The role of early aggressive behavior in the frequency, seriousness, and types of later crime.

This study reports on the relation between aggressive behavior at early school age and later delinquent activities of 1,027 subjects (517 boys and 510 girls) prospectively followed from late childhood to adulthood. The research group was a fairly unbiased age sample of children, covering most of the range of social and psychological upbringing conditions for 10-year-old children in a Swedish community. Aggressiveness was measured by teacher ratings at ages 10 and 13 years. Delinquency, defined as registered lawbreaking, was covered through age 26. There was a strong connection between both the aggressiveness ratings at ages 10 and 13 and adult delinquency for boys, with the majority of delinquents and recidivists being recruited from the early-aggressive boys. High ratings of aggressiveness were characteristic of boys who later committed violent crimes and damage to public property and generally of subjects with a diversified offense pattern. Aggressiveness was not predictive of later crime for girls until they reached the age of 13. For both sexes the relation between aggressiveness and crime was to a large extent independent of intelligence and family education. The possibility of making individual prognoses and the role of aggressiveness for the sexes are discussed.