Aggressive behaviour in childhood can often lead on to bad behaviour in adolescence and adulthood. For most people aggression is most common during early childhood. It increases rapidly from one to three and then declines after that. If people carry on being aggressive after three that is a strong indication that they will behave badly later. There are a number of programmes aimed at reducing aggression in young children and these have been shown to improve parenting practices and reduce, or prevent, bad behaviour. Researchers from New York University looked into the links between one such parenting programme, parenting practices and aggression. They studied 92 families where one child had already been in trouble with the law and studied the effect of the Incredible Years Series programme on their younger siblings who were aged between 2 3/4 and 5 1/4. Half the families took part in the programme while the other half formed a control group. The intervention was found to have a significant effect over time in reducing aggression which increased in the control group. Improved parenting practices were found to be responsible for 40% of the improvement caused by the parenting programme. Harsh parenting, which increased aggression, and responsive parenting, which decreased it, were found to be most closely linked to aggression. Stimulating parenting (which decreased aggression) was less-closely, but still significantly linked to a reduction in aggression.
Brotman, Laurie Miller ... [et al] - An experimental test of parenting practices as a mediator of early childhood physical aggression Journal of Child Psychology and Psychiatry March 2009, 50(3), 235-245