Genetic factors

• genes

  can determine levels of testosterone

  determine physiology of the brain and can determine the pathway between limbic system and frontal cortex
• investigating

  use of twin, family and adoption studies

  to manipulate varibales- animal studies are used
• MAOA genes

  involved in processing neurotransmitters including serotonin

  MAOA gene controls the production of MAOA enzyme

  some versions have lower levels of MAOA and therefore less serotonin causing a link to aggressive behaviours
• gene-environment interactions

  evidence suggests individuals inherit a predisposition to being aggressive

  which is then mediated by the environment

  e.g MAOA gene and then an environmental cause such as childhood trauma sexual abuse first 15 years of life

  functional outcome depends on the environment
• summary

  genes can determine other bio factors

  MAOA warrior gene controls production of mana enzyme controlling production of serotonin

  aggression increased if versions of the gene cause lower levels of MAOA enzyme
• evaluation

  strengths- research Brunner et al

  5 male members in Netherlands aggressive beahviours- found faults in their MAOA gene

  weakness- hard to isolate genetic factors

  problems with measuring- self-reports, parent and teacher reports and observations