, it proved more satisfactory to modify the foregoing procedure. The first modification was a driver education class consisting only of educable mentally retarded students. The driver education instructor in that case was also certified in Special education. This system did not prove adequate to meet the needs of the educable mentally retarded students and after Several years the system pres— ently in use was developed by driver education and Special education personnel. The special education students were enrolled, in compliance with normal legal restrictions, in the regular driver education class. Their next class was a period where the special education teacher helped the educa- ble mentally retarded student with the preceeding period's assignment. The special education teacher coordinated the post driver education class activities with the regular driver education teacher's lesson plan and in this way clarified any concepts that may not have been correctly understood by the educable mentally retarded student. Often, particularly when a group had a non—reader in attendance, the special education teacher read assignments and examina- tions. With this amount of assistance, many educable men- tally retarded students successfully completed the driver education course and became eligible to take the state driver examination at 16 years of age. Due to the fact that at 18 years of age a Michigan resident is able to obtain a driver's license without ever having been enrolled in driver education, it is imperative that driver education for the educable mentally retarded be included in the special education program. However, the Lansing Public School driver education teachers, Special education teachers and administrative personnel in both departments have some anxiety over the ability of a person with low intelligence to cope with the complexities of modern day traffic. A recent publication of the National Safety Council (1965) presents some indication of the magnitude of the vehicle safety problem today and gives some indication of what one may eXpect in the future. In a recent Six year period (1958-1964), the number of deaths due to automobiles had risen from 36,981 to 47,700. During that period, the number of vehicles had risen from 68.8 million to 87.3 million, while the number of miles these vehicles traveled had risen from 665 billion to 840 billion miles with an increase of from 81.5 to 96 million drivers. Most traffic experts compute the traffic accident problem by using death rates. In the same aforementioned period, the death rate per 10,000 motor vehicles rose from 5.4 to 5.5. For each 100 million vehicle miles driven, the death rate went from 5.6 to 5.7 and per 100,000 population the rate rose from 21.3 to 24.9. The cost of the vehicular accident involve- ments, meanwhile had risen from 5.6 to 8.0 billion dollars. In view of the real concerns of our society in the area of driving safety and the fact that some persons with limited mental ability will be licensed to drive, the Special Education Department of the Lansing Public Schools applied for and received funds from the Department of Health, Education and Welfare to investigate the driving habits of former educable mentally retarded students. This study was designed to determine to what extent intelligence and socio-economic status influenced the driv— ing ability as well as driving habits of former high school students. Specifically, State of Michigan official driving records of educable mentally retarded individuals were compared with the records of individuals who possessed normal and above normal intelligence. The subjects were also compared on socio-economic status as determined by official census records. In addition, subjects were inter— viewed to obtain an estimate of the number of miles driven each year as well as an estimate of the average number of hours spent in a motor vehicle each day. CHAP TER I I RELATED RESEARCH It is generally agreed that the ability to drive an automobile is dependent on many interrelated aspects of human behavior. For a number of years researchers have concerned themselves with investigating the relationship between these variables of human behavior and driving ability. The following review of literature concerns itself with some of the more important studies in several areas, namely: the relationship between physical coordination and intelligence: the relationship between driving ability and intelligence; and the relationship between driving ability and other selected factors. The Relationship Between Physical Coordination and Intelligence Cantor and Stacey (1951), used 175 male mental defec- tives who were residents of the Syracuse State School, New Ybrk to reject the hypothesis that mental defectives had the same manual dexterity as the person with normal intelligence. The chronological ages of the mental defectives were 14-18 years and their IQ scores ranged from 42—87. The controls for the study were 865 male industrial workers and 456 male veterans. They used the Purdue Pegboard Test to test manual dexterity of both the mental defectives and the control group. Results showed that the 52 defectives making the highest IQ scores failed to compare favorably with the man- ual dexterity scores of the control group. However, Cantor and Stacey did observe cases of individual differences where— in a person of low intelligence had the same or equal manual dexterity as that of a person with higher intelligence. Howe (1959), using 43 retarded children who had a mean IQ of 66.0 and an equal number of normal children who had a mean IQ of 98.7, concluded that the retarded group were inferior in a series of motor skill tests consisting of balancing, jumping and strength. Howe, also found cases of individual differences similar to those reported by Cantor (1951). No definite pattern of dexterity was evident for individuals in either intelligence group. Kulcinski (1945), from a sampling of 54 boys and 51 girls, concluded that a positive relationship existed between various degrees of intelligence of fifth and sixth grade boys and girls in the learning of fundamental muscular skills. Boys, used in the sample, had IQ'S ranging from 45-123 while the girls' IQ'S ranged from 43-125. The Relationship Between Driving Ability and Intelligence The literature appeared to have two kinds of arti— cles about the relationship between driving ability and intelligence; namely, statements of eXpert opinion and research studies. The following quotation taken from Brody (1947, p. 6) is an example of the former: Obviously, an idiot cannot be trusted with a car. On the other hand a high degree of intel- ligence does not seem to be essential to the safe and skillful operation of a motor vehicle. Conger, Gaskill, Glad, Hassell, Rainey and Sawrey (1959), used the Information, Comprehension, Similarities and Block Design sub-tests of the Wechsler Adult Intelligence Scale to determine that 10 accident repeaters had a prorated intelligence quotient of 105.3 and the 10 non-accident sub- jects had a mean IQ of 106.3. The differences between the two groups were not significant. Although not specifically investigating the relation- ship between intelligence and driving ability, Levonian, Case and Gregory (1963) were interested in cognitive vari— ables. They tested 720 California truck drivers for: knowl- edge of regulations, form identification Speed and form identification accuracy. They concluded that cognitive variables contributed insignificantly to the variance in recorded accidents. McFarland and Moseley (1954) tested 67 Champion Roadeo truck drivers and found that the drivers' mean IQ score on the Otis Test of Mental Ability was 112. This find- ing is interesting in light of McFarland's and Moseley's (1954, p. 29) comment that: "It is possible to be too intelligent to be successful in some monotonous tasks." Even though an IQ of 112 is slightly above average such a score would classify a person in a higher category than 83% of the general population. It should be noted that less intelligent contestants may have been eliminated before they reached the Roadeo finals. McGuire (1955), from a total of 446 military service subjects, selected 67 accident-violation free and 67 accident— violation personnel for his research. On a group basis, using the Army General Classification Test (civilian version), he found means of 108.7 for the accident-violation free group and 109.2 for the accident-violation subjects. The critical ratio for the differences between the means, was not significant. The researchers engaged in the Eno Study (1948) did not use a standard measure of intelligence, but they did deve10p a "Knowledge Test for Automobile Drivers." Using that tool and 20 questions covering motor vehicle regulations and rules of the road they tested the accident and the acci— dent—free groups, to find that the accident—free drivers had 10 significantly better test scores than those drivers with records of accidents. Goldstein (1962) indicated little correlation exist- ing between driving ability and cognitive measures in 14 studies he reviewed. His conclusion, as far as human vari— ables are concerned, was that accidents are largely a func- tion of age, alcohol and attitudes. Hakkinen (1958, p. 54) stated after his review of accident studies in EurOpe and America, that: "it has been proven quite convincingly that the drivers who are consider- ably below the average in intelligence are prone to acci- dents.“ Hakkinen (1958, p. 78) further stated that: "as a general rule, accidents do not appear to be due to ignorance of traffic rules or of other things related to driving skill." The instruments he used in his research on 140 commercial drivers were a variation of the KOh's Block Design, the Pathtracing Test, and a Mechanical Comprehension Test sim- ilar to the Bennett Mechanical Comprehension Test. He did not find Significant differences between the safe and acci- dent groups in these intelligence and mechanical aptitude tests. However, he concluded that accidents Show a slight tendency to increase as intelligence declines. It should be noted that on a preselected population, such as commercial drivers, one might eXpect not to find differences in intel- ligence. 11 Selling (1941) examined 500 referrals from the Traffic Division of the PsychOpathic Clinic of the Recorders Court in Detroit and concluded that individuals with intel- ligence scores below 70 had more violations than a compara- ble grouping above that figure. Of the violators he tested at the clinic, 36%.received an IQ score below 70. However, there was an obvious unreported selection factor which shOUld probably be considered in evaluating the results, i.e., only certain offenders were selected by the judges to attend the clinic. Brown and Ghiselli (1947) for a sample of 247 motor- men found that a high score on an intelligence test had no validity for helping to predict a driver's accident eXperi— ence as a motor coach Operator. Baker (1952) while Director of Research and Develop- ment for the Northwestern Traffic Institute indicated that a high grade moron with a mental age of 10 or 12 years, who is not easily distracted, is better equipped to handle an auto than smarter people. Baker stated: . . . the Operation of a motor car is too dumb a job to command the attention of those who are particularly bright. The low mentality motorist once he is taught to drive properly, will not deviate from what he has learned. The higher mentality is inclined to experiment and also to think about things to the detriment of his driving. 