You are here

Propensity to be violent develops mainly through experience in the home to age 3

Pathways to crime

The early years are critically important to children’s later social development, their wellbeing and their ability to succeed in life. Focusing just on the social development aspect, pathways to crime are often laid down by the age of 2 or 3. The result can be aggressive personalities for life. Studies consistently show that aggression and violence are stable character traits (1). The earlier aggression is established, the worse the long-term outcome tends to be (2). Male aggressive behaviour has been found to be highly stable as early as age 2. Research by Professor Richard Tremblay at the University of Montreal has shown that the 1 in 6 children who are most aggressive at ages 2 – 3 are already 10 times more aggressive than the 1 in 3 who are most peaceful. (3)

After age 3, the habit of violence is increasingly difficult to shift. Three quarters of aggressive 2-year olds are still aggressive at 5; thereafter it is an even more stable trait (4). Serious antisocial behaviour is highly resistant to change in school-age children (5). To succeed in discouraging aggression in schoolchildren, support and corrective action needs to begin long before they are in school.

The Dunedin Study

Compelling evidence of the early age at which the roots of violence are firmly planted comes from the New Zealand Dunedin Study, in which nurses could predict future criminal tendencies 18 years in advance (6).

Every child born in Dunedin in 1972 has been monitored from birth, and assessed every two to three years on a variety of health, social, behavioural and environmental measures. In the course of this monitoring, nurses identified an at-risk group of 3-year olds on the basis of 90 minutes’ observation; these children were restless and negative, and lacked persistence and attention.

At age 21, males in the at-risk group were compared with other 21 year olds: 47% abused their partners (compared with 9.5% of others); three times as many had antisocial personality; two and a half times as many had two or more criminal convictions. 55% of at-risk offences were violent (compared with 18% of others). The at-risk group not only committed many more violent offences, but also much more severe ones, such as robbery, rape and homicide.

Fewer of the females became conduct-disordered but, where they did, 30% of the at-risk group had teenage births (the others had none) and 43% were in violent, abusive relationships (7). The authors conclude:

Immature mothers, with no strong parenting skills, and violent partners, have already borne the next generation of ‘at risk’ children.


In recent years WAVE has come across more and more research pointing to the importance of intervention beginning during pregnancy, rather than waiting until after the birth of the child. For instance we now know that maternal smoking in pregnancy, taken on its own, can more than double the risk that the child will become a persistent criminal (8). 


(1) Huesmann et al, 1984

(2) Rutter, Giller & Hagell, 1998; van der Kokl et al, 1993

(3) Cummings, Iannotti & Zahn-Wexler, 1989

(4) Eron, 1997

(5) Kazdin, 1987; Tolan & Gorman-Smith, 1997

(6) Caspi et al, 1996

(7) Moffitt & Caspi, 1998

(8) Räsänen et al, 1999