Ethological Explainations

• Key ethologists - Lorenz & Tinbergen

  Tinbergen

  ↳ all members of the same species have fixed action patterns

  ↳ fixed action patterns are released by an innate neural circuit called the innate releasing mechanism
• humans

  ↳ pettit et al

  ↳ young children used aggression to assert dominance

  ↳ dominance brings other benefits like power and access to resources

  ↳ forces other animals to spread other the territory

  → adaptive

       ↳ for individuals and for the species as a whole
• Ethological Explanations

  ↳ study of behaviour patterns in NHA's

  ↳ can apply findings to humans

  ↳ potential to be aggressive is innate but is triggered by a sign stimulus in the enviro.
• Ritualistic Aggression

  ↳ intention is not kill

  ↳ rituals - behaviours in a set order

  ↳ Lorenz observed fights in animals - little damage was done

  ↳ Lorenz - intraspecies aggression ends with appeasement displays

       ↳ acceptance of defeat

       ↳ adaptive - death could threaten the species
• Innate Releasing Mechanisms & Fixed Action Patterns

  ↳ amygdala in humans

  ↳ built in physiological process
• Fixed Action Patterns

  ↳ specific sequence of behaviours
• Stephen Lea - 6 main features

  → stereotyped

  ↳ unchanging sequence

  → universal

  ↳ same behaviour in every individual in the species

  → unaffected by learning

  → ballistic

  ↳ once triggered the benaviour must be carried out

  → single purpose

  ↳ only occurs in specific situations

  → response to an identifiable specific sign stimulus
• Build up of action specific energy

  (e.g aggression in stickle-back fish)

  ↓

  Sign Stimulus in the environment

  (male stickle-backs develop red belly during mating)

  ↳ trigger for attack

  ↓

  Innate releasing mechanism

  (innate

  ↳ part of the brain

  ↳ humans = amygdala )

  ↓

  fixed action pattern

  (sequence of aggressive behaviours)
• Procedure - Tinbergen

  ↳ male sticklebacks are highly territorial

  ↳ develop red spot during mating season

  ↳ When another mare enters the territory

        ↳ FAP is triggered

        ↳ sequence of aggressive behaviours

  ↳ sign stimulus triggers the innate releasing mechanism of sighting the red spot

  → Tinbergen presented Sticklebacks to wooden models of different shapes
• Findings

  → regardless of shape, if there was a red spot it would be attacked

  →no red spot = no aggression

  → aggressive FAPs were unchanging

  ↳ Always ran their course 
• P - Tinbergen

  male stickle back fish

  E - red underbelly - sign stimulus

  ↳ leads to FAP by any threatened stickleback

  - a model without a red underbelly would not be attacked

  ↳ whether they looked like a stickleback or not

  C-evidence to support sign stimulus & FAP

  ↳ apply to all members of NHA species
• P - Gardner et al

  - Fox

  E - Gardner

  ↳ Dani people of new guinea have highly ritualized patterns of inter-group hostility

  - Fox

  ↳ ritualised fighting by Gaelic speaking males in Tory Island

  C - Lorenz, aggression by conspecifics is usually

  ritualised

  - intention to establish dominance not to inflict harm
• P - criticism by Lehrman

  E - aggressive behaviour of NHAs is learned from environment

  C - undermines that aggressive behaviours are entirely innate & unlearned
• P - extent to which they can be generalised to human,

  E - Lorenz & Tinbergen studied NHAs

  ↳ extrapolated their findings to humans

  ↳ Tinbergen suggested that humans may be only species without ritualized aggression

  → fox

  ↳ human aggression involves warfare between societies rather than 2 individuals 

  - many examples do not resemble ritualised aggression

  ↳ Lorenz - holocaust

  C - undermines theory

  - limits extent to which concepts based on NHAs can be applied to human aggression