Genetic Factors in Aggression: Evaluations

Question 1

what are the evaluations of the genetic factors in aggression?

Answer 1

• strength = research support
• limitation = complex link
• limitation = problems with twin studies

Question 2

explain the research support evaluation for genetic factors in aggression.

Answer 2

• research support for the role of the MAOA gene in aggression
• research shows that MAOA-L is associated with greater aggression
• Mertins et al found the converse is also true
• men with low-activity and high-activity variants of MAOA gene took part in a money-distributing game
• MAOA-H were more co-operative and made fewer aggressive moves than MAOA-L particpants
  = fijndings supports relationship between MAOA gene activity and aggression

Question 3

explain the complex link evaluation for genetic factors in aggression.

Answer 3

• MAOA-serotonin-aggression link is that the precise mechanism is unclear
• research linked aggression with low levels of serotonin, but MAOA-L gene causes low activity of MAO-A enzyme which leads to higher serotonin, as low activity of MAO-L doesn’t deactivate serotonin so there’s more for synaptic transmission
• people with MAOA-L variant it’s more accurate to say their serotonin levels are disrupted rather than lower or higher than normal levels
  = relationship between MAOA gene, serotonin and aggression isn’t fully understood

Question 4

explain the problems with twin studies evaluation for genetic factors in aggression.

Answer 4

• twin studies may lack validity
• in every pair of twins, both individuals share the same environment as each other
• DZ twins may not share their environment to the same extent that MZ twins share theirs
• we assume that they do = called the equal environments assumptions
• the assumption may be wrong as one aspect of the environment is the way twins are treated by others
• MZ twins treated fairly similarly, especially by parents whilst DZ twins are treated in less similar ways