Corporal punishment of young children and subsequent aggressive behaviour is the focus of a new study by US researchers. A team from Tulane University in New Orleans has surveyed participants of the Fragile Families and Child Well-being Study (1998-2005), a population-based, birth cohort study of children born in 20 major US cities. The survey assessed 2461 responding mothers’ reports of corporal punishment, children's aggressive behaviours at age three and five years, and other demographic features and potential confounding factors, such as psychological maltreatment and neglect, maternal depression and substance use, among others. In their May 2010 online report in the journal Pediatrics, the authors say: "Frequent use of corporal punishment (ie, mother's use of spanking more than twice in the previous month) when the child was three years of age was associated with increased risk for higher levels of child aggression when the child was five years of age (adjusted odds ratio: 1.49), even with controlling for the child's level of aggression at age three and the aforementioned potential confounding factors and key demographic features." In the US, most parents approve of and have used corporal punishment to discipline children, the authors say, despite American Academy of Pediatrics advice to the contrary. But this report suggests even spanking increases the risk of child aggressive behaviour – not attributable to the host of other maternal parenting risk factors – and is further evidence against smacking young children.