12 Gutshall (1963) reported on 200 educable mentally retarded driver education students and found that the young- sters could function in driver education classes. Their violation experiences on the road did not appear much differ- ent from the normal students. His conclusions were based on observations of student attendance at a traffic safety school and also his eXperienceS of teaching mentally retard- ed students in driver education classes. Pappanikou and Bowman (1959, 1960) working with 5 girls and 11 boys at Pineland Hospital and Training Center, Pownal, Maine found some success in driver education for their patients. They screened the patients carefully and unless the person had an IQ of 70 with a verbal IQ of at least 60 on the Wechsler Intelligence Scale they were re- jected for driver education. Also, they were required to have had a grade level of 4.0 on the California Achievement Test, Elementary Level. However, of the 16 students only one had received a drivers license at the time of the authors' report. The Relationship Between Driving Ability and Other Selected Factors Brody (1947) studied 26 drivers with a record of at least three reported accidents in a five year period, and a similar number of individuals whose driving records were virtually unmarred. The results on the Bell Adjustment 13 Inventory indicated that personality maladjustment was found to be much more common among the accident-repeaters tested, than among the accident-free. Brody (1947), after using psychological testing, also noted that observance of traffic obligations depended upon personal attitudes rather than motor skills of individual drivers. Case, Reiter, Feblowicz and Stewart (1956) inter- viewed 300 Los Angeles multiple driving violators for the purpose of identifying primary personality characteristics. They concluded that 58.3% were normal in personality; 22% were classified aggressive; 17.3%.were classified as con- formists: 1.7%,were considered as being hostile and the remaining .7% were placed in an undetermined category. The authors observed that the prototype of the habitual traffic- violator is that of a white male, between the ages of 21 and 25, employed in a semiskilled or skilled job, of normal intelligence and a normal personality. The study did not consider personality characteristics of non-violators. Conger g; 31. (1959) matched 10 U.S. airmen who had two or more accidents with 10 U.S. airmen who had no reported accidents. Both a structured interview and a routine psycho- logical examination were administered to the subjects. The psychological examination battery included the following: the Thematic Apperception Test (10 cards), the Rorschach Test, the wechsler-Bellevue Intelligence Scale (4 sub-tests) and the Sacks Sentence Completion Test. The examiners 14 stated that the accident-subjects had a tendency to have less capacity for controlling hostility; were either exces- sively self-centered and indifferent to the rights of others or unduly concerned about the rights and feelings of others; were preoccupied with fantasy satisfactions or extremely stimulus bound; were fearful of loss of love and emotional support; and were less able to tolerate tension without dis— charging it immediately. The Eno Study (1948) compared 252 accident—repeaters with a group of 261 accident-free drivers from the states of Connecticut and Michigan. Results of the Cornell Word Form Test indicated that accident—repeaters tended to have more personality maladjustments than the accident-free and that the incidence of these maladjustments tended to increase among the more serious repeaters. McGuire (1955) employed the Minnesota Multiphasic Personality Inventory, the Bell Adjustment Inventory, the Kuder Preference Record-Personal and the Rosenzweig Picture Frustration Study to study 67 accident-violation free sub- jects and a matched group of accident-violation subjects. He concluded that the accident-free driver had more respect for the law, was more aware of his responsibilities on the highway, had a more tranquil childhood, got along better in school, had a more harmonious family life, saw himself as being easier to talk to, was more willing to present himself 15 before people, and was a serious minded individual who was willing to accept responsibility and make decisions. Moffie, Symmes and Milton (1952) employed the Bernreuter Personality Inventory to perform research on tractor-trailer drivers. They concluded that 30 accident- free drivers had a significant tendency to be more tense, less self-sufficient and less dominant than 30 accident drivers. The California study (Penn, 1965) involved a sample of 1,382 drivers to find factors which were useful in dis- criminating a group of bad drivers from a total driving population. Three variables characteristic of bad drivers were, persons who were unmarried, unsatisfactory credit rating and records of frequent job and address changes. The Eno Study (1948) did not indicate significant differences in the socio-economic status of the accident- repeaters and accident—free. However, more accident-repeat- ers than accident-free persons had been arrested on charges other than traffic. Harvard Medical School (1961-62) reported, on the basis of case histories, that in traffic accidents the driver who caused the accident was the one most likely to have had a record of conflict or poor social adjustment. They also noted that these problems were often a matter of public record. 16 McGuire (1955) used the Minnesota Multiphasic Person- ality Inventory, Kuder Preference Record-Personal, Bell Adjustment Inventory and a personal interview to obtain data on 67 accident-violation free servicemen and an equal group of unmatched accident-violation subjects. He determined that the accident and violation-free driver was more mature, more intellectual in his interests and tastes, had a higher aspiration level, tended to have a more satisfying family life, was more aware of responsibilities when driving, had a more stable approach to people and problems, was more communicative and showed a more diverse and mature kind of interest. One statement he made seems worthy of note be— cause it summarized the general review of literature in this particular area quite well. McGuire (1955, p. 9) stated ". . . driving is an interpersonal situation and it is expected that drivers who get along best on the highway get along best with people." One group of studies which did not fit into the categories already mentioned were those compiled by the Personnel Research Section of the U.S. Army Adjutant Gen- eral's Office (1943). They concluded on the basis of a summary of 40 studies that road tests of driving skill were more reliable indicators for selection of truck drivers than multiple choice tests, previous eXperienceS, and tests of visual and sensori-motor functions, including reaction time. 17 §11m_me£1 This review of related research failed to discover any single cause of accidents or violations. The review of the literature instead indicated that many factors were involved in determining whether a person was a safe driver. Psychomotor functions did not appear to be one of these factors. But, it was noted that physical coordination may be affected for persons who had received IQ scores below 70. However, an IQ score of 70 was not considered a dis- crete point in determining a person's lack of normal phys— ical coordination. Rather, a 70 IQ score was a group statis— tical designation as some individuals below 70 IQ possessed physical motor skills equal to persons of higher intelli- gence. It may be that a mentally retarded person's driving record might be a reflection of his physical coordination rather than his personality and social life. However, the review of related research gave no indication that physical coordination was a factor in determining a person's ability to drive. Intelligence did not appear as a significant factor in determining a driver's violation or accident record. But, some of the researchers stated their belief that it was an influence affecting a person's driving record. When drivers who had been in car accidents or who had committed driving infractions were studied, it was 18 generally found that a driver's personality characteristics and social behavior were significantly different from those of control subjects. The driver's method of facing life issues evidently had a predispositional effect on his driv- ing manners. It is interesting to note that according to one group of studies as reported by the Personnel Research Section of the U.S. Army Adjutant General's Office (1943) the most reliable predictor of driving ability was observing driver behavior during road tests. It is the writer's impression from the review of the literature that researchers had a difficult time obtaining subjects for study. The problem was generally solved by using some type of captive group. These groups usually were traffic violators, fleet vehicle operators, servicemen, fac— tory workers, hOSpital patients, or children in a school. It is evident that techniques used in interpreting the data were not uniform. For example, violators do not necessarily drive the same number of miles, the same time of day nor do they encounter the same degree of law enforcement. CHAPTER I I I METHODOLOGY Definition of Terms Intelligence as used in this study is operationally defined by English and English (1961, p. 268): That hypothetical construct which is mea— sured by a properly standardized intelligence test. . . . Three concepts recur frequently in attempts to state its connotations: That of ability to deal effectively with tasks involving abstractions; that of ability to learn; and that of ability to deal with new situations. The various levels of intelligence and corresponding IQ scores used in this study were: low intelligence (IQ 50-86); average intelligence (IQ 90-110); high intelligence (IQ over 110). Socio-economic status refers to the relative posi— tion of a subject within the groups based on demographic data drawn by Bellamy (1963) from the 1960 U.S. census. Driving ability refers to a driver's record of accidents, violations and points as recorded on an official Michigan driving record form (Appendix A). Violations are driving infractions for which points were issued under the State of Michigan Conviction "Point" 19 20 system described by the Michigan Vehicle Code (1961). Violations in this study were divided into two categories: speeding and other violations. Driving eXposure refers to a subject's estimate of the number of hours Spent in a car and the number of miles driven by him. Procedures The present study, using a sample of low intelli- gence male drivers matched with other drivers selected from the general driving population, was designed to investigate interrelationships among driving ability, intelligence, socio-economic status and driving eXposure, all rigidly defined. The design of this project called for an equal num— ber of subjects in each of three intellectual categories, also equally divided on the basis of high and low socio- economic status. Consequently, six groups of subjects were needed to accomplish this investigation. The following sections describe the procedures in the selection of subjects, data collection, and analysis of data. 21 Selection of Subjects Permission was given by the Lansing Board of Educa- tion, Lansing, Michigan to use the school records of former high school students for the purpose of obtaining the names of males who were mentally retarded, of average intelligence, or of above average intelligence. This search produced the names of 163 male students who had participated in the spe- cial education program for the educable mentally retarded of the Lansing Public Schools and graduated or dropped from school during the school years 1960-1964. The individuals whose names were obtained in this fashion became potential subjects in the low intelligence classification of the study. School records were examined to obtain individual and group IQ scores for assignment to an apprOpriate intel- lectual group. In cases where more than one IQ score was available, the average of the scores was used. Those indi— viduals whose record indicated medical diagnosis of brain damage were excluded from the sample. The procedures of the psychological testing program in the Lansing Public Schools insure that all individual tests, which were used in obtaining an IQ score for the low intelligence subjects, are administered by a state approved school psychologist. Group tests, which were used in obtain- ing IQ scores for subjects of average and above average intelligence, were in all cases forms of the California Test of Mental Maturity. 