Ethological and evolutionary Flashcards
What is an ethological explanation?
An explanation that seeks to understand the inmate behaviour of animals and humans by studying them in their natural environment.
What are the 2 reasons for aggression being an adaptive function?
- Aggression is beneficial for survival.
- Aggression is used to establish dominance hierarchies.
How is aggression beneficial for survival?
- ‘Defeated’ animals are rarely killed, but rather forced to establish territory elsewhere.
- Members of species are spread out over a wider area and have to discover resources in different places.
- This reduced competition pressure and the possibility of starvation.
How is aggression used to establish dominance hierarchies?
- Male chimpanzees use aggression to climb their troop\s social hierarchy.
- Their dominance gives them special status.
Who conducted research into aggression being an adaptive function?
Pettit.
What did Pettit find?
- Studied play groups of young human children and observed how aggression played an important role in the development of some children’s dominance over others.
- This would be adaptive because dominance over others brings rewards, e.g. power to get your own way.
Who conducted research into ritualistic aggression?
Lorenz
What did Lorenz find?
- Observed fights between animals of the same species and saw that little physical damage ever occurred.
What did more aggressive encounters consist of?
A period of ritualistic signalling (e.g. displaying of claws and teeth) and rarely reached the point of becoming physical.
What did Lorenz observe at the end of confrontations?
Confrontations end with ritual appeasement displays to indicate acceptance of defeat and inhibit aggressive behaviour in the victor.
E.G. at the end of confrontation a wolf will expose its neck, leaving itself vulnerable to a single bite to its jugular vein.
How is ritualistic aggression adaptive?
Adaptive as if every aggressive encounter ended with death, this could threaten the existence of the species.
What is an innate releasing mechanism?
A biological process/structure which is activated by an external stimulus that in turn triggers a fixed action pattern.
What is a fixed action pattern?
A sequence of stereotyped pre-programmed behaviours triggered by an innate releasing mechanism.
Who suggested that FAPs have 6 main features?
Lea
What are the 6 main features of FAPs?
- Stereotyped
- Universal
- Unaffected by learning
- ‘Ballistic’
- Single-purpose
- A response to an identifiable specific sign stimulus
Who conducted research into IRM and FAPs?
Tinbergen
What was the procedure of Tinbergen’s study?
- Male sticklebacks are highly territorial and during mating season develop a red spot on their underbelly.
- If another male enters their territory, a sequence of highly stereotyped aggressive behaviours is initiated (a FAP).
- The sign stimulus that triggers the IRM is the sight of the red spot.
- Tinbergen presented sticklebacks with a series of wooden model of different shapes.
What were the findings of Tinbergen’s study?
- Regardless of shape, if the model had a red spot the stickleback would aggressively display and even attack it.
- Tinbergen also found that these aggressive FAPs were unchanging from one encounter to another.
State a positive of the ethological explanation.
Supporting research:
- Brunner (MAOA gene)
- Limbic system
- Ethological explanation argues that aggression is genetically determined, its validity is supported by evidence that demonstrates the genetic and physiological basis of aggression.
State 3 negatives of the ethological explanation.
Cultural differences:
- Nisbett’s north-south divide in the US for homicide rates.
- ‘Culture of honour’.
Evidence against ritualistic aggression:
- Goodall - Tanzania chimpanzees.
- ‘Four year war’ - co-ordinated and premeditated attacks that continued even when the victims offered signs of appeasement and defencelessness. These signs didn’t inhibit the aggressive behaviour.
Unjustified generalisation to humans.
What does the evolutionary explanation for sexual jealousy suggest:?
- Unlike women, men can never be totally sure about whether or not they have truly fathered a child (paternity uncertainty).
- Sexual jealousy is greater in males because it is an evolved psychological mechanism to prevent cuckoldry (raising another mans child).
- Having to raise offspring that do not share the male’s genes is a waster of his resources and investment.
- It contributes to the survival of a rival’s genes and leaves the ‘father’ with fewer resources to invest in his own future offspring.
Who identified several mate retention strategies?
Wilson and Daly
What are the 2 mate retention strategies?
Direct guarding - involves male vigilance over a partners behaviour (e.g. keeping tabs on their whereabouts).
Negative inducement - such as issuing threats of dire consequences for infidelity (e.g. ‘I’ll kill myself if you leave me’).
What did Wilson find in her research into mate retention strategies?
- Found that women who reported mate retention strategies in their partners were twice as likely to have suffered physical violence at the hands of their partner.
- 73% needing medical attention.
- 53% said they feared for their lives.
Who conducted a study into intimate partner violence?
Shackelford
What was the procedure of Shackelford’s study?
- Studied men and women in 107 married couples who completed different questionnaires.
- Men - completed the mate retention inventory, which assessed mate retention behaviours.
- Women - completed the spouse influence report, which measured the extent of their partner’s violence in their relationship.
What did Shackelford find in his study?
- Strong positive correlation between men’s reports of their mate retention behaviours and women’s reports of their partner’s physical violence.
- So men who used guarding or negative inducement were more likely to use physical violence against their partners.
Who argues that the characteristics associated with bullying behaviour are attractive to the opposite sex?
Volk
What characteristics do males show when they bully?
Dominance
Acquisition of resources
Strength
Why would bullying in males be evolutionary?
The characteristics are an ideal combination of access to more females.
Behaviour would be naturally selected because these males would have greater reproductive success.
Why would bullying in females be evolutionary?
Bullying often takes place within a relationship and is a method of controlling a partner and securing a partner’s fidelity, which means they can continue to provide resources for future offspring.
Naturally selected behaviour due to enhanced reproductive success.
State 3 positives of the evolutionary explanation.
Research support for aggression and sexual jealousy:
- Shackelford et al.
- Indicates clear link between the greater risk of infidelity, cuckoldry and aggression.
Evolutionary explanations account for genetic differences:
- Campbell: females with offspring are less likely to be aggressive because the behaviour may but her and her childs survival at risk.
- Prefer verbal aggression.
Real-life application:
- Volk et al.
- Anti-bullying interventions
