Purpose: To assess changes in aggressive behaviors as related to progression from early to late puberty in normal adolescents.
Methods: Subjects were normal English schoolchildren. An observational cohort design was employed. Pubertal status was measured by Tanner staging. Self-reports of verbal aggression against adults, physical aggression against peers, aggressive impulses and aggressive inhibitory responses, were collected at three points in time. Analyses were performed for the entire group of 106 subjects in 1983, 77 subjects in 1985 and 70 subjects in 1987. Statistical methods included analysis of variance, regression and correlation and cluster formation.
Results: There were decreases in all aggression variables except in aggressive impulses over this time period. When analyzed by gender, boys were initially more aggressive than girls, but by late puberty all gender differences in self-reported aggressive behaviors had disappeared. When only those subjects who were evaluated at all three data collection times were grouped by similar responses on both aggression and physical variables, three clusters of boys and girls were identified. Clusters contained varying proportions of boys and girls. Cluster one (48.5% of the entire sample) was a low aggression group. Cluster two (30.3%) was a high aggression group, and cluster three (21.2%) was an intermediate aggression group. These clusters seemed to have relatively stable aggression characteristics over time.
Conclusions: These data suggest that groups of boys and girls who report similar aggression characteristics and have similar growth and pubertal characteristics can be identified. Neither gender alone, nor pubertal status alone, nor by inference, hormones alone is sufficient to explain the complex set of behaviors which are involved in aggression.