22 The design of the study demanded differentiation of subjects on the basis of socio-economic status. One method of determining socio-economic status of an individual is to use current census tract data. This method was used in this study and required the investigator to rate an individual's dwelling place on different socio—economic factors. The factors used in this study, based on 1960 census tract data compiled by Bellamy (1963) were: housing deterioration and dilapidation, non-white population, over-crowded housing, property value, unemployment, juvenile crimes, and median family income. Each of the seven factors may be categorized into different levels within each factor. Each level was as- signed a numerical value, with lower numbers representing more favorable conditions. In this study the sum of the seven levels is called the index value. An individual with a lower index value would be considered to be in the more favorable socio-economic Situation. The classification of factors and index values assigned to each factor are listed in Table 1. Once the potential male subjects for the low intel- ligence groups were identified it was possible to select potential male subjects for the average and high intelli- gence groups from the school records of the three Lansing high schools. Subjects of average and above average 23 Table 1. Classification of factors and the index values assigned to the factors, data determined socio- economic status of all subjects Non—White Population Median Family Income Index Index (Classification) Value (Classification) Value 6r% 5 $5,400—$4,300 4 41-60% 4 $7,400—$5,500 3 21-40% 3 $8,400-$7,500 2 1-20% 2 $8,500+ 1 Housing Deterioration and Unemplgyment Dilapidation: City of Index Lansing (Classification) Value Index 8%+ 4 (Classification) Value 6-7% 3 60% or over 4 4-5% 2 40-59% 3 0-3% 1 20-39% 2 0-19% 1 Average Property Value Index Over-Crowded Housing (Classification) Value Index $ 6,000 or below 3 (Classification) Value $12,000-$7,000 2 3h% 4 $13,000+ 1 21-30% 3 11-20% 2 Juvenile Crimes 1953—1956 0—10% 1 , Index (Classification) Value Areas of high violation density 2 2 violations 1 intellectual ability were chosen utilizing a random selec- tion process. An effort was made to match all groups accord- ing to year of graduation and socio-economic classifications. This method of random selection did not provide enough names for subjects who qualified for the above average intelli- gence groups. The investigator was supplied with the 24 National Honor Society membership lists, and names selected at random, were added to insure a minimum number of subjects at the time of final selection. Once it had been determined that enough potential subjects existed, the final selection process was initiated. The design of the study required all of the subjects to be residents within the city limits of Lansing, Michigan and that they be licensed drivers. This information was deter- mined through a personal interview with the potential sub— ject. These interviews produced 72 educable mentally retard- ed male subjects. The method of determining socio—economic status described above was employed by determining a median score for the low intelligence subjects. This procedure resulted in assigning those subjects with an index value of 10 or less in the high socio-economic status group. Those sub— jects with an index value of 11 or more were assigned to the low socio-economic group. The same median value was used in establishing the other groups required by the design. In formulating this study a larger number of sub- jects in the low intelligence group was estimated than could be obtained. To compensate for this shortage it was decided to add two groups of average intelligence subjects, one for each socio-economic group. The total number of added male subjects who were selected at random from driver education 25 records, was 216 allowing 108 for each socio-economic group. These added subjects'were not interviewed because of the limited time of the interviewers. However, each of the 216 added male subjects were determined to be presently residing in the city limits of Lansing, Michigan. This conclusion was made on the basis of current directories and in case of doubt by a personal telephone call. The final composition of the groups used in this study is summarized in Table 2. Table 2. Subject classification groups Group 1: Classified as low intelligence, 36 subjects that had an IQ below 86 with high socio-economic status, interviewed. Group 2: Classified as average intelligence, 36 subjects that had an IQ from 90 to 110 with high socio- economic status, interviewed. Group 3: Classified as high intelligence, 36 subjects that had an IQ above 110 with high socio-economic status, interviewed. Group 4: Classified as average intelligence (not inter— viewed), 108 subjects that had an IQ from 90 to 110 with high socio-economic status. Group 5: Classified as low intelligence, 36 subjects that had an IQ below 86 with low socio-economic status, interviewed. Group 6: Classified as average intelligence, 36 subjects that had an IQ from 90 to 110 with low socio- economic status, interviewed. Group 7: Classified as high intelligence, 36 subjects that had an IQ above 110 with low socio-economic status, interviewed. Group 8: Classified as average intelligence (not inter— viewed), 108 subjects that had an IQ from 90 to 110 with low socio-economic status. 26 Two group characteristics of importance in describ- ing the subjects were age and intelligence. Values for these characteristics are contained in Tables 3 and 4. Table 3 summarizes the information on ages of the subject. Table 3. Mean ages of subjects Intelligence Socio- Average Average (Not Economic Low (Interviewed) High Interviewed) Total High 21.72 20.81 20.39 20.94 20.96 Low 21.39 21.94 21.00 20.93 21.18 Combined 21.55* 21.37* 20.69* 20.94** 21.07 *N = 72. It should be noted that the grand mean is 21.07 years of age and that the subjects of low intelligence had the highest mean age of 21.55. This is not unexpected since members of the low intelligence group more frequently repeat a grade level than the average and high intelligence stu- dents. Table 4 contains the summarization of the mean IQ scores of the subjects. 27 Table 4. Mean IQ's of all subject groups according to intelligence levels and socio-econOmic status Intelligence Socio-Economic Average Average (Not Status Low (Interviewed) High Interviewed) High 73.25 102.33 119.55 101.56 Low 74.38 101.27 118.72 100.23 Combined 73.81* 101.80* 119.13* 100.89** *N = 72. **N = 216. Collection of Data The design of this research required that data be collected from two separate sources. The subject's estimate of their driving eXposure was to be determined through a personal interview, while driving ability was to be inter- preted from official Michigan driving records. Driving exposure.--Subjects in the original six groups of the study were interviewed to obtain information regarding their estimate of the amount of time spent in a motor vehicle and the number of miles the subject drove per year. The information obtained on these two factors was interpreted as driving eXposure. The interviews were completed by three Lansing Public School special education teachers and two school 28 nurses. These were personnel who were familiar with the kind of people to be interviewed. Their routine profession- al duties put them in daily contact with such people and it was felt they could put the interviewees at ease and would have little difficulty in establishing the rapport necessary to obtain an accurate accounting of the requested data. The interviewers were trained by two group meetings as to what information was needed and methods of obtaining the informa- tion were discussed. Their pay was on the basis of each interview completed. Three interviews could not be com— pleted because of a subject's refusal to cooperate. The first question the interviewers asked in deter— mining driving eXposure was: "How many miles do you drive a year?" The interviewers were free to help the subjects arrive at an estimate by asking the subject how many miles were on the odometer when the car was bought, how long had he owned the car and what was the present mileage reading. This procedure was repeated if the subject drove cars other than his own. All tabulations of this data were performed in the presence of the subject. The second question was concerned with the amount of time each subject spent in an automobile. The interviewers asked the subject: "How many hours a day are you in the car? (total time)" The answers were recorded according to one hour or less, 2 hours or less, 8 hours or less and others. In addition to the information on driving exPosure 29 the interviewers were requested to obtain data on each subject's enrollment in a driver education class. Driving ability.--Once the subjects had been selected an official driving record request was obtained from the Michigan Secretary of State's office (Appendix A). The fact that the Michigan Motor Vehicle Code (1961, p. 69) requires reporting of accidents only if there is one hundred or more dollars damage, injury or death, would be a constricting factor in this research except the Lansing Traffic Code (1958, p. 419) states: The driver of a vehicle involved in an acci- dent resulting in injury or death of any person or prOperty damage, shall immediately by the quickest means of communication give notice of such accident to the police department if such accident occurs within this city. These two laws tended to diminish the reporting deficiencies commonly found in research using officialstate records as the criterion for driving ability. However, Since it was assumed that, even with an efficient and reli- able police department some accidents occurred which were not reported, the accident data was undoubtedly an under- estimation of the actual occurrences. Citations reported were only a minute number of all violations occurring. Most violations were not observed by a traffic officer. However, the Lansing Police Traffic Division enforcement procedures consistently result in an 3O enforcement index1 of .30. While unreported violations undoubtedly occurred, the city of Lansing has a higher citation rate than is commonly found in most cities. The study has been confined to persons residing in the Lansing city limits in order to take advantage of this enforcement factor. Accidents and violation reports were obtained from the Secretary of State and may include occurrences outside of the city of Lansing or the state of Michigan. The thoroughness of these reports cannot be considered as reli- able as the violation eXperience in the city, and are very definitely an under-estimate of actual occurrences. June 30, 1965 was used as the terminal date for accepting driving record data. In the case for comparing three year driving records, July 1, 1962 was the beginning date and for computing five year driving records, July 1, 1960 was the beginning date. Information obtained from Form OC-70 as well as information obtained by the interviewers was transferred from the original records to a large work sheet. The trans- fer of information was performed by one secretary in order 1The sum of the number of convictions with penalty obtained for the moving violations listed plus any other hazardous moving violations, divided by the sum of the num- ber of personal injury and fatal accidents in a city over a corresponding period, indicates the enforcement index.(from an official record of Lansing Police Department). 31 to control uniformity of procedures and interpretation. For the statistical data that was computer analyzed the same secretary used the large sheet to punch IBM cards. She also used a verifier to insure data accuracy. Analysis of Data An IBM 1620 computer was used to process the punched cards to perform the statistical analysis. Computer programs were written in Fortran to specifically handle the analyses herein described. Analysis of variance was used to determine if signif- icant differences existed between group means. When signif- icance appeared, the procedure was to follow the overall analysis with an individual comparison of pairs of means using the Newman-Keuls procedure as outlined by Winer (1962). Fmax tests (Winer, 1962) were used to determine that the assumption of homogeneity of variance was met. At the onset a .10 level of significance was established as the critical value of accepting or rejecting differences. Tabled values that determined significance were obtained from Scheffe' (1959). CHAPTER IV RESULTS This investigation was undertaken to eXplore the interrelationships of intelligence, driving ability, socio- economic status and driving exposure of former male high school students. Driving ability was evaluated by using the number of accidents and violations as well as points recorded. This information, on each subject, was obtained from the Michigan Secretary of State's OC-70 Form. Driving exposure was determined during interviews and represents each subject's estimate of miles drivenper year and hours spent in a motor vehicle per day. The information in this chapter follows a format of first presenting the means and standard deviations of sub- ject groups compared, then, an overall analysis of variance to determine if any differences existed between all means. In the cases where the analysis of variance indicated Signif- icant differences, an appropriate individual comparisons of group means followed. All such comparisons were treated using an Fmax statistic and met the assumption of homogene- ity of variance at the .01 level. Several comparisons of 32 33 groups which did not show significant differences, as well as significant comparisons, are included as reference points and to aid in interpretation of the data. All tables are recorded following a format of intelligence levels in columns and socio-economic status in rows. Compared first are the driving records of the subjects. These comparisons are followed by an analysis of the subjects' estimates of driving exposure, subjects' estimate of hours Spent in a motor vehicle, and subjects' reported enrollment in a driver education class. Driving Ability Data Subjects were selected on the basis of measured intellectual ability and their classification grouping of socio—economic status. The information on accidents, traf- fic violations and points accumulated for driving infrac- tions, by each subject, was obtained from the Secretary of State's office and was used as the criteria of driving ability. Numerical values of the driving abilities were grouped according to intellectual levels and socio-economic status for the statistical analysis. The first comparison was of the sum of violations and accidents for the groups between July 1, 1962 and June 30, 1965. This analysis was limited to one-half of the subjects, those 216 who were interviewed. Means for the groups were determined and these 34 means together with standard deviations for the groups appear in Table 5. Table 5. Means and standard deviations of the sum of violations and accidents between July 1, 1962 and June 30, 1965 interviewed subjects compared on intelligence and socio-economic status Socio- Intelligence Economic Status Low Average High Total M 4.75* M 3.80* M 3.86*. M 4.13 High SD 3.70 SD 2.72 SD 3.75 SD 3.45 M 4.30* M 3.19* M 3.44* M 3.64 Low SD 4.35 SD 2.79 SD 3.99 SD 3.80 M 4.52 M 3.50 M 3.65 M 3.89** Combined SD 4.04 SD 2.77 SD 3.88 SD 3.64 *N = 36. **N = 216. Analysis of Table 5.