ethological explanations

• Ethological explanations (Hydraulic model):

  • aggressive energy builds up
  • puts pressure on IRM
  • competing animal (sign stimulus) triggers IRM
  • IRM cant hold back the energy
  • aggression (FAP)
  • if energy is too high, aggression with no sign of stimulus present
• Ethological explanations (ritualistic aggression):

  Threat display:

  • help asses relative strength before escalating the conflict
  • makes dangerous physical aggression less likely
  • makes opponent back down
  • last step before submission or leaving

  Threat display and humans:

  • Fox (1978)
  • ritualized fighting of Gaelic tory island
  • threat displays instead of actual aggression
• Ethological explanations (Fixed action patterns):

  • Lea (1984)
  • stereotypes, always occur in same way
  • universal, same in all conspecifics
  • ballistic, FAP cannot be stopped when triggered specifically
  • independent of individual experience
• Ethological explanations (Wolves and doves):

  • lorenz
  • instinctive inhibitions to not use on own species
  • wolves: fight ends when losing animal exposes its neck submissively, teeth as hunting weapons
  • doves: can fly away, no natural weapons

  Humans:

  • more like dove
  • no powerful natural weapons
  • developed strong instinctive inhibitions against killing each other
  • use artificial weapons through technology
• Ethological explanation:

  • all members of same species have stereotyped behaviors
  • occur in specific conditions
  • innate (not learnt)
• Ethological explanations (innate releaser mechanism):

  • triggered by sign stimulus (e.g. competing animal)
  • receives input from sensory recognition circuits
  • releases FAP associate with the sign

  Tinbergen's Sticklebacks:

  • produce FAPs when another male enters territory
  • sign stimulus is distinctive red underbelly
  • arent attacked if this is covered