The earlier aggression is established, the worse the long-term outcome tends to be. Male aggressive behaviour is highly stable as early as age two. In boys, the stability of aggression increases from middle childhood to adolescence. Indeed, serious antisocial behaviour is highly resistant to change in school-age children and adolescents. Although antisocial tendency is a stable construct, its social expression varies with age.
Antisocial children grow up to become antisocial adults who go on to raise antisocial children.
This overall picture is confirmed by the Dunedin study which followed a cohort of children born in 1972 through until age 21. Compared to the lower risk group it was found that the at risk group had more than twice as many people with two or more criminal convictions and three times as many people with antisocial personality. Those of the at risk group included robbery, rape and homicide. Recent neurological research suggests that an infant s brain may be permanently altered if the child is brought up in an environment where it experiences intense stress, emotional neglect, chronic parental depression and abuse. By age three, remarkably, the number of synapses increases to 1,000 trillion.