--Inspection of the means of Table 5 revealed that the low intelligence group had the poorest driving record. The average intelligence group had the best driving record. Comparison of socio-economic groups suggested a better driving record for the low socio- economic status groups at all levels of intelligence. To determine if the means of the groups differed significantly an analysis of variance using a 2 x 3 design with an equal 35 number of subjects per cell (Winer, 1962) was made. Table 6 records the results of the analysis of variance. Table 6. Analysis of variance of sum of violations and accidents between July 1, 1962 and June 30, 1965 interviewed subjects compared on intelligence and socio—economic status Source df MS F Socio-economic l 13.00 .97 Intelligence 2 22.14 1.65 Soc.-econ. x intel. 2 .19 .01 Within 210 13.36 ... F .10 (2,°<9 = 2.30. Analysis of Table 6.--Although inspection of the means for intelligence and socio-economic status appeared to indicate differences in Table 5, the analysis of variance in Table 6 showed that those differences that appeared in Table 5 were not significant. The large differences in the means of the groups in Table 5 contrasted with the F value (1.65) for intelligence suggested that the analysis was restricted due to a limited number of subjects. To counterbalance this restriction, the number of subjects was doubled by adding the driving records of two groups of subjects who were not interviewed thereby making the total number of subjects 432. Of the two groups added one group was of high and one group 36 was of low socio-economic status. All added subjects had scores of average intelligence. Means and standard devia- tions for the added subjects and the original interviewed subjects, were recorded for inspection in Table 7. Table 7. Means and standard deviation for the sum of viola- tions and accidents, between July 1, 1962 and June 30, 1965, comparing all subjects grouped according to intelligence level and socio—economic status Intelligence Socio- Economic .Average (Not Status Low Average High Interviewed) Total M 4.75* M 3.80* M 3.86* M 3.16** M 3.65 High SD 3.70 SD 2.72 .SD 3.75 SD 3.26 SD 3.39 M 4.30* M 3.19* M 3.44* M 3.18** M 3.41 Low SD 4.35 SD 2.79 SD 3.99 SD 3.29 SD 3.56 M 4.52 M 3.50 M 3.65 M 3.17 M 3.53*** Combined SD 4.04 SD 2.77 SD 3.88 SD 3.27 SD 3.48 *N = 36. **N = 108. ***N = 432. Analysis of Table 7.--Inspection of Table 7 appeared to duplicate the trend of Table 5. The low intelligence level group had the highest mean of violations and accidents. The means of the two added groups were lower than the means of the low and high intelligence level groups. However, the added group means were nearly equal to the mean of the group 37 of average intelligence level of low socio-economic status. To determine if significant differences existed, comparison of the group means in Table 7 was made by analysis of vari- ance. The design was a 2 x 4 with unequal cell frequencies (Winer, 1962). The results of analysis of variance for the sum of violations and accidents were recorded in Table 8. Table 8. Analysis of variance for the sum of violations and accidents between July 1, 1962 and June 30, 1965 comparing all subjects grouped according to intelligence level and economic status Source df MS F Socio-economic l 8.30 .69 Intelligence 3 27.92 2.33* Soc.-econ x intel. 3 2.61 .22 Within 424 12.05 ... *P < .10. Analysis of Table 8.--The F ratio for intelligence was 2.33 and exceeded the .10 level of significance of 2.08. Because of this significance the means of the intelligence groups with combined socio-economic levels were arranged in ascending order and compared using the Newman-Keuha method. A summary of the comparison is contained in Table 9. 38 Table 9. Comparison of means of intelligence groups with socio-economic levels combined for the sum of violations and accidents between July 1, 1962 and June 30, 1965 Intelligence Average (Not Level Interviewed) Average High Low Means 3.17 3.50 3.65 4.52 Average (Not interviewed) 3.17 .... .33 .48 1.35 Average 3.50 .... ..15 1.02 High 3.65 .... .87 Low 4.52 .... A schematic summarygof Table 9 is as follows.-- Average (Not Interviewed) Average High Low Treatments underlined by a common line (Average Not Inter- viewed-Average, Average-High, High-Low) do not differ; treatments not underlined by a common line (Average Not Interviewed-Low) do differ at the .10 level of significance. The means in Table 7 enabled comparison to be made of the driving ability of different groups. This procedure, however, did not give an indication of whether the signif- icant differences of the means were due to a higher percent- age of subjects being involved in citations and accidents or a higher frequency for individual subjects. In an attempt to determine the reasons for the differences, the prOportion of subjects involved in violations and accidents was compared. 39 Table 10 Shows the percentage of subjects in each group that were involved in violations and accidents for the three year period. Table 10. Percentage of subjects involved in violations and accidents, between July 1, 1962 and June 30, 1965, all subjects grouped according to intelligence level and socio-economic status Intelligence Socio- Economic Average (Not Status Low Average High Interviewed) Total High 86.1T%* 91.67%* 77.78%* 81.48%** 84.26% Low 77.78%* 80.56%* 77.78%* 80.58%** 79.17% Combined 81.92% 86.1T% 77.78%. 81.02% 81.7T%*** *N = 36. **N = 108. ***N = 432. Analysis of Table 10.--Percentages of subjects involved in violations and accidents appeared in a small range of 13.89%. Since a disproportionate number of subjects was not observed in any group the differences between groups could have been due to the frequencies in which the offending subjects received citations and accidents. The criterion of driving ability that had appeared to be significant in Table 8 had been composed of both 40 violations and accidents. To determine if one of these factors was responsible for the differences obtained, a further comparison was made of violations and accidents. Each of these two factors was analyzed independently by an analysis of variance which produced no significant differ- ences. The means and standard deviations for these factors were included in Tables 11 and 13. Table 11. Means and standard deviations of violations between July 1, 1962 and June 30, 1965, all subjects Intelligence Socio- Economic Average (Not Status Low Average High Interviewed) Total M 3.75* M 3.02* M 3.02* M 2.37** M 2.81 High SD 3.04 SD 2.24 SD 3.41 SD 2.69 SD 2.86 M 3.30* M 2.36* M 2.63* M 2.43** M 2.60 Low SD 3.23 SD 2.17 SD 3.36 SD 2.67 SD 2.84 M 3.52 M 2.69 M 2.83 M 2.40 M 2.71*** Combined SD 3.14 SD 2.23 SD 3.39 SD 2.68 SD 2.85 *N = 36. **N = 108. ***N = 432. 41 Table 12. Analysis of variance of violations between July 1, 1962 and June 30, 1965, all subjects Source df MS F Socio-economic l 6.83 .84 Intelligence 3 1.97 .24 Soc.-econ. x intel. 3 1.94 .24 Within 424 8.12 ... II N o \l H F .10 (lfiND) F .10 (3,°<3) = 2.08. Table 13. Means and standard deviations of accidents between July 1, 1962 and June 30, 1965, all subjects Intelligence Socio- Economic Average (Not Status Low Average High Interviewed) Total M .97* M .77* M .80* M .81** M .83 High SD 1.16 SD .85 SD 1.15 SD .97 SD 1.02 M 1.00* M .83* M .80* M .75** M .81 Low SD 1.35 SD .92 SD 1.07 SD .98 SD 1.06 M .98 M .80 M .80 M .78 M .82*** Combined SD 1.26 SD .89 SD 1.11 SD .97 SD 1.04 *N = 36. **N = 108. ***N = 432. 42 Table 14. Analysis of variance of accidents between July 1, 1962 and June 30, 1965, all subjects Source df MS F Socio-economic l .01 .01 Intelligence 3 .80 .73 Soc.-econ x intel. 3 .06 .05 Within 424 1.10 ... F .10 (lfrO) = 2.71. F .10 (Bf‘b) = 2.08. Analysis of Tables 11, 12, 13 and l4.--The pattern for total means of Tables 11 and 13 indicated that for viola- tions and accidents the low intelligence level had the high- est means and that the average intelligence level had the lowest means. However, Tables 12 and 14 indicate no signif- icant differences in group means for either violations or accidents. The information summarized in Tables 11 through 14 indicates that accidents and violations do not appear to be influenced by a person's intelligence or socio-economic status. Another criterion that was used in determining driv- ing ability was the points assigned to a violation according to the Michigan Vehicle Code. Total points accumulated 43 between July 1, 1960 and June 30, 1965 were compared for the interviewed subjects and these means and standard deviations are recorded in Table 15. Table 15. Means and standard deviations of total points accumulated between July 1, 1960 and June 30, 1965 for interviewed subjects compared on intelligence and socio-economic status Socio- Intelligence Economic Status Low Average High Total M 12.27* M 10.83* M 10.47* M 11.19 High SD 8.62 SD 7.10 SD 11.61 SD 9.33 M 11.63* M 8.88* M 7.69* M 9.40 Low SD 10.79 SD 9.58 SD 8.85 SD 9.91 M 11.95 M 9.86 M 9.08 M 10.30** Combined SD 9.77 SD 8.48 SD 10.42 SD 9.67 *N = 36. **N = 216. Analysis of Table 15.--The means in Table 15 had mixed trends with higher means for high socio-economic status and also higher means for the low intelligence level. An analysis of variance with a 2 x 3 design with equal cell frequencies was performed and its result recorded in Table 16. 44 Table 16. Analysis of variance of total points accumulated between July 1, 1960 and June 30, 1965 for inter- viewed subjects compared on intelligence and socio-economic status Source df MS F Socio-economic 1 172.44 1.84 Intelligence 2 159.22 1.69 Soc.-econ. x intel. 2 20.92 .22 Within 210 93.67 .... F .10 (lfxs) = 2.71. F .10 (2,43) = 2.30. Analysis of Table l6.--Table 16 compared group means of total points accumulated for the five year period and revealed no significant differences for either the socio- economic factor or the levels of intelligence. However, a breakdown of the total points into two groups: points accumulated for Speeding and points accumu- lated for violations other than Speeding were analyzed to see if they produced different results. These two groups were analyzed separately and Table 17 records means and standard deviations for points accumulated for speeding for the five year period. 45 Table 17. Means and standard deviations of points accumu- lated for speeding, from July 1, 1960 to June 30, 1965, for interviewed subjects grouped according to intelligence and socio-economic status Intelligence Socio— Economic Status Low Average High Total M 4.83* M 6.36* M 6.30* M 5.83 High SD 4.91 SD 4.63 SD 8.03 SD 6.10 M 4.25* M 4.38* M 3.91* M 4.18 Low SD 4.65 SD 6.05 SD 6.23 SD 5.69 M 4.54 M 5.37 M 5.11 M 5.00** Combined SD 4.79 SD 5.48 SD 7.28 SD 5.95 *N = 36. **N = 216. Analysis of Table l7.--Inspection of Table 17 revealed that the group with the low level of intelligence had the lowest mean points accumulated for speeding but that the group differences between levels of intelligence were not as great as the differences between means for socio- economic level groups. To determine if the differences were significant, analysis of variance, of a 2 x 3 design with equal cell frequencies, was made and a summary of the analysis is recorded in Table 18. 46 Table 18. Analysis of variance of points accumulated for Speeding, from July 1, 1960 to June 30, 1965, for interviewed subjects grouped according to intelli- gence and socio-economic status Source df MS F Socio-economic 1 146.68 4.12* Intelligence 2 13.06 .36 Soc.-econ. x intel. 2 16.08 .45 Within 210 35.53 .... *P < .05. Analysis of Table 18.--The F ratio for socio-economic status was 4.12 and exceeded the 3.84 required for signifi- cance at the .05 level. However, intelligence did not appear as a significant factor in the analysis of points accumulated for speeding. The second breakdown, points accumulated for viola- tions other than speeding, was also independently evaluated and the means and standard deviations are recorded in Table 19. 