Although interest in the possible harm of malnutrition on mental function in humans had received sporadic attention in several countries since the 1920s, the value of systematic investigation belongs to the present decade.1-4 One of the main reasons for the apparent lack of interest in the past probably arises from awareness that infant malnutrition as it is commonly encountered is invariably associated with other factors that are in themselves capable of delaying or arresting mental growth and development. Since most of the individuals susceptible to malnutrition belong to the underprivileged segments of society, it was believed that differences in mental performance between well-nourished and malnourished subjects were an expression of social class. Although it was recognized that behavioral disturbances were prominent features of malnutrition, and during the development of chronic malnutrition from the mild-moderate to the severe forms failure to re