The purpose of this grant is to analyze data collected in the Ituri Forest on the early social interactions of Efe (Pygmy) infants and the quality of their attachment to their mothers. The data to be used are naturalistic observations of infants' daily activities and social interchanges made at 1 week, 3, 6, 9, and 12 months, and the observations of the quality of attachment to their mothers as assessed in the Ainsworth Situation at 1 year of age. These data are of special importance to bio-evolutionary theories of the development because the Efe are hunters and gatherers and because pilot work has documented an extensive multiple caretaking system in the first year of life.