A central principle to a systems perspective is that no one single factor, process, or multifactor interaction can be understood outside of its immediate and secondary contexts. As such, the application of a systems approach to the study of children’s social-cognitive functioning must include an analysis of all microscopic and macroscopic systems. A systems approach to social information processing in youth would thus be premised on the idea that development within the microsystem of social cognition does not occur independently of activity outside the cognitive realm. Five levels of the social cognition system are identified: long-term memory, working memory, on-line schematic processing, on-line conceptual processing, and perception. An idea central to the systems perspective is that these levels of the social cognition system exist in a reciprocal relationship to one another in that the components are continually interacting with each other across the system levels and throughout the developmental course. The author briefly discusses how a systems approach could inform the research into proactive versus reactive aggression processes in children by providing a link between the traditional dichotomies of: (1) controlled and automatic modes of processing, and (2) proactive versus reactive mental operations. Figure, footnotes, references