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…

Comparisons are used in this paper to identify improvements in mortality and morbidity experiences over time, to identify new environmental hazards, and to emphasize the potential for improvement. The comparisons are presented in the full belief that racial variations are fundamentally socioeconomic variations. Efforts are also made to identify…