In this study an effort was made to determine the effects upon learning of subclinical degrees of nutritional stress in an urban black ghetto. The study population index and control groups were selected from healthy babies born between 1964 and 1966 in Kansas City, Kansas. In the first part of the study, newborn anthropometric measurements and growth patterns of the two groups were compared to determine whether differences in body measurements were related to differential performance on psychological tests of mental development. In the possibly malnourished index group of children, current head circumference was found to be positively associated with performance on these tests. No such relationship was found for the control group, nor were statistically significant associations between any other anthropometric measures and psychological test performance identified. In the second part of the study, each child was considered in the context of his/her home environment. An attempt was made to identify factors associated with the child's assignment to the index or control group at birth, and with the child's nutritional environment and growth since birth. At the aggregate level of this sample, nutrition and growth were shown to be related. Differences in child growth were found to be associated with a number of environmental factors. Additional results of the study are presented in statistical form and are discussed in detail. (Author/GC)