This document, presented at a symposium on violence and aggression in America, reports a longitudinal study of environmental influences in the development of aggressive behavior. Subjects were 875 third graders when originally assessed with a peer nomination technique in 1960. High, moderate, and low degrees of aggression were identified in the…

Changes from the expected life course can arise from at least three different reasons in longitudinal work: developmental novelty, errors in diagnosis, and errors in expectation. This longitudinal study examined the social development of 220 fourth graders and 475 seventh graders over a period of 10 years with over 98 percent of the original…

Comments on research problems raised in this special issue. Suggests that recent research highlights the nature of the multiple processes underlying variability in child and adolescent adjustment. Views variability as a function of covarying influences from multiple domains, operating on specific developmental outcomes across a background of time…