47 Table 19. Means and standard deviations for points accumu— lated for violations other than Speeding, between July 1, 1960 and June 30, 1965, for interviewed subjects compared on intelligence and socio- economic status Socio- Intelligence Economic Status Low Average High Total M 7.44* M 4.47* M 4.16* M 5.36 High SD 5.58 SD 4.45 SD 5.04 SD 5.25 M 7.38* M 4.50* M 3.77* M 5.22 Low SD 7.46 SD 5.55 SD 4.00 SD 6.05 M 7.41 M 4.48 M 3.97 M 5.29** Combined SD 6.59 SD 5.03 SD 4.55 SD 5.67 *N = 36. **N = 216. Analysis of Table l9.——Inspection of Table 19 revealed that socio-economic status means were nearly the same in each of the intelligence categories and that the low intelligence level group had a higher mean than the average and high intelligence level groups. To determine if the differences were significant, an analysis of variance of a 2 x 3 design with equal cell frequencies was made, of which was recorded in Table 20. a summary 48 Table 20. Analysis of variance for points accumulated for violations other than Speeding, between July 1, 1960 and June 30, 1965, for interviewed subjects compared on intelligence and socio-economic status Source df MS F Socio-economic 1 1.04 .03 Intelligence 2 248.59 8.10* Soc.-econ. x intel. 2 .87 .02 Within 210 30.68 .... *P < .01. Analysis of Table 20.--Only the factor of intelli- gence appeared Significant with an F value equal to 8.10 which exceeded the 4.61 required at the .01 level of signif- icance. Because of this significance the means of the intelligence groups with combined socio-economic levels were arranged in ascending order and compared using the Newman- Keuls method. A summary of the comparison is contained in Table 21. 49 Table 21. Comparison of means of intelligence groups with socio-economic levels combined for points accumu- lated for violations other than speeding between July 1, 1960 and June 30, 1965 Intelligence Level High Average Low Means 3.97 4.48 7.41 High 3.97 .... .51 3.44 Average 4.48 .... 2.93 Low 7.41 .... A schematic summaryiof Table 21 is as follows.-- High Average Low Treatments underlined by a common line (High-Average) do not differ; treatments not underlined by a common line (High-Low, Average-Low) do differ at the .01 level of significance. Generally speaking the data presented in Tables 15 through 21 on points accumulated over a five year period seem to indicate that intelligence and socio-economic status did not influence the total number of points accumulated within the five year period. However, an inSpection and subsequent analysis of the driving records indicated that subjects from the high socio-economic groups had received more points for Speeding violations than the subjects from the low socio-economic groups. Further analysis indicated that subjects with low intelligence had more points for 50 violations other than speeding than the average and above average intelligence groups. Driving Exposure Data From the subjects interviewed, various estimates of their driving exposure were obtained. was to questions relating to miles driven per year. One set of responses The means and standard deviations for the responses are recorded in Table 2 2. Another aSpect of driving exposure was obtained in responses to questions pertaining to hours a day spent in a motor vehi cle. responses are summarized in Table 23. The means and standard deviations of these Table 22. Means and standard deviations of subjects' ' estimates of miles driven per year, interviewed subjects Socio- Intelligence Economic Status Low Average High Total M 11,555* M 13,944* M 11,305* M 12,260 High SD 9,510 SD 10,020 SD 9,010 SD 9,600 M 12,500* M 11,250* M 11,361* M 11,700 Low SD 9,920 SD 9,380 SD 11,440 SD 10,300 M 12,027 M 12,597 M 11,332 (M 11,980** Combined SD 9,730 SD 9,800 SD 10,290 SD 9,960 *N = 36. **N = 216. 51 Analysis of Table 22.--Inspection of Table 22 did not reveal any trends and an analysis of variance did not indicate any significant differences between groups in the -- miles driven per year. Table 23. Means and standard deviations of subjects' estimates of hours a day in a motor vehicle, interviewed subjects Socio- Intelligence Economic Status Low Average High Total M 2.69* M 1.91* M 2.38* M 2.33 High SD 1.68 SD 1.03 SD 1.75 SD 1.55 M 3.38* M 1.83* M 2.00* M 2.40 Low SD 2.22 SD 1.23 SD 1.97 SD 1.98 M 3.04 M 1.87 M 2.19 M 2.37** Combined SD 2.00 SD 1.14 SD 1.87 SD 1.78 *N = 36. **N = 216. Analysis of Table 23.--Inspection of Table 23 revealed little variation in hours for socio-economic status, however, the low intelligence level group reported Spending a higher number of hours in the car than the average and high intelligence levels. and a summary is recorded in Table 24. An analysis of variance was made 52 Table 24. Analysis of variance of subjects' estimates of hours a day in a motor vehicle, interviewed subjects Source df MS F Socio-economic 1 .29 .09 Intelligence 2 26.17 8.80* Soc.-econ. x intel. 2 5.61 1.88 Within 210 2.97 .... *P < .01. Analysis of Table 24.--The F value for the factor of intelligence was 8.80 which exceeded the 4.61 required for significance at the .01 level. Because of this significance the means of the intelligence groups with combined socio- economic levels were arranged in ascending order and com- pared using the Newman-Keuls method. A summary of the com- parison is contained in Table 25. 53 Table 25. Comparison of means of intelligence groups with socio-economic levels combined for subjects' estimate of hours a day in a motor vehicle Intelligence Level Average .High Low Means 1.87 2.19 3.04 Average 1.87 .... .32 1.17 High 2.19 .... .85 Low 3.04 .... A schematic summary of Table 25 is as follows.—- Average ngh Low Treatments underlined by a common line (Average-High) do not differ; treatments not underlined by a common line (Average— Low, High-Low) do differ at the .01 level of significance. Generally speaking data presented in Tables 22 through 25 on driving eXposure seem to indicate that intel- ligence and socio—economic factors did not influence the number of miles the subjects drove their vehicles. However, further analysis of the data on driving exposure indicated that the subjects within the low intelligence group had spent more hours per day in an automobile than those sub- jects assigned to average and above average intelligence groups. 54 The 216 added subjects were randomly selected from driver education records. There was a difference in the percentage of interviewed subjects who reported enrollment in a driver education course. Table 26 shows the different percentages reported by the various groups. Table 26. Percentage of subjects reporting enrollment in a driver education course Average (Not Low Average High Interviewed) High SES 78%* 97%* 100%* 10094-1: ** Low SES 89%* 92%* 97%fi 100%*** Average of Group 84%** 95%** 99%** 100%**** *N = 36. **N = 72. ***N = 108. ****N = 216. The low intelligence group reported less enrollment in driver education classes. The differences that exist may have been due to two factors. One, is that they do have a lower incidence of enrollment in driver education classes. The second reason may have been caused by the subjects desire to suppress a failure which they have experienced. 55 Evidence to support this view was that 25%.of the low intel- 1igence, high socio-economic status group did not wish to reply to a question relating to enrollment in a driver educa- tion course. Summary of Findings At the onset, a .10 level of significance was set for accepting or rejecting differences. Those comparisons made according to intelligence levels and socio-economic status which indicated no significant differences are as follows: 1. Sum of violations and accidents during a three year period for one—half the subjects (those interviewed) was not significantly different between the groups (Table 5) . 2. Number of violations only, during a three year period for combined subjects indicated no signif- icant differences between the groups compared (Table 11). 3. Number of accidents only, during a three year period, for combined subjects were not found significantly different between the groups compared (Table 13). 4. Total points accumulated for all violations during a five year period for interviewed subjects were not significantly different between the groups (Table 15). 56 Responses to questions concerning the miles driven per year by subjects resulted in no significant dif- ferences between the groups compared (Table 22). Points accumulated for violations other than speed- ing during a five year period for interviewed sub- jects indicated no significant differences between socio-economic status groups (Table 19). Other comparisons made according to intelligence levels and socio-economic status which did indicate signife icant differences are as follows: 7. Sum of violations and accidents (comparisons two and three) during a three year period for combined sub- jects, indicated significantly more violations and accidents for the low intelligence levels than for the average (not interviewed) intelligence level (Table 9). Points accumulated for Speeding during a five year period, comparing groups of interviewed subjects, indicated significantly more Speeding points for the high than the low socio—economic status classifica- tions (Table 17). There were significantly more points for violations other than speeding for the low intelligence group than for the average or the high intelligence levels (Table 19). 10. 57 Responses to questions about the number of hours per day spent in a motor vehicle resulted in significant- ly more hours being reported by the low intelligence level than both the average and high intelligence levels (Table 23). CHAPTER V SUMMARY, DISCUSSION AND RECOMMENDATIONS FOR FUTURE RESEARCH may. The purpose of this study was to investigate inter- relationships among driving ability, intelligence, socio- economic status and driving eXposure of males with low, average and above average IQ'S. The subjects for this study were selected from form— er high school students who had attended school between 1960 and 1964, had been issued a Michigan driver's license, and were, at the time of the study, residing within the city limits of Lansing, Michigan. Subjects were assigned to groups on the basis of intelligence scores recorded in their school records. All subjects who were enrolled in the high school special education program for the educable mentally retarded and otherwise qualified for this study on the basis of the criteria listed above, were assigned to the low intelligence group. The socio-economic status of these low intelligence subjects was then determined using demographic census data. 58 59 A median socio—economic index was obtained and assignment to the high or low socio-economic group accomplished. The total number of low intelligence subjects was 72, which meant that 36 were assigned to each socio-economic group. Subjects for the average and above average intelli- gence groups were selected at random from the list of pro— spective subjects who satisfied the criteria for selection listed above, including the added dimension of socio-economic status. The total number of subjects in the average and above average groups was 144. Initial attempts to analyze data on the 216 subjects indicated constriction of the data. In an attempt to alleviate this constriction two groups of 108 subjects each were added to the average intelligence groups. All subjects except these added 216 were inter- viewed. Official State of Michigan driving records of the male educable mentally retarded subjects were compared with the driving records of subjects assigned to the average and above average intelligence groups. The interrelationships between intelligence levels, socio-economic status levels, accidents, violations and driving exposure were compared. The original 216 subjects were interviewed to obtain estimates of number of miles driven per year as well as the number of hours spent in a motor vehicle each day. In addi- tion, information on participation in driver education courses while in high school was obtained by the interviewer. 60 Analysis of variance was used to determine if signif- icant differences existed between group means. When signif- icance appeared an individual comparison of means using the Newman-Keuls procedure was used. A .10 level of signifi- cance was established as the critical value of accepting or rejecting differences. The following is a summary of the results of the comparisons made in this investigation. 1. Sum of violations and accidents during a three year period for one-half the subjects (those interviewed) was not significantly different between the groups (Table 5). 2. Number of violations only, during a three year period for combined subjects, indicated no significant dif- ferences between the groups compared (Table 11). 