Sex crimes may run in a family’s male genes

THE brothers of men convicted of sex offences are five times more likely than average to commit similar crimes, according to researchers.

They also found the sons of fathers with a criminal record for sex offending were nearly four times more likely to be convicted of such crimes.

The biggest study of its kind suggests sex offending could run in the family along the male genetic line.

The findings show that 40 to 50 per cent of the differences in risk between close relatives of offenders and men from the general population were genetically driven.

But the researchers stressed that this did not mean a man with a brother or father convicted of rape would inevitably follow in their footsteps.

Lead scientist Professor Niklas Langstrom, from the Karolinska Institute in Sweden, said ‘ It’s important to remember that it’s nothing mystic.

‘Of course you don’t inherit in some kind of automatised robotic

‘Substantial influence’

way so that you will grow up to be a sexual offender.’

The scientists studied data on all men convicted of sexual offences in Sweden between 1973 and 2009. Rates of sexual offending there are similar to those in the UK.

Of the 21,566 offenders, nearly half had convictions for adult rape or child molesting. Other crimes included possession of child pornography, indecent exposure and sexual harassment.

In terms of absolute risk, being closely related to an offender only led to a small increase in the chances of committing a sexual crime. Just 2.5 per cent of brothers of sex offenders were convicted of similar crimes, compared with 0.5 per cent of men in the general population, according to the study reported in the International Journal of Epidemiology.

Co- author Professor Seena Fazel, from Oxford University, said: ‘We are definitely not saying that we have found a gene for sexual offending.

‘What we have found is highquality evidence from a large population study that genetic factors have a substantial influence.’