E| VEN taking an extremely crude index of school achievement, that of grade placement, for every age level the average grade of middle-class urban children is higher than that of lower-class children. (See Tables 1, 2, and 3.) These differences can be observed at 7 and 8 years of age as well as at 17. Apparently whatever produces the difference starts operating to differentiate lower-class from middle-class children from the early grades. Another way of looking at class selectivity of the educational process is to observe the proportion of lower-class boys in high school a generation ago (Tables 4 and 5) or in college today.' Why are middle-class children more successful in their studies? Why do lower-class children drop out at younger ages and complete fewer grades? One hypothesis is that school teachers are middleclass in their values, if not in their origins, and penalize those students who do not exhibit the middle-class traits of cleanliness, punctuality, and neatness or who do exhibit the lower-class traits of uninhibited sexualtty and aggression.2 Some social scientists believe that lower-class children, even though they may have the intellectual potentialities for high levels of academic achievement, lose interest in school or never become interested because they resent the personal rejection of their teachers. Such rejection is, they say, motivated by the teachers' mistaken notion that lower-class children are deliberately defying them. Davis and Havighurst show that children are the prisoners of their experience and that lower-class children behave the way they do, not because of any initial desire to defy school authorities, but rather because of their lower-class childhood training.' According to this hypothesis, teacher rejection makes the lower-class boy resentful and rebellious. His attitude is, If you don't like me, I won't cooperate. Unfortunately for him, however, school achievement is related to later occupational advancement. Failure to cooperate with the teacher cuts off the lower-class boy from a business or professional career. Professor August Hollingshead describes what happens to lower-class boys from a small town in Illinois who withdraw from school to escape the psychic punishment meted out by the teachers and upper-class children.