Ethological explanations of aggression Flashcards
How is aggression adaptive
Beneficial to survival as defeated animal has to find other territory
=species have to spread out/find resources in new place
= - competition pressure/possibility of starvation
-Also to establish dominance hierarchies (e.g male chimpanzees)
Study of humans establishing dominance
Pettit et al (1988) Studied young children and observed how aggression made dominance hierarchies
=Adaptive as dominance brings benefits e.g access to resources
Lorenz theory of ritualistic aggression
Intra-species fights ended in little damage
-Aggression was prolonged ritualistic signalling (e.g flashing teeth)
-Ended in ritual appeasement displays
What are ritual appeasement displays
Submission- indicate acceptance of defeat/prevent further aggressive behaviour
Example of ritual appeasement displays
Wolf exposes its neck to victor
Why does intra-species aggression result in little damage
If every aggressive encounter ended with death it could threaten the existence of the species
What is an innate releasing mechanism (IRM)
Inbuilt physiological process or structure
What is an Fixed action pattern (FAP)
Specific sequence of behaviour released when IRM triggered by environmental stimulus
What are the six main features of FAPS according to Stephen Lea
Stereotyped
Universal
Unaffected fed by learning
Ballistic
Single-purpose
Response
What does FAPS being ballistic mean
One behaviour triggered it follows inevitable course and can’t alter
What does FAPS being stereotyped mean
Relatively unchanging
What does FAPS being single purpose mean
Only occurs in a specific situation
Tinbergen’s research into FAPS procedure
Presented sticklebacks with a series of wooden models of different shapes
What is the sign stimulus for male sticklebacks in mating season
Red spot on underbelly= aggressive FAP
Findings of Tinbergen’s research
-Regardless of shape males would attack model with red dot
-No red dot= no attack
-FAP always ran it’s course without further stimulus