individual & developmental differences

• individual difference

  brain damage & freud
• brain damage

  • similarities in people's brain structure & functioning - e.g: effect of recreational drugs in synaptic transmission such as heroin which binds to opioid receptors to trick the brain into releasing endorphins relieving pain and gives euphoria
  • differences in aggression may be due to differences in brain activation e.g: raine et al
• supporting evidence for brain damage

  • phineas gage damaged measured in modern day
  • damage was left and right PFC which causes a defect in rational decision making and processing emotion
  • explaining his sudden changes in heightened aggressive behaviour is linked to brain damage of certain areas
• freud

  • childhood experiences throughout development of personality lead to individual differences in adult personality - e.g: overdeveloped ID leads to selfish & demanding personality, an overdeveloped superego leads to adult personality which is overly moralistic and judgemental
  • overdeveloped ID may lead to aggression due to desire to fulfil needs immediately so may be aggressive to get what they want, overdeveloped superego lead to a person being aggressive as they are able justify behaviour to themselves as being moral or just
• supporting freuds ideas

  • freud theory explains why some people have hot blooded and cold blooded aggression
  • hot blooded - impulsive and angry serving no purpose other than personal satisfaction & cold blooded - actions are deliberate serving a purpse (ego controlling id’s impulse)
  • explanation for aggression fit reality of aggressive behaviour
• developmental psychology

  hormones & evolution
• hormones

  • affect how we develop - testosterones needed to produce male features e.g: facial hair, deeper voice
  • testosterone leads to more aggressive, irritable behaviour
  • cortisol is secreted to protect the body from effects of stress and may be responsible for regulating aggression from stress therefore inhibits aggression
• supporting evidence for hormones

  • research shows testosterone leads to aggression
  • motelico-heino edwards and rofi had male rats castrated so unable to produce testosterone but when given the rats testosterone injections after castration showed aggression
  • introduction of testosterone in development increases aggression
• evolution

  • evolutionary theory suggests those most suited for survival will survive - survival of the fittest and individuals are more likely to have reproductive success and pass on advantageous genes
  • in challenging environments, aggression help ancestors gain territory, resources, status
  • genetic mutations will occur within a species which lead to adaptive advantage leading to those genes being more likely to be passed on to the next generation
• strength - evidence for evolution

  • research evidence
  • chester (2015) took a sample of female saliva samples and found a positive correlation between a low functioning MAO' warrior gene' and aggression levels
  • aggression has been shaped by the processes of natural selection and evolutionary advantages of exhibiting this behaviour can explain why it is present in society