Outline and evaluate neural mechanisms in human aggression

Outline and evaluate neural mechanisms in human aggression

1. Serotonin

   • Mann ’90
     • 35 ppts given dexfenfluramine, which lowers serotonin. A questionnaire was then given that assessed hostility & aggression. The drug increased aggression in males, but not women
   • Scerbo & Raine
     • Meta-analysis of 29 studies of anti-social kids & adults. All had lower serotonin levels. It was far lower in those that were suicidal. Ppts had more impulsive behaviour, as there’s less communication between prefrontal cortex & rest of brain
   • Raleigh
     • Monkeys were given low tryptophan diets, which makes serotonin. Their aggression therefore increased

2. Dopamine

   • Lavine ’97
     • Amphetamines increase dopamine, so increase aggression
   • Beitlaar
     • Antipsychotic drugs lower both dopamine & aggression
   • Couppis & Kennedy
     • Mice learned aggression due to triggering of dopamine reward pathway

3. AO2

   • Scerbo & Raine
     • Unreliable as meta-analysis have studies full of different techniques
   • Ethical issues
     • Older studies are mostly on animals, which can’t always be applied to humans
     • Is it ethical to manipulate serotonin levels in ppts? May this not cause psychological harm?

4. IDA

   • Gender bias
     • Almost all ppts are male
   • Reductionism
     • What about individual differences? SLT?
   • Biological determinism
     • No free will in our actions? Does biological makeup cause aggression or is it just a link?
   • Real world
     • Level of determinism can be useful to develop anti psychotic drugs so can have a benefit
   • Do neural mechanisms not just give a predisposition to aggression? Some people with low serotonin may not always be aggressive