3. Number of accidents only during a three year period, for combined subjects were not found significantly different between the groups compared (Table 13). 4. Total points accumulated for all violations during a five year period for interviewed subjects were not significantly different between the groups (Table 15). 5. ReSponses to questions concerning estimates of the miles driven per year by subjects resulted in no significant differences between the groups compared (Table 22). 61 Points accumulated for violations other than speed- ing during a five year period for interviewed sub- jects indicated no Significant differences between socio-economic status groups (Table 19). Other comparisons made according to intelligence levels and socio-economic status which did indicate signif- icant differences are as follows: 7. 10. ,Sum of violations and accidents (comparison two and three above) during a three year period for combined subjects, indicated significantly more violations and accidents for low intelligence level subjects than for the average (not interviewed) intelligence level (Table 9). Points accumulated for speeding during a five year period, comparing groups of interviewed subjects, indicated significantly more Speeding points for the high than the low socio—economic status classifica- tions (Table 17). There were significantly more points for violations other than Speeding for the low intelligence group than for the average intelligence level (Table 19). Responses to questions about the number of hours a day Spent in a motor vehicle resulted in significant- ly more hours being reported by the low intelligence level than both the average and high intelligence levels (Table 23). 62 Discussion The review of related research pointed out the diffi- culty researchers have had in identifying factors which would be useful in predicting driving behavior of the potential driver. In fact, the literature seems to indicate that it is unrealistic to eXpect that any one behavioral or environmental factor could be completely reliable in predict- ing driving behavior. Generally, the procedures employed by previous investigators were confined to looking at one fac- tor, such as intelligence, and its relationship to driving behavior. The present study was designed to look at driving behavior and its relationship to the intelligence and socio- economic status of the individual. This design in driver behavior research produced some interesting findings, some of which are worthy of additional discussion. 1. The results indicate that drivers of low intelli- gence tend to receive more citations for moving violations, other than speeding, than drivers of average or above average intelligence. Perhaps lower intellectual ability becomes a vital factor in complex traffic situations and the lack of ability to handle the myriad number of driv- ing problems which arise in the course of driving results in a greater amount of citations for indi- viduals in this group. Another eXplanation is that 63 persons in the low intelligence group tend to do more driving in the area of their residence. In a city such as Lansing, where there is a high viola- tion enforcement index reported by the police depart- ment, this could result in more citations for viola- tions other than Speeding. However, the investigator is inclined to believe both factors, poorer driving ability and more driving in a high traffic enforce- ment area, are together a plausible eXplanation for this significant finding. An implication of this finding for the driver education program is that the student might find it more profitable, in terms of developing acceptable driving habits, to spend more time in complex, actual driving eXperienceS, rather than theoretical classroom situations. For example the driver educa- tion student who is certified as educable mentally retarded may profitably Spend a greater amount of his training time behind the wheel of an automobile practicing driving in an urban rather than rural or suburban area. This would not only minimize the student's potential driving weakness but would also utilize a recommended method in teaching the low intelligence person, i.e., learning by doing. 64 The findings indicate that low intelligence drivers tend to be involved in more accidents and violations than drivers of average or above average intelli- gence. Accidents and violations are factors which may contribute to the total number of points on a driver's record. However, an interesting point is that the percentage of drivers involved in accidents and violations is approximately the same for all groups regardless of level of intelligence. This means that the overall poorer driving record of the low intelligence group can be attributed to a higher incidence of accidents and violations for certain individuals within the group. In one way it may be said that when a person of low intelligence is a bad driver (a number of citations for accidents and vio- lations) they are in fact a poorer driver than a bad driver of average or above average intelligence. The above statement has implications for driver re-examining agencies. The usual driver re-exam consists of an interview with the traffic violator and then the interviewer making an evaluation of the subject's capacity to change his driving pattern of committing traffic violations. The low intelligence traffic violator should not only be required to sub- mit to a personal interview but should also be required to perform actual driving maneuvers in 65 normal traffic conditions. It may be possible that the low intelligence violator cannot drive in a manner differing from his established pattern. This difficulty may not be apparent in an interview but might be discernible to an examiner observing the subject drive. Interview data indicate that the subject estimates of the number of miles driven per year do not appear to be different among the groups. Number of hours spent in a motor vehicle reported by the low intelli- gence group was significantly more than reported by the average and above average intelligence groups. It is possible that this can be attributed to poor judgment of time by the low intelligence group. A more likely answer is that the use of a car reflects a cultural pattern for these young low IQ adult males. This may be their way of eXpressing emancipa- tion from the home and/or it may be compensation for ”an inadequate self-concept. Automobiles in our cul- ture may be used by many young people to express their independence from parental influence and the low IQ person may use this device to escape from parental ties much more than the other groups studied. Automobile manufacturers have spent huge sums of money to create a public image of their product that includes such factors as power, Speed, 66 status, youth or manliness. Operation of an auto- mobile symbolizes a personal acquisition of one or more of these factors. Therefore, the low IQ group may have found that the use of an automobile is the most convenient way to Show they are as good as any- one else--by borrowing the status or public image of the car as their own. The implication for the Special education and driver education teacher is that they should help provide the student with some other means by which low intelligence subjects can further enhance their self-concept without the dangers inherent in traffic. Parents too, should be helped to understand the pro- cedures a youth utilizes in becoming independent from his parents. They then could more adequately help their young adults assume the role of indepen— dence from the parents. The results of this study suggest that drivers from the high socio-economic groups tend to have more citations for Speeding than drivers from the low socio-economic groups. The higher the incidence of citations for Speeding by the high socio-economic group may be a manifestation of antisocial reactions for violators within this group. Hollingshead (1958, p. 231) reported a greater tendency of neu- rotic antisocial behavior among persons having a 67 high socio—economic status than for persons having a low socio-economic status. However, there is the possibility that subjects in the high socio—economic group drove a more expensive and powerful automobile and exceeded the speed limit in an unintentional manner. But if Speeding is a manifestation of anti- social behavior for the high socio-economic offenders, then the concept of traffic law violations as a sub- species of folk crime as suggested by Erwin O. Smigel and develOped by H. Laurence Ross (1961) has addi- tional support. The finding that people in the high socio- economic group receive more citations for speeding has the same implication for the driver education teacher, the law enforcement officer and the reli- gious counsellor. The author believes that Speeding is generally a willful act. The findings indicate that drivers in the high socio-economic groups may not view this behavior as improper. The author also feels that economic sanctions, which are usually employed by traffic courts, while a detriment to speeding, are not as effective as instilling in the driver a sense of responsibility to his fellow driver. The driver education teacher, the enforce- ment officer, and the institutions they represent should promote a morality of driving in their [I '1 III II III!" I ‘ l 68 contacts with students, the public, church congrega- tions 23 El. For example, the driver education teacher should stress not only the mechanical and physical aspects of driving but also the social and moral implications of imprOper driving. The enforce- ment officer and judge might incorporate in their treatment of traffic offenders a moralistic implica- tion for traffic violators antisocial acts. On the basis of the findings reported in this inves- tigation the following conclusions, concerning the population under study, are made:; 1. Intelligence and socio-economic status do not appear to be predictive of number of violations a driver will commit. Intelligence and socio-economic status do not appear to be predictive of number of accidents in which a driver will become involved. Intelligence and socio-economic status do not appear to be predictive of the total number of "points" which a driver will receive for having committed traffic violations. Intelligence and socio-economic status do not appear to be predictive of the number of miles a person will drive his automobile per year. 69 AS a group of drivers educable mentally retarded males have a larger total of combined convictions for traffic violations and involvement in accidents than groups of male motorists with average intelli- gence scores. It should be noted that an individ— ual's IQ score in and of itself is not necessarily predictive of driving performance. Socio—economic status tends to predict the propor— tion of points a driver will receive for speeding violations. Intelligence tends to predict the proportion of points a driver will receive for moving violations, other than speeding. Intelligence tends to predict the number of hours a driver will spend per day in an automobile. Recommendations for Future Research The results of this investigation seem to warrant additional research. Specifically, 1. What factor(s) in the high socio-economic group resulted in their accumulation of "points? for Speeding violations? What specific factor(s) resulted in the low intelli- gence group receiving more "points" for moving violations, other than Speeding? 70 The significance discovered by comparing parti- tioned types of violations may further understanding of factors contributing to accidents and violations. Answering the two aforementioned questions would analyze violation and accident data according to some constituents. Serviceable research groupings for use in the above questions might be according to conditions existing during an event such as: (1) type of injuries, (2) number of fatalities, (3) extent and type of property damage, (4) driving rule violated, and (5) relationship to other vehicles or people. Such categories could define driving weak- nesses in a manner which would permit development of accident avoidance techniques for use in driver education classes and more judicious law enforcement by traffic enforcement agencies. It would appear to be of considerable value to duplicate the procedures used in this investigation utilizing a larger number of subjects to enable a more thorough analysis of the constituent factors uncovered in this investigation. With a more accu- rate defining of the population through larger num— bers significant findings might result between more intelligence groups. 