The ethological explanation of aggression

• Adaptive function of aggression

  • Ethological explanations - Main function of aggression is adaptive
  • Aggression is beneficial to survival
  • Establish dominance hierarchy - Male chimp using aggression to climb up hierarchy

  Pettite et al: Studies play groups of young children + Observed how aggression played a role in the development of children's dominance

  • Conclusion - Adaptive - Dominance over others brings benefits e.g. power
• Ritualistic aggression

  • Series of behaviours carried out in a set order

  Loren'z observations:

  • Little physical damage
  • Ritualistic signalling e.g. Displaying claws or facial expressions
  • Intra-species aggressive confrontations end with appeasement displays - Acceptance of defeat
• Innate releasing mechanisms and fixed action patterns

  • Innate releasing mechanisms (IRM) - Built-in physiological process or structure e.g. neurones
  • Environmental stimulus trigger IRM - Release specific sequence of behaviours aka. fixed action pattern (FAP)
• Innate releasing mechanisms and fixed action pattern - Lea, six main features of FAP:

  1. Stereotyped
  2. Universal - Found in all species
  3. Unaffected by learning
  4. Ballistic - Inevitable course that cannot be altered
  5. Single-purpose
  6. Response to an identifiable specific sign stimulus
• Research into IRMs and FAPs

  Method:

  • Male sticklebacks - Male entering territory they display aggressive behaviours initiated (FAP)
  • Present to wooden models of different shapes

  Findings:

  • Red spot - Attack / aggressive display
  • No red spot - No aggression even if realistic
  • FAP - Once triggered always ran its course
• Evaluation of ethological explanation of aggression - Supporting research

  • Evidence that their is an innate basis - MAOA gene + Activity of the limbic system
  • Ethological explanation - Argues aggression is genetically determined and heritable

  Strength: Validity of the EE - Genetic and physiological basis of aggression
• Evaluation of ethological explanation of aggression - Cultural differences in aggression

  Nisbett: North-South divide in USA homicide rates

  • Killing more common with white southern males than northern

  Conclusion - 'Culture of honour' - Response to impulse aggression is a learned social norm

  Limitation: Cant view aggression as instinctive - Culture overrides this
• Evaluation of ethological explanation of aggression - Evidence against ritualistic aggression

  Goodall: Chimps in Tanzania

  • Four year war - Male chimps systematically slaughtered opposition
  • Coordinated and premeditated
  • Continued despite signals that the opposition was defenceless - Did not inhibit aggression

  Limitation: Real-life cases not supported by the EE