This award is for a pilot project involving two anthropology professors and one graduate student in Botswana. The project will study the economic and reproductive strategies of men in a pastoral society; interview mothers about their perceptions of sex differences in infants to try to explain a dramatic sex bias in mortality against male infants; and develop a methodology for analyzing the differences in work effort of men and women, adults and children. This pilot research is important to help the investigators develop their procedures for a large scale study of the conflict between biological goals, such as reproductive success, and culturally defined goals such as maintenance of the patrilineage. Understanding of how cultural transmission transforms biological motives is important in understanding how to maintain biological well-being.