Is a life of crime hereditary? New research suggests that criminal behaviour could be 'all in the genes'



Rogue gene: MAO-A has been identified as being able to break down chemicals in the brain which cause aggression

Turning to crime is in the genes, according to new research carried out in the US.



A study of young men and women who had been adopted as children found they were up to four and a half more times to have been in trouble with the police if one of their natural parents had a criminal record.

The fact that their natural parents are having such a huge effect on their behaviour despite having little or no input in their upbringing clearly shows the influence of genetics.



And it suggests that while criminals can be bred, they can also be born.

The intriguing finding comes from a large-scale study of American adoptees.

More than 250 young men and women were first questioned when in High School and then periodically interviewed for the next 13 years.

When they reached their mid-20s and early-30s, they were asked if their natural parents had any sort of criminal record and if they had ever been in trouble with the law themselves.

Young men and women who had a biological parent who had been arrested at some point were up to 4.5 times more likely to have been arrested themselves than those whose natural parents were law-abiding, the Florida State University study found.

The influence of genetics did not end there. A jailed biological parent also dramatically raised the risk of the child having spent time in prison or a young offenders institution.

And the more times the biological parent was in trouble with the law, the more problematic the child was likely to be, according to the journal Biological Psychiatry.



Dr Kevin Beaver, the study’s author and a criminologist, concluded: ‘Adoptees who have a biological father or a biological mother who have been arrested previously are significantly more likely to be arrested, sentenced to probation, incarcerated and arrested multiple times.’

Genes implicated in violence anti-social behaviour include one called MAO-A which makes an enzyme which breaks down chemicals in the brain linked to aggression.

Rogue versions of MAO-A and other similar genes have previously been found to have the strongest effect when paired with a problematic upbringing.

With repeat offenders responsible for a disproportionate amount of crime and heartache, the findings have important implications.

Glimpse of the future? The 2002 film Minority Report was based around the idea of preventing crimes before they happened

For instance with genes only thought to be responsible for 50 to 80 per cent of a person’s propensity towards anti-social behaviour, the research raises the possibility that adoptees whose birth parents have a criminal past could attend classes aimed at staving off problems later in life.

The adoptive parents could also receive parenting lessons.

In an unrelated study, children whose mothers received regular home nurse visits during pregnancy and until the child’s second birthday were up to half as likely to be arrested by the age of 15.

The number of convictions fell by up to 80 per cent and they also smoked and drank less and had fewer sexual partners.

The science also raises the possibility of genetic testing being used to single out future criminals, potentially allowing them to be arrested before they break the law, as portrayed in the 2002 Tom Cruise film Minority Report.

But the involvement of hundreds, or even thousands, of genes in behaviour, means that such a test will remain in the realms of fiction for years to come, says Dr Beaver.