This study investigated whether children oversized at birth, like those undersized at birth, have an increased chance of mental subnormality. Subjects were 4-year-olds born of urban disadvantaged white mothers whose average education was 10.8 years. Stanford-Binet intelligence scores of the subjects were compared to their birth weights. Between…

In an effort to isolate the emergence and causes of social class differences in intellectual performance, this longitudinal study was undertaken as a follow-up on a cross-sectional study that yielded no social class differences on the Cattell Infant Intelligence Scale for 12-, 18-, and 24-month-old black children. In the present study, 89 children…