Genetic factors

• Genetic factors suggest aggression is hereditary. If the gene is inherited, the individual will be predispoed to be aggressive.
• The MAOA gene (a candidate gene) has been linked with aggressive behaviours.

  • is is responsible for the production of the MAOA enzyme which breaks down neurotransmitters in the brain: dopamine, noradrenaline and serotonin
  • the low-activity variant of this gene (MAOA-L) means low production of this enzyme so fewer neurotransmitters are broken down in the synapse, therefore higher levels of them in the synapse
• The MAOA gene is found on the X chromosome - inherited from our mother so could equal sex differences...

  • Males only have one X chromosome
  • Females have TWO X chromosomes (one from the father and one from the mother)

  If a female had one MAOA-L gene and one normal one, the normal one would have a 'protective' effect, so aggressive behaviour would be more at a normal level