Genetics and bad parenting link to criminal behaviour

NZ Herald April 11, 2008
Whether a criminal teenager turns into a violent adult or grows out of crime may be related to how low his ears are set or the types of food he was given as a child. New Zealand research shows antisocial behaviour in young adults can be written into their genetic code, and made worse by bad parenting. Indicators that an antisocial child may turn into a life-long violent criminal can be picked up in kindergarten, says research summarised in this week’s New Scientist magazine.

Of the 535 males and 502 females born in New Zealand in 1972 and 1973 who were signed up at birth to Otago University’s Multidisciplinary Health and Development Study, those who dabbled in crime as a teenager can be divided into two clear groups, said Terrie Moffitt from the Institute of Psychiatry in London. The more common type took up petty crime in adolescence, keen to impress “badass” friends, she said. But the more problematic type had biological predispositions to behaviour problems, the signs of which could be picked up as young as 3 years of age. These children – more often boys – tended to have a low IQ, poor language skills, and were often diagnosed with attention-deficit hyperactivity disorder. Minor physical anomalies such as low-seated ears or furrowed tongues – possibly a sign of poor neural development or damage – could also be signs. Combined with bad parenting, poverty or abuse, these children were at greater risk of turning to a life-long criminal career, she said.