Aggression: The ethological explanation of aggression Flashcards
What are the three parts to the ethological explanation?
Fixed action patterns and innate releasing mechanisms
Ritualistic aggression
Wolves and doves
What are fixed action patterns?
A series of innate stereotyped behaviours that occur in response to a specific stimulus.
What is a sign stimulus?
A very specific stimulus that triggers the innate releasing mechanisms (IRM) to release the Fixed action patterns (FAP).
What are innate releasing mechanisms?
When triggered by a sign stimulus, the IRM (neural network) communicates with motor control circuits to release the FAP associated with that sign stimulus.
Describe an example of a FAP in aggression?
Red-bellied stickleback fish during mating season.
Belly turns bright red, naturally aggressive towards other red-bellied sticklebacks.
Anything that is red will trigger the FAP, will run until completion. Sign stimulus= sign of another red underbelly.
Describe characteristics of a Fixed action patterns.
Stereotyped - always same behaviour
Universal - same in all members of species
Innate
Ballistic - will run until completion
Sign stimulus required
What is ritualistic aggression and its purpose as an innate mechanism?
Displays of aggression rather than violence (chest beating).
Avoids death of fellow species when resolving issues.
Describe another innate influence on within-species aggressive behaviour.
Instinctive inhibitors that stop members of the same species using biological weapons (claws + teeth in wolves) against each other.
Not present in non-hunting animals (doves). Humans don’t have these, tech development outpaced evolutionary development, so we can kill each other.
AO3: The ethological explanation of aggression
+benefits of ritualistic aggression
+/-hydraulic model in relation to FAPs
-criticism of the instinctive view of aggression
-issue with suggesting members of the same species are inhibited from harming each other
(+AO3) What are the benefits of ritualistic aggression?
Prevents conflict resulting in violence, endangering species.
Anthropogenic evidence in human cultures.
E.g. chest pounding and contests to settle disagreements rather than full-scale fighting.
(+/-AO3) Describe the hydraulic model in relation to FAPs.
Developed by Lorenz.
Each FAP has a reservoir of ‘action-specific energy’ that build up over time. When sign stimulus causes Innate Releasing Mechanism to activate FAP, energy used and reservoir empty.
Behaviour cannot be repeated until reservoir filled again.
(-AO3) What is the issue with suggesting members of the same species are inhibited from harming each other?
Little evidence in actual animal behaviour.
Lions kill cubs of rival mates. Chimpanzees kill rival groups.
More systemic than inhibitory.
Weakens ethological explanation as animal aggression may not be ritualistic but caused by other things.
