Friday, November 26, 2010
New research suggests that criminal behavior could be genetic
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 behavior despite having little or no input in their upbringing clearly shows the influence of genetics. The intriguing finding comes from a large-scale study of 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. Genes implicated in violence anti-social behavior 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. Genes are thought to be responsible for 50% to 80% of a person’s propensity towards anti-social behavior.