ethological explanations

• Innate releasing mechanism (RM)

  A built-in physiological process or structure, for instance a network of neurons (a circuit) in the brain. triggers FAP
• Fixed action pattern (FAP)


  A specific sequence of behaviours triggered by an innate releasing mechanism
• Features of fixed action patterns

  • Stereotyped or relatively unchanging sequences of behaviours
  • Universal, because the same behaviour is found in every individual of a species
  • Unaffected by learning, the same for every individual regardless of experience
  • Ballistic, once the behaviour is triggered it follows an inevitable course and cannot be altered before it is completed
  • Single-purpose, the behaviour only occurs in a specific situation and not in any other
  • A response to an identifiable specific sign stimulus (or, if it involves communication between members of the same species, it is known as a releaser)
• adaptive functions 


  agg main purpose is to be adaptive and beneficial to survival. defeated animal doesn't die but moves territory so decrease competition and increase resources. survival advantage. also establish dominance in a hierarchy to gain a special status

  petti: observed children play groups, more agg more dominance
• ritualistic aggression


  series of behaviour carried out set order. Lorenz found little physical agg but all showed ritualistic signalling eg showing teeth. and would end with appeasement displays eg wolf exposing neck to show defeat, in intra-specie confrontations. adaptive as it doesn't end in death lead to decrease in population
• key study: FAPs and IRMs 


  male sticklebacks are highly territorial during mating seasonsand develop a red spot under belly. if another male enters a FAPs of steryotyped behaviour occurs. Tinbergen tested if shape or present of red spot and found if red spot was present would trigger a FAP no red spot no aggression. also same behaviour each time.
• a03: supporting research.


  a innate basis was created by Brunner showing low activity of the MAOA gene is associated with agg in humans. also activity in the lymbic system is associated. explanation suggests agg is heritable and genetically determined. increases validity as it shows support for genetic basis to agg
• a03: cultural differences 


  more agg in some cultures compared to others Nisbett found north-south divide in US in homicide rates. more killings more common in white males in southern parts. only true for reactive agg. he concluded caused by culture honour. and how to respond to agg was learnt in social norms. lab study white southern males more aggressive after being insulted then northern. limitation as agg isnt innate
• a03: evidence against ritualistic agg

  agg has evolved into a self-limiting and physically harmless has been challenged. by Goodall in chimpanzees at a national park. there was a four year war were one community of male chips would systematically slaughter all members of another group. was co-ordinated and premeditated as the attack lasted up to 20 mins and attack continued despite showing appeasement signals. limitation as didnt stop the attack like the explanation predicted