genetic factors in aggression AO3

Question 1

strength of the role of genetics factors in aggression - research support

Answer 1

• support for the role of the MAOA gene in aggression
• research from bruner et al and lea and chambers shows that the low activity variant of the MAOA gene is associated with greater aggression.
• mertins et al (2011) found that the converse is also true. men with low-activity and high-activity variants of the MAOA gene took part in a money distributing game. men with the high-activity variant were more co-operative and made fewer aggressive moves than the low-activity participants.
• this finding supports the relationship between MAOA gene activity and aggression.

Question 2

COUNTERPOINT of strength of the role of genetic factors in aggression - research support

Answer 2

• however, the study of mertins et al also showed that non-genetic factors are crucial.
• they found that even participants with the low-activity MAOA variant behaved co-operatively rather than aggressively when they were made aware that others in the study were behaving co-operatively.
• knowledge of a social norm partly determined how aggressive or co-operative MAOA-L participants were.
• therefore, genes are influenced by environmental factors that are at least as important in aggression.

Question 3

limitation of the role of genetics factors in aggression - problems with twin studies

Answer 3

• twin studies may lack validity
• in every part of twins, both individuals share the same environment. however, dz twins may not share the same environment to the same extent as mz twins.
• we assume they do and this is called the equal environments assumption. but the assumption might be wrong because one aspect of the environment is the way twins are treated by others.
• mz twins are treated similarly, especially by parents. dzs are treated in less similar ways.
• this means that concordance rates are inflated and genetic influences on aggression may not be as great as twin studies suggest.

Question 4

limitation of the role of genetics on aggression - multiple genetic influences (limitation)

Answer 4

• limitation of MAOA gene-aggression link is that there are probs other genes involved in aggression
• stuart et al found that intimate partner violence in men was associated with the low activity form of the MAOA gene but also with serotonin transporter gene (5-HTT). so, it is a combination of the 2 genes that is linked with IPV.
• as well as this, vassos et al conducted a meta analysis and found there wasn’t an association between a single gene and aggression
• therefore, it is very likely that thousands of genes interact in complex ways to determine aggressive behaviour. this means the complexity of the gene-aggression link is ignored and the MAOA gene-aggression link is simplistic