In this chapter we will summarize the problems of aggression and their relationship to gender and maturation. We will first discuss aggression as a normative behavior and examine gender differences and their relationship to puberty. We will then focus on psychopathological forms of aggression, such as disruptive behavior disorders, again relating them to gender and pubertal development; we will conclude with a discussion of gender differences in delinquency. In each of these subsections, we will cite research that approaches the topic from an experimental, naturalistic, and clinical perspective.

Aggression as a normative behavior: gender differences

To understand gender differences in aggression and violence, one can take a developmental approach and examine the presence of aggression through the various life stages (Loeber and Hay, 1997). During infancy signs of frustration and rage can be observed, though significant gender differences cannot be detected. Research conducted by Weinberg and colleagues (1999) found gender differences in the emotional expressiveness among infants, although it is unclear if these differences are precursors to aggression. Infant girls were able to regulate their emotional states better than infant boys, who were more likely to show anger. During the toddler stage minimal gender differences were found to exist, but research findings are conflicted.