Children in transition from infancy to childhood are learning rapidly about their social environment and social relationships. Their social initiations and communications are increasing in number and variety, and their level of understanding of such events is changing as well. The intricacies of giving, defending, asserting, receiving, aggressing, and negotiating begin to appear in the stream of their behavior. Individual children are soon distinguishable in their patterns of social interaction. Investigators have not found it easy to identify how prosocial and antisocial behaviors emerge along a developmental trajectory and how they become organized into adaptive and maladaptive patterns. Our interest here is in investigating patterns of development as well as individual differences in altruistic and aggressive behaviors in young children.

The concentration of research with regard to altruism and aggression has been on middle and later childhood (see reviews by Radke-Yarrow, Zahn-Waxler and Chapman, 1983, on altruism, and by Parke and Slaby, 1983, on aggression). When these behaviors have been observed in the 2-and 3-year old, there has been a tendency to attribute less than full intentionality to them. Rather, they have been conceived as random, incidental acts independent of later patterns of social behaviors. As research of recent years has greatly elaborated our knowledge of infants' and young children's social sensitivities and capacities, there has been greater interest in the early manifestations of altruism and aggression (e.g., the work of Rheingold, Hay, & West, 1976; Yarrow and Waxier, 1977; and Zahn-Waxler and Radke-Yarrow, 1982, on prosocial behavior; of Hay & Ross, 1982, on aggression) and in the predictive value of these early behaviors as precursors of later social behaviors.