71 The correlation between personality factors and intelligence was not examined by the researcher. If there is a correlation of these factors a new insight into driving behavior may be possible. The possibility exists that the factors investigated could be analyzed using multiple correlation analy- sis and produce significant indicators of driving ability. Finally, this research was confined to males only. Further research to determine if the same results would occur for female subjects should be undertaken since females are becoming involved in more business and social activities that require that they drive an automobile. Research designed to clarify issues identified by this investigation should strive to eliminate the inherent limitations of the present study. Specifically, 1. The fact that two types of intelligence tests were used in determining the subjects utilized in this research remains a procedureal limitation. However, the specific tests used in the Lansing Public Schools minimized this factor. .The California Test of Mental Maturity was employed for the group test, while the Revised Stanford-Binet Scale and Wechsler Intelli- gence Scale for Children were used as individual 72 tests. In regard to the California Test of Mental Maturity, Freeman (1959, p. 437) states in Buros Fifth Mental Measurements Yearbook: On the whole, the coefficients result- ing from these validating studies, which were carried out by investigators other than the authors of the scales, are satis- factory or even high, especially in the case of the Stanford-Binet and Wechsler Scales. Further, Haworth states in Buros (1959, p. 547): "Correlations between the WISC and Stanford-Binet range from the .60's to .90's." The mean intelli- gence quotient for all three tests was 100 and the standard deviation reported for the WISC (Buros, 1959, p. 558) is 15, for the Stanford-Binet the standard deviation is, according to Buros (1959, p. 547), 16.4. The Same source (Buros, 1959, p. 436) states that the California Test of Mental Maturity has a standard deviation of 16. This evidence tends to reduce the limitation of using different types of tests. Using a demographic basis for determining socio- economic status may have resulted in a subject being placed in an imprOper socio-economic classifi- cation due to intra-block differences. The census data is based on a block average and any particular subject may have deviated to the extent of actually 73 being in a classification other than that of the block norm. Not all driving violations are registered by police officers, therefore the Secretary of State's record undoubtedly represents less than actual driving infractions of the subjects. Violations which result in accidents are also more strictly noted on the driver's record than those which are not asso- ciated with accidents. Therefore those violations which do not cause accidents may not be truly represented in the driving record of a traffic violator. Since interviews are subjective the data obtained by this method is probably not as uniform as might be obtained through an objective technique. The interviews, although conducted by professional per— sonnel who were instructed in a uniform approach to the subjects, undoubtedly varied the interview pro- cedure when interpersonal reaction demanded varia- tion. This variance of interview techniques may have resulted in a variance of interpreting and recording the data concerning hours spent in a car per day or miles driven per year. Also, validation of these findings on driving exposure is not pos- sible through any practical means now available to the researcher. {lull "Il‘i‘ l I ‘f‘ I. ll. 74 Several important factors must be considered in evaluating the results of this research. These include the subjects, all of whom were residents of Lansing, Michigan, where public transportation and its use are on the decline while the population and area of the city are on the increase. The result is a need and a custom or habit for these subjects to drive more miles than would be eXpected in a loca- tion where public transportation is more readily available. Also, an inestimable influence on the research is the favorable economic condition in Lansing, Michigan which provides for reduced finan— cial restrictions on driving vehicles not only for the subjects but for other drivers in the area. It is conjectured that there is greater driving expo- sure for the subjects under more congested driving conditions than during unfavorable economic periods thus producing more vehicular interaction. An observer might validly question whether the results obtained in this research are equally valid in areas where there is not as much traffic. REQUEST FOR MICHIGAN DRIVER RECORD INFORMATION, APPENDIX A Lansing Public Schools c/o Robert W. Gutshall Lincoln School Lansing, Michigan OC-70 (State Dept. Account No. License No. (Impertant) Name First Middle Last Address Oper. lic. chauf. lic. Birth expires on l9__ eXpiration This s ace for use of com- Date birthday, date any submitting request FINANCIAL RESPONSIBILITY RECORD 7 Conviction Date CASE or ' Action NO. Accident Date Reason for F.R. Action Location Lifted Probate Court Finding or Offense, Accident, Conviction Arrest Accident Location or Dept. Action Date Date Date LOCATIONS .1. Detroit 6. Grand Rapids A. Speeding G. Reckless 2- Highland Park 7. Kalamazoo B. Ran red light driving 3- Lincoln Park 8. Lansing C. Ran Stop sign H. Interfering 4° Idfilonia 9. Flint D. ImprOper left with traffic 5- Dearborn 10. Saginaw turn I. Failure to (All others written) E. Improper yield right right turn J. Basic speed F. Improper passing (All others written) 75 . :11" (I. l 76 o m o H 4 OH H mm HN ON 4 m o m 4 Nm m Hm NN NH 4 o N N 4 o 4 HS ON mH N m o H 4 N 4 we NN SH MH SH 0 n 4 mH m HS NN 0H N o o H U h H no 4N mH- m o o o 4 H H 4o MN 4H m «N H m 4 0H N eh mN MH m o H m 4 H N H@ MN NH 0H 0 H m m m 4 mo 0N HH OH h N m 4 mH H mm HN OH > m o m 4 H N mm 0N m mN h m 4H 4 mm m om HN m HN m N n m H H mm 4N w NH NH H o 4 mm m om 0N w m 0H 0 N 4 0H N Sh «N m m w m m 4 v N Nm HN w m o o H 4 H m mo HN m m m o o 4 m H no HN N m o H N 4 m H mm NN H cOHuom COHHom onuom coHHom Ho3mc4 Aooo.H mom mom OH omIHIH @MIH Hmow m Amok m Meow m “mow m ozuo Homv HMO mo .02 4 Ho>o 4 uo>o 4 Hm>o 4 Ho>o oznm cm>HHQ cH .mHm m4 mm4 msuoon .DMH0H> .omomm .UHUU4 .DMH0H> mmwu4 .HM Hmm Innm Honuo Mom Hom .osom mmHHS mucHom mucHom .>HHQ coon>HoucH .mspmum UHEocoomIOHUOm cmHs nqu om BoHon OH on on: umnu muoonQSm om .mocmmHHHoucH 30H mm GOHMHmmMHU ”H msouo BUMbOMQ HEB ZH DmmD 4949 UHmfim BZmZHBmmm m NHQZQQQfi 77 h m H N m mH m Hm NN Om O O H H 4 OH N on ON mm OH b H m 4 OH 4 Sb mN cm HH 5 H O 4 O H on HN mm m h s h 4 OH O OO HN Nm m s O m 4 ON m hm HN Hm OH O O O 4 HN N «h mN Om OH O H m m ON m Nb HN ON O N H n O NH m Sh OH ON h w m w 4 m N Nb OH SN O O O O m m N Ow OH ON O N H H 4 O m cm OH mN NH m O m 4 ON 0 NO ON ON N O O O m m H Oh mN MN O O O O 4 m m Oh NN NN h m w m 4 SH H eh 4N HN cossmm cosmos uossms sosumm segmse Aooo.H Nan sms 0H OOIHIH smuH Hmow m Hmmw m Moo» m Hmow m ozno Homv HMO mo .02 4 Ho>o 4 Hm>o 4 Hm>o 4 Ho>o oznm co>HuQ CH .mnm m4 om4 m.uoon .DMHOH> .Oommm .OHUU4 .DMH0H> wmwu4 .HM Mom InSm Hocuo Mom Mom .osOm moHHz mucHom mucHom .>HHO UOSGHDGOUIIH msouw illlallllllcl'l'l'llll“ 78 OHH N M O N 4 O H OHH HN O OH H w 4 OO N OO MN NHH M HH O M 4 NH N OO MN OHH MH O O O 4 ON N OO MN OHH O O H O 4 M N HO ON OHH O OH O M 4 OH H OO 4N MHH m m N w 4 MH N OO ON NHH OH M H n 4 OH H OHH ON HHH S O o m 4 ,OH M OO MN OHH N O O M 4 OH N MOH OH OOH S OH N n 4 O N HOH HN OOH N M H N 4 MH N OOH ON MOH O O M h 4 ON M OOH OH OOH O O H O 4 ON M mOH OH mOH O O O N 4 MH H OHH OH OOH O M O H 4 O N OHH HN MOH O O O H 4 M H OOH OH NOH N OH H m 4 ON N OO ON HOH GOHHOnH OOHHOQ UOHHOA UOHHOQ Hw3mc4 A000 .H \HMQ HO& OH OOIHIH OMHIHOH Hmmw m Ham» m Hmmw M Ham? M ozuo mev HMO mo .02 4 nm>o 4 Hm>o 4 Hm>o 4 Hm>o ozum cm>HHQ cH .mum m4 mO4 m.uomn .DMH0H> .Ommmm .OHoo4 .OMHoH> mmwu4 .HM Hmm IQSO Hmnuo uom Mom .USOO mmHHz mucHom mucHom .>HHQ Om30H>HmucH .msumum UHEocoomIOHUOm £OH£ £DH3 OHH ou OO Eoum OH cm Om: umnu muomnndm OM .mocmOHHHmucH mmmnm>m mm OmHmHmmMHO «N msouw 79 O O H m 4 OH O NOH NN OMH O O O O 4 NH M OOH HN MMH O O O H 4 OM H OO HN OMH M M O H 4 m N OHH HN MMH N N H N 4 OH H SO HN NMH OH OH H O 4 OH H NOH ON HMH O HH H O 4 m N MOH ON OMH m O O M 4 ON O OOH HN ONH O O N N 4 H H OOH HN ONH M O H M 4 OH H OO OH SNH OH MH N m 4 MM M SOH MN ONH O O O N 4 OH N OOH HN MNH M m O H 4 ON H OOH NN ONH N O H H O H N NOH OH MNH O O O O 4 S H OO MN NNH S NH H O 4 O N mOH OH HNH M S M H 4 O H OOH NN ONH O O H N 4 OH H OO HN OHH OOHHom OOHHmm OoHHmm OOHHmm Hm3mc4 AOOO.H HMO Hmm OH OOIHIH OMHIHOH HMO» m HMO» m HMmN M Hme M ozuO Hmmv HMO mo .02 4 Hm>o 4 Hm>o 4 Hm>o 4 Hm>o oznm cm>HHO cH .MHm m4 mO4 m.uowfl .HMH0H> .Ommmm .OHoo4 .uMH0H> mm>u4 .HM Hmm Insm Hmnuo Hom Hom .osum mmHHz mucHom mucHom .>HHQ OODGHHGOOIIN OSOHO 80 M O O H 4 H N MHH OH OOH N M O H 4 OH N OHH NN SOH N O H M 4 H H OHH MN OOH N O O O 4 O H OHH OH OOH O O O N 4 HH H ONH ON OOH N N H H 4 O N OHH ON MOH O O O O 4 O H OMH HN NOH OH O O S 4 O N MNH OH HOH O O O O 4 ON M OHH HN OOH O OH O H 4 SN O OHH MN OOH N O N M 4 MH O NNH ON OOH O S N O 4 O N MHH ON SOH O O H N 4 H H MNH OH OOH N M N N 4 OM O OHH NN OOH O O O O 4 NH N SHH HN OOH NH NN H MH 4 SH M OHH OH MOH O OH O M 4 H H OHH OH NOH O O O O 4 O N HHH ON HOH OOHHmO OoHHmm OOHHOO OoHHmm Hm3mc4 AOOO.H SMQ Hmm OH OOIHIH OOHIHOH HMmN O HMmM O HMmN M HMmM M ozuO Hmmv HMO mo .02 4 Hm>o 4 Hm>o 4 Hm>o 4 Hm>o ozum cm>HHQ CH .MHO m4 mO4 m.uomfl .uMHoH> .Ommmm .OHoo4 .HMH0H> mmwu4 .HM Hmm . IQDO Hmnuo Hom Hom .UDOO mmHHz mucHom mucHom .>HHO Ow3mH>HmHGH .mSHMum OHEOGOUOIOHUOM ems: sst OHH m>ons 0H as Ms: sass muomflesm Om .musmmHHHmusH ems: mm MmHMHmmmHo "m msoso 81 O O O O 4 OH H MNH OH OOH O HH O O 4 OH N OMH OH OOH NH NH H O 4 ON S NNH HN OOH O O O O 4 HN N MNH NN mOH O O O O 4 O O MHH HN NOH O M H H 4 O H NOH OH HOH O O O O 4 OH H OMH OH OOH O OH O O 4 ON M NNH NN OSH O O O O 4 O H OHH ON OSH MH O N N 4 O N SHH MN SSH NN OM O OH 4 OH N OHH NN OSH O O H O 4 ON N OHH ON OSH O O H O 4 OH N OHH ON OSH N O H H 4 N N MNH OH MSH O M O O 4 O H ONH NN NSH O O H N 4 O H OHH OH HSH O ON N O 4 OM O NHH NN OSH O O O O 4 O N ONH ON OOH OOHHOO OoHHmm OOHHmm OOHHOO Hmzmc4 AOOO.H OMH Hmm OH OOIHIH OOHIHOH HMO» O Hme O HMmM M Hme M ozuO Hmmv HMO mo .02 4 Hm>o 4 Hm>o 4 Hm>o 4 Hm>o ozum cm>HHQ cH .mHm m4 mO4 m.uomn .HMH0H> .Ommmm .OHUU4 .uMH0H> mmwn4 .HM Hmm IQSO Hmzuo Hom Hom .osvm mmHHz MUCHOO mucHom .>HHQ OOJGHHGOOIIM OSOHO 82 O OH O O 4 HOH NN ONO O NH O O 4 MoH HN ONO O M H M 4 OOH ON SNO OH SH M O 4 SOH NN ONO O O M O 4 OOH HN ONO O M O O 4 OOH HN ONO O NH O O 4 OO HN MNO N O H H 4 OO MN NNO O O O O 4 OOH HN HNO O O O O 4 OOH ON ONO O O O O 4 OOH HN OHO O S O H 4 MO MN OHO O N O H 4 OO HN SHO O O H O 4 HO MN OHO N N H H 4 OOH MN OHO N NH O O 4 OOH HN OHO M O N H 4 HO OH MHO O O H O 4 OOH ON NHO N O H H 4 SOH ON HHO O O H N 4 HOH OH OHO O O O O 4 OO ON OOO O O H O 4 SO OH OOO O O H O 4 OOH OH SOO N O O O 4 NOH MN OOO O MH H O 4 OOH MN OOO O MH N O 4 OO HN OOO O S O O 4 SOH OH MOO O S O N 4 HOH MN NOO N O M M 4 OOH OH HOO OOHHOO OOHHOO OOHHOO OOHHOO Hm3mc4 OZHO OH OOIHIH OOOIHOO .Hw O 4 HO>O .HM O 4 HO>O HMON M HMON M 02 u m mo HOHESZ .HMHOH> Hmnuo OGHOOOOO 4 HO>O 4 HO>O MOM u 4 m4 OO4 m.uommnfim Hos mucHom Hos mueHom .MH004 .OMHOHS .ost .>HHO msuMum UHEOOOOOIOHOOM SOH: ODH3 OHH OH OO SOHO OH OM OMO HMEH muomnnsm OOH .AOOBOH>HOHOH Hocv OOGOOHHHOHGH OOMHO>M MM OOHmHmmMHO "O OOOHO 83 O NH N S 4 SO HN OOO O N H H 4 OHH ON SOO O O O O 4 NO ON OOO OH OM N NH 4 OO- ON OOO O O O O 4 OOH OH OOO OH M H O 4 OO HN MOO O O O N 4 NOH ON NOO O O O O 4 OHH HN HOO M O O H 4 MOH ON OOO O O O O 4 SO ON OOO O O O O 4 NOH OH OOO O O N O 4 OOH ON SOO O N O H 4 OOH ON OOO O O O O 4 OO HN OOO O O O O 4 OOH ON OOO O O H O 4 SO ON MOO N O O H 4 SOH OH NOO O OH N S 4 OOH OH HOO HO ON M SH 4 OOH HN OOO N O H H 4 SO MN OMO O O N O 4 OO OH OMO O O H O 4 MOH OH SMO S HH M O 4 OOH NN OMO N HH H N 4 OOH MN OMO N O O N 4 SO MN .OMO O O O H 4 OOH MN MMO S O H H 4 OO HN NMO O O H N 4 OOH MN HMO O OH O N 4 OOH NN OMO OOHHOO OOHHOO OOHHOO OOHHOO Hm3mc4 OzuO OH OOIHIH OOOIHOO .H% O 4 Hm>o .Hw O 4 Hm>o HMON M HMOM M oz H O HO HOHEDZ .HMHOH> Hmnuo OOHOOOOO 4 Hm>o 4 HO>O MOM n 4 m4 OO4 m.uomnnsm Hom mucHom Hom MHGHOO .OHoo4 .HMHOH> .osvm .>HHO OOSCHHCOOIIO OSOHO 84 O O O O 4 NOH ON MOO O OH O M 4 OO NN NOO O O H O 4 OOH NN HOO O O O H 4 OHH NN OOO O OH N N 4 SO NN OSO O S O O 4 SOH MN OSO O N H H 4 OOH ON SSO O M O H 4 OO ON OSO O O N o 4 OOH OH OSO S O N O 4 OO HN OSO N OH N O 4 OHH ON MSO O O O H 4 OOH ON NSO O O O M 4 SOH NN HSO N O H N 4 OOH NN OSO N. O O O 4 OO HN OOO O ON H .O 4 OO HN OOO N S N O 4 SO HN, SOO S M N O 4 OOH HN OOO O O O O 4 OOH OH OOO N O H O 4 OOH MN OOO O O H O 4 HOH HN MOO O O O N 4 OO HN NOO M O O H 4 SO OH HOO O N O H 4 OOH ON OOO HH M H O 4 SOH HN OOO OOHHOO OOHHOO OOHHOO OOHHOO HO3mc4 ozuO OH OOIHIH OOOIHOO .Hw O M HO>O .HM O 4 HO>o HMOM M HMON M 02 n O HO HOQESZ .HMHOH> Hmsuo OOHOOOQO 4 HO>o 4 HO>o mm% H 4, m4,OO4 m.uomnnsm Hom chHom Hom mucHom .OH004 .HMHOH> .ODOO .