The study compared three groups: those whose parents had been openly aggressive toward one another; those whose parents, although not generally aggressive, used physical punishment in their childrearing; and those whose parents were neither generally aggressive nor users of physical punishment. The groups were similar in the proportion living in deteriorated areas, in parental supervision of after-school activities, and in parental showing of affection and concern for their welfare. Results indicated that the men reared by aggressive parents appear to have become aggressive and expressive adults. More than half had records for committing serious crimes. Men reared by nonaggressive parents who used punitive discipline appeared to be self-centered, taking pride in their accomplishments and not contributing their time to benefit others. Findings suggested that the transmission of aggression is promoted through the example of parents, whose conflict serves as a model, and that parental aggression directed toward children teaches children to be more concerned about themselves and less concerned about others. Tables, notes, and 17 references.