This study used longitudinal data on young male offenders in California in order to examine trajectories of criminal behavior from childhood to adulthood, with a focus on the main and interactive effects of age at first arrest and completion of high school.
The study found that the aggregated age-crime curve showed that the number of arrests increased dramatically in late teens and gradually leveled off with age. Offenders who had been arrested at a younger age tended to have a steeper cumulative growth in crime trajectories. This suggests that early interactions between adverse environments and biological predisposition limit alternatives to a criminal lifestyle. Although the main effect of completion of high school education did not reach statistical significance, there was a significant interaction between educational attainment and age at first arrest on a nonlinear slope of crime trajectories. This suggests that the pace of committing offenses over time was substantially slowed down for late starters in crime who completed high school. Probing the mechanisms for how finishing high school facilitates late starters' desistance from crime is an important future topic for research. For this study, 2,350 offenders were selected from the 4,146 who participated in the Wenk Study, a longitudinal study of a sample of young male offenders admitted to the jurisdiction of the California Youth Authority in Tracy, CA, January 1964 to December 1965. Those selected were either 19 or 20 years old at the initial assessment, because they were the two largest cohorts in the dataset older than 18 years old. The variables measured were the cumulative frequency of arrests ("lifetime" cumulative frequency of arrests and the cumulative frequency of arrests between ages 20 to 38), age at first arrest, completion of high school, cognitive ability, and self-control. 1 table, 4 figures, and 80 references