Discuss genetic factors involved in aggressive behaviour
A way to study the hereditary of aggression is through twin studies. There are two types of twins; monozygotic who are identical and share all the same genes are dizygotic who are non-identical and share only 50% of genes. If there is a 100% concordance rate between monozygotic twins it suggests that share genes may be responsible for aggressive behaviour rather than the environment. Caccaro et al found that there was a 50% variance in aggressive behaviour of adult twin pairs and that it was caused by genetic factors suggesting that genetics are involved with the aggression of individuals.
Research that supports the link between ...view middle of the document...
The results suggested a strong genetic influence that count for as much as 50% of the variance in aggression suggesting that genetics influences aggression.
A genetic factor involved in aggressive behaviour is monoamine oxidase A (MAOA), which produces protein and is responsible for aggression. The gene also regulates the metabolism of serotonin as low levels of serotonin has been linked with aggressive and impulsive behaviour suggesting that there is a link between the MAOA gene and aggression.
Research that supports the link between the MAOA gene and aggressive behaviour was conducted by Brunner et al. They conducted a study on a Dutch family and found that most of the males were aggressive and violence; a large proportion of the males had been involved in serious crimes. They found that these males had low levels of serotonin and they later found a defect of the gene MAOA suggesting that those who have a defect of the gene may be inclined to aggressive behaviour implying a link between genetics and aggression.
Caspi et al attempted to look at the interaction between genes and the environment. They conducted a study linking the MAOA gene to aggressive behaviour, involving 500 male children. They discovered that a variant in the gene was associated with high and low levels of aggression. If the children had low levels and were maltreated they produced anti-social behaviour. If the children had high levels and were maltreated and low levels and not maltreated they weren’t antisocial suggesting that...