The neurobehavioral organization of Efe (pygmy) infants

The neurobehavioral organization of 16 Efe Mbuti (pygmy) infants was examined over the first weeks of life using the Brazelton Neonatal Behavioral Assessment Scale. Mbuti infants are the smallest well-grown, full-term infants in the world, i.e., length and weight below the 10th percentile but ponderal index above the 50th percentile. The Efe infants are a relatively isolated population that allows for an evaluation of ethnic differences in newborn behavior; their small stature permits the examination of the relations among size, neurobehavioral organization, and morbid processes. The neurobehavioral organization of the Efe was compared with three groups of full-term infants: two full-statured, well-grown groups of infants, one African, one United States; and a group of symmetrically growth-retarded infants whose weight and length were proportionally compromised in utero. The behavioral organization of the Efe infants was found to be similar to the neurobehavior of the well-grown infants and superior to the group of growth-retarded infants. No unique neurobehavioral features were found compared with the other groups. These findings suggest that neurobehavioral organization has a universal form and that expected small size per se does not compromise infant behavior.