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July 26, 2004
Gene predicts agressive behavior. Bad monkey!
Republished from South Africa's Sunday Times of July 25, 2004:
The throw of the genetic dice helps to determine whether you seethe with rage or turn the other cheek, a study suggests.
Researchers have found evidence that some people inherit a genetic make-up that makes them more prone to aggression and violence.
However, the "bad behaviour gene" is only activated if people were neglected or abused as children, scientists say.
The findings add to growing evidence that the "nature versus nurture" debate is too simplistic.
Behaviour is actually influenced by a complex interaction between genes and environment, researchers say.
The research raises the possibility that babies could be screened for genetic mutations that increase the risk of excessive aggression later in life. Scientists may also develop drugs to reduce the risk of violent offending in adolescents and young adults.
Although the study was carried out in monkeys, its findings closely mirror previous research on genes and aggression in humans.
The team, led by Dr Steven Suomi of the National Institute of Child Health and Human Development in Bethesda, Maryland, looked at the links between aggressive behaviour, genes and upbringing in rhesus monkeys.
Between 5% and 10% of wild and captive male rhesus monkeys are extremely violent. They pick fights with the strongest males and turn play fights into bloodbaths.
Suomi split the monkeys into two groups.
Half were deprived of their mothers at birth and reared with their brothers and siblings for the first six months. The rest were reared naturally. The scientists then looked for a gene called 5HTT that has been linked to impulsive aggression.
The gene is involved in the way the brain handles the feel-good chemical messenger serotonin and comes in two varieties - a "short" mutation which leads to low serotonin levels, and a "long" variety leading to higher levels.
The animals that had the short "bad behaviour" version of the gene and who were separated from their mothers developed into ultra-violent monkeys, the researchers found.
However, the short version of the gene had no e ffect on the monkeys' behaviour if they were raised by their mothers.
"There is a buffering effect of good mothers," said Suomi. "It is the gene-environment inter action."
Monkeys with the longer version of the gene were placid, irrespective of whether they were separated from their mothers.
The findings highlight how good parenting can counteract the effects of bad genes.
It also helps to explain why some children grow into well- adjusted, happy and normal adults despite suffering the most appalling traumas.
Posted by canton at July 26, 2004 07:01 PM