book aaa genetic aggression notes

Question 1

MAOA genes caucasians

Answer 1

The MAOA gene has been nicked nicknamed warrior gene because of research by rod lea and chambers which showed that the MAOA-L variant was possessed by 56% of New Zealand Maori men compared with 34% caucasians historically the Maori people have had a reputation for being ferocious warriors hence the nickname

Question 2

twin studies

Answer 2

Several twin studies have suggested that heritability accounts for about 50% of the variance in aggressive behaviour. For example Emil Coccaro studded men who were either MZ or DZ. concordance rates of 50% for the MZ twins and 19% for DZs. The corresponding figures for verbal aggression were 28%MZ and 7% for DZ

Question 3

meta anaylis

Answer 3

Rhee and Walkman carried out a meta analysis of adoption studies of direct aggression and antisocial behaviour, a prominent feature of which is aggressive behaviour. They found that genetic influences accounted for 41% of the variance in aggression, more or less in line with findings from twin studies

Question 4

Link between MAOA-L and MAO_A enzyme

Answer 4

The link between MAOA-L and aggression was further cemented by Brunner et al. They studied 28 men from a large Dutch family who were repeatedly involved in impulsively aggressive violent criminal behaviours such as rape attempted murder and physical assault. These men had abnormally low levels of the enzyme MAO-A as well as the MAOA L gene variant