Ethological Explanation

• What is the Ethological Explanation?

  The study of innate behaviours of animals in their natural environment
• What are innate releasing mechanisms?

  A biological structure or process which is activated by and external stimulus that triggers a fixed action pattern
• What are fixed action patterns?

  A sequence of stereotypical pre-programmed behaviours triggered by an innate releasing mechanism
• The ethological explanation says that aggression has an adaptive function. What are the ways in which aggression can benefit survival?

  • During conflicts the animal is rarely killed but rather forced to establish territory elsewhere. Allows species to spread out and enhance survivability
  • Allows the establishment of dominance hierarchies. Males compete the sexual attention of females
  • Petit et al - studied groups of children and observed how aggression played an important role in the development of dominance hierarchies
• What is Ritualistic Aggression?

  Aggressive behaviours that are performed in a repetitive and structured manner e.g. displaying claws and teeth, facial expressions of threat
• What are the six features of fixed action patterns?

  • Stereotyped - Relatively unchanging sequences of behaviour
  • Universal - Same behaviour is found in every individual species
  • Unaffected by Learning - The same for every individual regardless of experience
  • Ballistic - Once the behaviour is triggered it can't be altered before it is complete
  • Single Purpose - Only occurs in a specific situation
  • A Response - To a sign or releaser
• Who conducted research into male sticklebacks and aggression?

  Tinbergen (1951)
• What was the procedure of Tinbergen's research?

  • Another male entering a sticklebacks territory in the mating season initiates a sequence of aggressive behaviours (a FAP)
  • Red on the competing male's underbelly is the stimulus that triggers the IRM that leads to the aggressive FAP
  • Tinbergen presented male sticklebacks with a series of wooden models of different shapes
• What were the findings of Tinbergen's Research?

  • If the model had a red underbelly the stickleback would aggressively display and attack it - but no red meant no aggression
  • He also found that the aggressive FAP did not change from one encounter to another - once triggered it always ran its course to completion without any further stimulus
• Strength of Ethological Explanation:

  Research shows aggression is genetic (Twin studies - Brunner et al) and adaptive (Wilson and Daily)
• Limitation of Ethological Explanation:

  Based on animals so can't be generalised to humans
• Limitation of Ethological Explanation:

  • Behaviours in aggressive FAP vary between individuals / situations
  • Modified by experience