agression - ethological Flashcards
list all the ethological explanations of aggression A01
-adaptive functions of aggression
-ritualistic aggression
-innate releasing mechanisms + fixed action patterns
whats a main function of aggression
adaptation
what’s the adptive function of aggression, why is it beneficial?
-benefical to survival ‘defeated’ animal is rarely killed but forced to establish terrirotory elsewhere.
- means: species spread out over a wide area + discover resources in different place, which reduces competition + possibility of starvation.
-establishes dominance hierarchies.
-male chimpanzees use aggression to climb social hierarchy.
-dominace gives special status.
-happens in humans too.
what does ritual mean
series of behaviour carried in set order
what did Lorenz’s early observation show for ritualistic aggression
Lorenz early observations of fights between animals of the same species was how little actual physical damage was done.
Most aggressive encounters- period of ritualistic signalling + rarely reached point of becoming physical.
Also- Lorenz pointed out that intra-species aggressive confrontations end with ritual appeasement displays. INdicate acceptance of defeat + inhibit aggressive behaviour in victor, prevents damage to loser.
Adaptive because, if every aggressive encounter ended with death this could threaten existence of species.
how is ritualistic aggression adaptive
if every aggressive encounter ended with death this could threaten existence of species.
whats an example of ritualistic aggression in wolves
wolf exposes their neck to the victor
what’s innate releasing mechanism + fixed action patterns
Innate releasing mechanism = built in physiological process or structures.
e.g. network of neutrons in the brain.
Environmental stimulus triggers the IRM which then releases fixed action pattern.
what’s was the key research into IRMs + FAPs
(ethological)
procedure: male sticklebacks r highly territorial during spring mating season, also develop red spot on their underbelly.
if another male enters their territory sequence of highly stereotyped aggressive behaviour occurs. Sign stimulus triggers the innate realsing mechanism - red spot.
Niko tinbergen (1951) presented sticklebacks with wooden models of different shapes.
Findings: regardless of shape if model had red spot stickleback would aggressively display + attack it. if no red spot- no aggression. T also found these aggressive FAPs were unchanging from one encounter to another. once triggered the FAP always ran its course to completion without any further stimulus.
who studied male sticklebacks
tinbergen
study of adaptive functions of aggression in humans
(Pettit)
Pettit et al (1988) studied play groups of young human children.
-observed how aggression played an important role in the development of some children’s dominance over others bring benefits.
e.g. access to resources + getting their own way.
who studied adaptive aggression in humans specifically children
Pettit et al 1988
what’s examples of ritualistic signalling
this is also the examples in Lorenz early observations of animals
-displaying claws
-teeth
-facial expressions of threat
what’s the fixed action pattern list
Stephen Lea (1984) identified 6 features:
1. stereotyped or relatively unchanging sequence of behaviour
2. universal because the same behaviour is found in every individual species
3. unaffected by learning the same for every individual regardless of experience
4. ‘ballistic’ once the behaviour is triggered it follows course + can’t be altered before its completed.
5. single-purpose the behaviour only occurs in specific situation + not any other
6. a response to an identifiable specific sign stimulus
who created the 6 features of the fixed action pattern
Lea
