The findings revealed strong negative correlations between the frequency of delinquent acts (violent and nonviolent) and the temperance component of psychosocial maturity. Logically, youths that possessed a greater ability to control their impulses and modulate their behavior reported committing fewer delinquent acts of both types. Perspective also was negatively related to the commission of nonviolent delinquent acts but less strongly than temperance. Responsibility was unrelated to the frequency of delinquent acts. Temperance was also the strongest factor associated with adolescents' age of onset for nonviolent behaviors, and whether they committed these acts alone or with peers. Youths with poor impulse control reported committing nonviolent acts at a younger age and committing all delinquent acts more often with peers than did those with more developed internal regulation. Regression analyses confirmed that the temperance factor was the significant maturity and variable in predicting violent, nonviolent, and total delinquent behaviors for boys and holds promise as a significant predictor of similar behavior among girls. Participants were a sample of 106 male and 30 female adolescent youths recruited from southwestern juvenile detention or boot camp facilities whose ages ranged from 11 to 17 years old. Data were collected over a 12-month time period. Tables, references