ETHOLOGICAL EXPLANATION

• What is the ethological explanation?

  Seeks to understand the innate behaviour of animals by studying them in their natural environment
• what are innate releasing mechanisms?

  biological structure or process which is activated by an external stimulus that in turn triggers a fixed action pattern
• what are fixed action patterns?

  a sequence of stereotyped pre-programmed behaviours triggered by an innate releasing mechanism
• why is aggression beneficial to survival?

  reduced competition because a defeated animal is forced into territory elsewhere

  establishes dominance hierarchies
• what is ritualistic aggression?

  series of behaviours carried out in a set order for example threat displays and appeasement displays which are used to resolve disputes between animals so that they can reduce the physical damage that conflict brings
• what are threat displays?

  growling, showing teeth
• what are appeasement displays?

  indicates acceptance of defeat and inhibits aggression in the winner, preventing damage to loser
• Key study : Tinbergen

  Male Sticklebacks and aggression

  Procedure:

  presented male sticklebacks with a series of wooden models of different shapes, another male entering their territory in the mating season initiates a sequence of behaviours. Red on the underbelly is the stimulus that triggers the IRM in turn leading to the aggressive FAP
• Tinbergen findings

  if the model had a red underside the stickleback would aggressively display and attack it, no red meant no aggression. Also found the aggressive FAP didn’t change from one encounter to another, once triggered it always ran its course to completion without any further stimulus
• what are the key features of fixed action patterns?

  Stereotypes, universal, unaffected by learning, ballistic, single purpose and a response
• Stereotyped - relatively unchanging sequences of behaviour
• universal - found in every individual of the species
• Unaffected by learning - same for every individual regardless of experience
• ballistic - once the behaviour is triggered it cannot be altered before it is completed
• single purpose - only occurs in a specific situation
• a response - to a sign or releaser
• Evaluation point 1

  STRENGTH supporting research

  Brunner et al shows low activity variant of the MAOA gene is closely associated with aggressive behaviour suggesting an innate biological basis.

  Activity In the limbic system triggers aggressive behaviour - evidence for IRM
• Evaluation point 2

  LIMITATION cultural differences

  if it was innate then we would see the same behaviour in all humans. Nisbett found that killings amongst white males was much more common in southern US states then northern states. Only true for reactive aggression triggered by arguments, concluded difference was due to ‘culture of honour’ in the south that wasn’t presenting the north.
• Evaluation point 3

  LIMITATION - evidence against ritualistic agression

  Goodall observed that male chimps from one community systematically slaughter the members of another group in a coordinated and premeditated fashion. On occasions, victims were held down in a sustained attack despite showing appeasement and defencelessness. Challenge view of ethological explanation
• Evaluation point 4

  LIMITATION unjustified generalisations to human aggression

  Lorenz didnt study higher mammals and Tinbergen did not study the extreme destructive violence that is a feature of human aggression. Both made generalisations from animals to humans, including warfare. Lorenz generalised to entire countries. Lack validity, need to be cautious about such generalisations especially for complex behaviour