Aggression

Aggression

1. Neural mechanisms

   • The limbic system
     • Most important limbic structure is the amygdala, with a strong link between a stimulated amygdala and aggressive behaviour.
   • Serotonin
     • Denson et al: Decreased levels of serotonin associated with more impulsive aggression.
   • Evaluation
     • Role of other brain structures - Brain regulation of aggression is complex and involves multiple structures, i.e. amygdala and OFC
     • Effects of drugs on serotonin - Berman et al: Drug to enhance serotonin reduced aggression in lab-based game, compared with placebo.

2. Hormonal mechanisms

   • Testosterone - Animal studies: increased testosterone linked with higher aggression levels (and opposite in castration studies)
   • Evaluation
     • Josephs and Mehta: Losers of a challenge game more likely to rechallenge if their testosterone levels rose - supports bisocial model of status.
     • Carre and Mehta: High testosterone only leads to aggression when cortisol is low - supports dual hormone hypothesis.
     • Much research is correlational so unclear if factors are causes or effects of aggression.

3. Genetic factors