>HHO OOSGHHOOOIIO OSOHO 85 M OH O H 4 OOH MN OOO N O O H 4 OOH ON SOO M O O M 4 OO ON OOO O O H N 4 MO OH OOO O O H O 4 MOH MN OOO MH O N O 4 OHH NN MOO O NH O H 4 MOH MN NOO N O O O 4 OO HN HOO N N M N 4 MOH ON OOO N O O O 4 HOH NN OOO M O O H 4 OO MN OOO O O N H 4 OOH HN SOO N O O M 4 OOH NN OOO OH O H O 4 OO OH OOO O O N N 4 OOH HN OOO N N N N 4 OO ON MOO O O H M 4 OOH MN NOO O O H O 4 OOH OH HOO O O O N 4. NO ON OOO O NN N O 4 OOH HN OOO M N H H 4 OO MN OOO O M H H 4 OOH OH SOO O N O H 4 OOH NN OOO N O O M 4 OO HN OOO O O O O 4 SOH HN OOO OOHHOO OOHHOO OOHHOO OOHHOO HO3mc4 Ozuo OH OOIHIH OOOIHOO .HO O 4 HO>o .HM O 4 HO>O HMO? M HMO» M 02 n O Ho HOQESZ, , .DMHOH> Hmsuo OOHOOOOO 4 HO>o. 4 Hm>o mmw u 4 m4 OO4 m.HOOnH5O HOO mucHom HOO mucHom .384 .umHo; .33 .33 OOSOHHOOOIIO ODOHO 86 HH O H M 4 S N MO ON OO O O O O 4 OH N SS OH SO N O O N 4 OH N SS ON OO OH N O N O O N OO NN OO O O O M 4 O N HO HN OO O O O O 4 N O OS ON MO N O H M 4 O O OO HN NO ON NH M OH 4 ON S OS MN HO O O H O 4 OH H OS HN OO O O O O 4 OH O OS ON OO M O H O 4 OH, O OO MN OO O O O O 4 HN N OO ON SO O M H O 4 HN O MO HN OO OH O O H 4 H H OS NN OO OH M O O O H H OS NN OO O O O O O N H OO HN MO O M O M 4 OH M OS OH NO MH S O O 4 O H NS MN HO MoHHmm MoHHmm coHHmm MOHHmm Hm3mc4 Aooo.H HMO Hum OH OOIHIH OOIHO HMOw O HMO? O HMO» M HMO» M oznO HOOV HMO mo .02 4 HO>O 4 HO>O 4 HO>O 4 HO>O, ozuO OO>HHO OH .mHO m4 OO4 m.uomn .uMHOH> .OOOOO .OHoo4 .uMHOH> mmwu4 .HM HOO Indm HOOuo HOO HOO .OOOO MOHHZ mucHom mucHom .>HHQ l IiIIII IIIlII'I III IIIII III I III I! IIII OO3OH>HOHOH .msuMum OHEOOOOOIOHOOO 30H SHHB OO 3OHOQ OH OM OM: HMOH muomnnsm OM .OUOOOHHHOHOH 30H mM OOHOHMMMHO "O OOOHO 87 O O O O 4 OH N OS HN OO S N H H 4 N N NS HN OO HN O M O 4 M H OS NN OO N O O H 4 mO M OO MN MO OH O H N 4. OH O OS MN NO O O O O 4 O O NO HN HO OH O M S 4 O O OO NN OO N N N N 4 NH H OO MN OS OH O N OH 4 OM M NS ON OS S OH O O 4 OH O OS HN SS MH OH M O 4 N H NO HN OS O O O H 4 H O MS HN OS ON O O O O OH M MO MN OS O O O O 4 O N OS OH MS NH SH M HH 4 OM O mO ON NS OH MH O S 4 ON O MO HN HS O O O N 4 ON O OS HN OS O M H N 4 ON N OS NN OO MoHHmm MoHumm coHHmm coflsmm HmSms4 Hooo.H Ham Ham OH OOIHIH OmnHm HMO» O HMON O HMOM M HMO? M OzuO HOOV HMO Ho .02 4 HO>o 4 HO>o 4 HO>O 4 Hm>o OzuO cm>HHO cH .MHO m4 OO4 m.uomfl .uMHoH> .Ommmm .MH004 .OMHoH> mmHu4 .HH Hum unsm Hmnuo HOO HOO .USOO MOHHS mucHom muCHOO .>HHO OOSGHHGOOIIO ODOHO I II. [[1 II .I ll 1' III II II E all... I Ills-I‘ll 88 O N O H 4 O O OOH OH OHN O O O O 4 OH M SO NN SHN O O N S 4 NO H SO OH OHN O O O N 4 O H NO NN OHN O S H O 4 OH M SO ON OHN O O M O 4 S O OHH ON MHN N HM H O 4 ON N OOH NN NHN N O N M 4 ON O OOH NN HHN M O O O 4 H M OO MN OHN N O O O 4 NH H MO NN OON N M N N 4 O H MOH OH OON S M N O 4 ON H SOH HN SON O MH N H 4 OH H MO MN OON O O O O 4 O H OOH ON OON M N H N 4 S O NOH OH OON N N H N 4 O H MOH HN MoN M O O H 4 OH H HO ON NON O o O O 4 NH H OOH ON HON MOHHmm MoHHmm OOHHON MOHHmm swameO Hooo.H HMO Hmm OH OOIHIH OmuuHoN HMO? O HMO? O HMO? M HMO? M ozuO Hmmv HMO mo .02 4 Hm>o 4 HO>o 4 HO>o 4 Hm>o ozuO OO>HHO OH .MHO m4 OO4 m.uomfl .HMHOH> .OOOOO .OHoo4 .HMHOH> mm?n4 .H? HOO IQOO Hmzuo HOO HOO .OOOO OOHHZ mucHom OHOHOO .>HHO OOBOH>HOHGH .mSHMHM UHEOGOUOIOHUOM 30H £HH3 OHH O» OO EOHH OH OM OM: HMOH muommnsm OM .OocOOHHHOHsH OOMHO>M mM OOHHHMMMHO "O ODOHO 89 ON OH O M 4 OH N OOH NN OMN NN O M O 4 OH N OOH NN OMN O O O O O OH H OOH ON OMN O N O O 4 OH O OO OH MMN O O N O 4 M H OOH ON NMN OH MH H S 4. H H OOH NN HMN O O H M 4, H H NOH ON OMN M O O M 4 M N OO OH ONN O N H O 4 HH H OO HN ONN O O O O 4 OH H SO ON SNN N M O N 4 OH H OO NN ONN O O H O O OH H MO ON ONN HH O H M 4 OH H OOH MN ONN O O O H 4 HN N OOH ON MNN O M H H 4 O H SO NN NNNg N HH O N O ON H OOH NN HNN S O N M 4 O H NOH HN ONN O O O H 4 M M NOH ON OHN OOHHON MOHHmm OOHHME OOHHmm Hmsmc4 Hooo.H SMO HOO OH OOIHIH OMNIHON HMO? O HMO? O HMO? M HMO? M oznO HOOV HMO mo .02 4 HO>O 4 HO>O 4 HO>O 4 HO>O OZHO GO>HHQ CH .MHO m4.OO4 m.uoOh .HMHOH> .OOOOO .OHoo4 .HMHOH> mO?u4 .H? HOO IQSO Hmnuo HOO HOO .OOOO MOHHZ mucHom MHOHOO .>HHO OOOOHHGOOIIO OOOHO 90 HH O M O 4 ON N ONH HN OON O M N O 4 O N OHH NN SON M O O N 4 OM O HHH ON OON M M O N 4 NH H HHH MN OON N O O H 4 O H ONH ON OON HH M H O 4 O H OHH OH MON O O O O 4 OH O ONH ON NON O O H H 4 OH N ONH MN HON O O O O 4 O H OHH OH OON O O H O 4 H H OHH HN OON OH O H M 4 M H OHH OH OON S O O O 4 OH H OHH ON SON M OH H O 4 O H NNH OH OON O O H O 4 H O OHH ON OON O ON O O 4 OH N OHH MN OON O O N N 4 OH O OHH OH MON N O O H 4 ON H MHH NN NON SH ON M OH 4 OO M -OHH OH HON OOHHOO OOHHOO OOHHOO OOHHOO HO3mc4 HOOO.H ?MO HOO OH OOIHIH OONIHON HMO? O HMO? O HMO? M HMO? M ozuO HOOV HMO Ho .02 4 HO>o 4 HO>o 4 HO>O 4 HO>o ozuO OO>HHO cH .mHO m4 OO4 m.HOOfl .HMHOH> .OOOOO .OHOO4 .uMHoH> mO?u4 .H? HOO IQSO HOOHO HOO HOO .ODOO MOHHZ chHom mucHom .>HHO OO3OH>HOHGH .mduMum OHEOGOOIOHUOM 30H OHHB OHH O>OQM OH OM OM: uMnu muomflnsm OM .OOCOOHHHOHGH OOH: MM OOHHHmmMHO "S OSOHO 91 O MH M M 4 ON M ONH MN OON O O O O 4 O H MHH NN OON N O O O 4 OH H MHH HN OON M M O N 4 OH H SHH ON MON O N H O 4 O N ONH NN NON N S H O 4 H H HHH ON HON N O N H 4 O H OMH ON OON O N O M 4 OH H OHH HN OSN O O O O 4 MH H ONH NN OSN O O O O 4 O H OHH MN SSN O O O O 4 O H ONH OH OSN O O .O O 4 N O ONH OH OSN N N H N 4 O H HHH ON OSN O O to O 4 OH H ONH HN MSN N O H H 4 OH H SHH HN NSN O O O M 4 OH H ONH HN HSN O O O H 4 O H SHH MN OSN O O O O O OH H OHH ON OON OOHHmm MOHHOO MOHHOO OOHHOO HOBmSM Hooo.H SMO HOO OH OOIHIH OONIHON HMO? O HMO? O HMO? M HMO? M ozuO HOOV HMO H0 .02 4 HO>O 4 HO>o 4 HO>O 4 HO>O OZHO OO>HHO cH .MHO m4 OO4 m.HOOm .HMHOH> .OOOQO .OHUU4 .HMHOH> MO?H4 .H? HOO IHSO Hmnuo HOO HOO .ODOO mOHHz mucHom mucHom .>HHO OOOOHHOOOIIS OSOHO 92 M O H H 4 OO ON SNM O O H O 4 OOH OH ONM O O O M 4 HOH OH ONM O N O H 4 NO ON ONM M M H H 4 OOH ON MNM N O O M 4 SO ON NNM N O O H 4 OO MN HNM M O O H 4 HOH MN ONM O O O O 4 OO ON OHM M O O O 4 OOH MN OHM O HN H O 4 SO MN SHM O O O H 4 MOH HN OHM O O N O 4 OOH OH OHM O N H M .4 NO ON OHM O HH O O 4 OOH ON MHM O O O M 4 MO MN NHM N O H O 4 HOH NN HHM O O O O 4 HO NN OHM O M H H 4 OOH OH OOM NH N O H 4 MOH NN OOM O O O N 4 OOH OH SOM MN M N O 4 OOH HN OOM MH MH O O 4 MOH NN OOM SH M. M O 4 SOH NN OOM O N M H 4 OOH OH MOM O NH N N 4 OOH MN NOM O O O N 4 OO OH HOM OOHHOO OOHHOO OOHHOO OOHHOO HO3mc4 oznO OH OOIHIH OOOIHOM .H? O 4 HO>O .H? O 4 HO>o HMO? M HMO? M 02 n O Ho HOHEOZ .HMHOH> Hmnuo OOHOOOQO 4 HO>o 4 HO>O mm? H 4 m4 OO4 m.HUOnn5m HOO mucHom HOO mucHom .OHOU4 .HMHOH? .OSOO .>HHO mduMum OHEOGOOOIOHOOM 30H EHHS OHH OH OO EOHH OH OM OMO HMOH mpomflnsm OOH .HOOBOH>HOHCH Hosv OOGOOHHHOHOH OOMHO>M mM OOHHHmmMHO "O ODOHO 93 O O O N 4 OO NN OOM OH NH M HH 4 OOH HN MOM O O O O 4 OOH NN NOM O NH O H 4 NO MN HOM N ON H O 4 OO HN OOM O O N N 4 OHH ON OOM O SH N O 4 SOH HN OOM O O H N 4 SO HN SOM M O N O 4 OOH HN OOM O O O O 4 SOH ON OOM O O H O 4 NOH OH OOM N O N M 4 OOH MN MOM O MH O O 4 SO MN NOM O O H O 4 OO HN HOM N N H N 4 OO HN OOM O O H N 4 OO HN OMM O O H H 4 SO HN OMM N O O M 4 OOH HN SMM N MH H O 4 HO ON OMM O O O O 4 MOH ON OMM O M O N 4 SOH MN OMM O O O H 4 OOH ON MMM N N O N 4 HOH NN NMM N O O H 4 OOH NN HMM O O O O 4 OO HN OMM N O O M 4 MOH ON ONM S O H O 4 OO ON ONM OOHHOO OOHHOO OOHHOO OOHHOO .HO3mc4 OzuO OH OOIHIH OOOIHOM .H? O 4 HO>o .H? O 4 HO>o HMO? M HMO? M 02 n O HO HOQEOZ .uMHOH> Hmnuo OOHOOOOO 4 HO>O 4 HO>o mm? H 4 m4 OO4 m.uomflnsm HOO MOSHOO HOO mucHom .MHUOM .umHoH> .USMM .>HHO OOSCHHOOOIIO OSOHO 94 HMM O O O O 4 SO HN O N O O 4 OHH HN OOM HH O O S 4 OO HN OSM O O O O 4 OO HN OSM O O O O 4 OO OH SSM ,O N O H 4 HOH HN OSM M O O M 4 OOH ON OSM N O H M 4 OOH ON OSM MH OH H O 4 OO HN MSM O M O H 4 OO MN NSM N M H H 4 NOH NN HSM O S H M 4 OOH NN OSM O S O N 4 OO NN OOM O O O O 4 OO ON OOM O O O O 4 MO NN SOM O O H N 4 MO OH OOM O OH H O 4 SOH ON OOM O N O H 4 OOH OH OOM O O H O 4 OOH HN MOM N O H H 4 OO OH NOM O N O H 4 OOH OH HOM O O O O 4 OOH OH OOM O O O O 4 OO ON OOM O O N O 4 OO OH OOM S O H M 4 OO HN SOM O O H O 4 OOH OH OOM N M O N 4 OO HN OOM OOHHOO OOHHOO OOHHOO OOHHOO .HO3mc4 oznO OH OOIHIH OOOIHOM .H? O 4 HO>o .H? O 4 HO>o HMO? M HMO? M oz n O Ho HOAEOZ .HMHOH> Hmnuo OOHOOOOO 4 HO>o 4 HO>O MO? u 4 m4 OO4 m.HOOflQSO HOO mucHom HOO mucHom .cHuoO .umHoH> .osom .>HHO OODOHHOOOIIO ODOHO III‘IIII'I'I'II'II‘II'II‘I‘I El 95 O O N N 4 SO ON OOO O O O O 4 OO OH SOO O O O N 4 OOH NN OOO O N O H 4 OOH HN OOO O O O O 4 OO NN OOO HH NH H O 4 SOH NN MoO O MH H O 4 OO MN NOO S O N M 4 NOH ON HOO M O O H 4 OOH ON OOO O O O H 4 OOH NN OOM O O O N 4 NO OH OOM O O O O 4 OOH MN SOM O O H O 4 OOH HN OOM O O O O 4 OOH MN OOM O S H O 4 HO HN OOM O N H M 4 NO NN MOM OH OH M OH 4 NO OH NOM N S_ O O 4 OOH MN HOM S N O N 4 OOH HN OOM MH NM N OH 4 MO HN OOM O O N O 4 OO ON OOM M O O O 4 SO MN SOM O O H O 4 OOH OH OOM N O O H 4 MOH NN OOM O O O O 4 NOH OH OOM NH HH H O 4 OO NN MOM N O O O 4 NO NN NOM OOHHOO OOHHOO OOHHOO OOHHOO HO3mc4 oznO OH OOIHIH OOOIHOM .H? O 4 HO>o .H? O 4 HO>o HMO? M HMO? M OZ n O Ho HOQESZ .HMHOH> HOOHO OGHOOOOO 4 HO>o 4 HO>O MO? u 4 m4 OO4 m.uomnnsm HOO MHOHOO Hom mucHom .OHUO4 .HMHOH> .OOOO .>HHO OOOOHHGOOIIO OOOHO BIBLIOGRAPHY Accident Facts. Chicago: National Safety Council, 1965. Baker, J. S. "Claims Morons Make Best Drivers," Cited by New York Times, July 18, 1952. Bellamy, H. A Community Renewal Program for Lansing, Michigan. East Lansing, Michigan: Michigan State University, 1963. Brody, L. Personal Factors In Safe Operation of Motor Vehicles. New YOrk: New York University, 1947. Brown, C. W. and Ghiselli, E. E. "Factors Related to the Proficiency of Motor Coach Operators," Journal of Applied Psycholoqu(l947), XXXI, 477-479. Buros, O. K. The Fifth Mental Measurements Yearbook. New Jersey: Gryphon Press, 1959. Cantor, G. H. and Stacey, C. L. "Manipulative Dexterity in Mental Defectives," American Journal of Mental Deficiency (19511 LVI, 401-410. Case, H. W., Reiter, I., Feblowicz, E. A., and Stewart, R. G. The Habitual Traffic Violator. Instruction of TranSportation and Traffic Engineering, University Of California, 1956. Conger, J. J., Gaskill, H. S., Glad, D. D., Massell, L., Rainey, R. V., and Sawrey, W. L. (ed.). "Psychological and Psycho-Physiological Factors in Motor Vehicle Accidents," Accident Research. New York: Harper-Row, 1959. Dixon, W. J. and Massey, F. J. Introduction to Statistical Analysis. New York: McGraw-Hill, 1957. English, H. B. and English, A. C. A Compgehensive Dictionary of Psychological and Psychoanalytical Terms. New York: Longman's Green, 1961. 96 97 Eno. Personal Characteristics of Traffic-Accident Repeaters. Saugatuck, Connecticut: The Eno Foundation for Highway Traffic Control, 1948. Goldstein, L. G. Human Variables in Traffic Accidents. Washington, D.C.: National Academy of Sciences-National Research Council, No. 31, 1962. Gutshall, R. W. "Can He Be Taught To Drive?" Safety Education. Chicago: National Safety Council, November 1963. Hakkinen, S. Traffic Accidents and Driver Characteristics. Helsinki Finland's Institute of Technology, 1958. Harvard Medical School. Research on Fatal Highway Collisions. Papers, 1961-62. Hollingshead, A. B. and Redlich, F. C. Social Class and Mental Illness. New YOrk: Wiley & Sons, 1958. Howe, C. E. "A Comparison of Motor Skills of Mentally Retarded and Normal Children," Exceptional Children (1959), XXV, 352-354. Kulcinski, L. H. "Relation of Intelligence to Learning of Fundamental Muscular Skills," Research Qperterly of American Association of Healthy_Physical Education and Recreation (1945), XVI, 266-276. Levonian, E., Case, Ha W., and Gregory, R. "Personality and Biographical Variables in Relation to Driving Item, Response," Highway Research Board, NO. 79, 1963. McGuire, F. I. "A Psychological Comparison of Accident- Violation Free and Accident-Incurring Automobile Drivers," Naval Medical Field Research Laboratory , North Carolina (1955), VI, 1-26. Michigan Vehicle Code. Compiled under supervision of the Secretary of State, Lansing, Michigan, 1961. Moffie, D. J., Symmes, A., and Milton, C. R. "Relation Between Psychological Tests and Driver Performance," National Research Council, Washington, D.C., 1952. Pappanikou, A. V. and Bowman, P. W. "Driver Education-- Asset or Liability?" American Journal of Mental Deficieney (1959), LXIII, 662-666. 98 Pappanikou, A. M. and Bowman, P. W. "First Results of a Residential Schools Driver Education Program," American Journal of Mental Deficiency ' (1960), LXV, 194-198. Personal Research in the Army VI. "The Selection of Truck Drivers," by Staff, Personnel Research Section, Classifi- cation and Replacement Branch, The Adjutant General's Office, Psychology Bulletin (1943), XL. Penn, H. S. Causes and Characteristics of Single Car Accidents. Part Three and Part Four, Department of California Highway Patrol, 1965. Ross, H. L. "Traffic Law Violation: A Folk Crime," Social Problems (1961), VIII, No. 3. Scheffe, H. The Analysis of Variance. New York: John Wiley & Sons, Inc., 1959. Selling, L. S. and Canty, A. Studies on the Problem Driver. City of Detroit, Michigan, 1941. Traffic Code. By order of the City Council, Lansing, Michigan, 1958. Winer, B. J. Statistical Principals in Experimental Design. New York: McGraw-Hill, 1962. "IIIIIIIIIIIIIIIIIIIIIIS