This collection of papers represents an extension of analytic approaches and concepts from animal social ethology to the study of activities among stable groups of young children. A major emphasis of this research was on the description of organizational patterns in social behavior observed during periods of free play. The papers are: (1) "An Introduction to Ethological Perspectives on Preschool Social Organization;" (2) "Social Conflict and Peer Group Status;" (3) "Peer Attachment and Affiliative Subgroups;" (4) "Giving, Helping and Cooperation: The Beginnings of Reciprocal Altruism;" (5) "Differences in Play as a Function of Social Roles Within the Peer Group;" (6) "The Emergence of Social Structure in Normal and Clinical Groups of Unacquainted Children;" (7) "The Development and Stabilization of Social Interaction in a Clinical Peer Group;" and (8) "Discussion of Ethological Perspectives on Child Development." (MS)