DEVELOPMENT AND SOCIALIZATION OF PHYSICAL AGGRESSION IN VERY YOUNG BOYS.

The expression of physical aggression is normative in early child development; it peaks in the second year of life, with steep declines for most children by the third and fourth years as children learn alternatives to aggression. Some children, however, fail to demonstrate declines in aggressive acts, and many of these are boys. The current review uses a dynamic systems (DS) approach to identify early individual and contextual factors that may dynamically influence trajectories of aggression as a characteristic way of engaging within communities and relationships. Within the DS framework, we focus on the parent-infant relationship as central to the development of adaptive emotion-regulation capacities of the infant and young child. Biological sex differences that may influence this early relationship are highlighted, as is the influence of contextual processes such as family violence. Clinical implications suggested by both the empirical and theoretical literatures are then described.