evolutionary influences on aggression Flashcards
(20 cards)
what does the ethological explanation believe?
that aggression is instinctive in all species and is adaptive
what are the adaptive functions of aggression?
Defeated animals rarely killed but instead spread out over a wider area reducing competition for resources.
Victorious animals have the resources and establish dominance in a hierarchy.
what is ritualistic aggression?
most aggressive encounters between animals involve a lot of signalling and display but rarely life-threatening violence or damage.
what is an innate releasing mechanism (irm)?
A built-in physiological mechanism that is triggered by an environmental stimulus (e.g. an aggressive facial expression) and which in turn sets off a FAP.
what is a fixed action potential (fap)?
A specific sequence of behaviours that is released by an IRM, FAPs are unchanging and universal in a species, unaffected by learning, always play out to completion, and occur only in a specific situation.
what is lorenz’s hydraulic model?
believes aggression builds up in an individual (IRM) like a tank filling with liquid. when the aggression is too much this spills over until an event occurs to release the aggression (FAP)
what are the 6 main features of an FAP?
stereotyped
universal
unaffected by learning
ballistic
single purpose
responsive
outline tinbergen’s research
undertook an experiment with male sticklebacks. This species of fish is very territorial and aggressive. In the mating season they develop a red spot on their underside. Tinbergen observed that at this time male sticklebacks will attack another male stickleback that enters their territory. He theorised that the red spot on their underside was acting as an innate releasing mechanism and when one stickleback observed another stickleback with this red spot they would initiate the aggressive attack behaviour which is an example of a fixed action pattern. To test this out he presented male sticklebacks with a wooden model; if the wooden model had a red spot, then the male stickleback would attack. However, without the red spot the male stickleback would not react, and there was no aggression displayed.
what are the evolutionary functions of aggression?
ensure strongest and fittest are selected
ensure survival of young
help distribute a species in a balanced way
what does the evolutionary perspective suggest about aggression?
suggests that aggression is the result of sexual competition, so males can pass on their reproductive success
strengths of the ethological explanation of aggression
research to support related to genetics and evolution. twin and adoption studies suggest a genetic link to aggression, which supports the ethological argument that aggression is innate
universal argument - means it has high cross cultural validity and can easily be generalised
limitations of the ethological explanation
Lorenz original view of FAPs is outdated - whilst he said they were innate and didn’t change it has since been discovered they are greatly influenced by our environment and experiences
aggression against members of the same species isn’t just ritualistic e.g chimps killing each other. challenges the ethological view that same species aggression has become relatively harmless
what are two areas that fuel aggression in humans and threaten our survival / fitness?
Infidelity and jealousy
what is the evolutionary explanation of sexual jealousy?
Sexual jealousy is greater in males because it is an evolved psychological mechanism to prevent cuckoldry.
This ensures the male does not waste his resources raising another man’s child.
what are mate retention strategies?
Male monitors his partner’s behaviour (direct guarding) and threatens them (negative inducements) to prevent them straying. These strategies are linked with aggressive behaviours.
what is the evolutionary explanation of bullying?
Bullying is adaptive because the characteristics associated with it in males (dominance, resources, strength) are attractive to females.
This gives the bully more opportunities for reproduction.
what is the evolutionary explanation of violence against the partner?
Wilson et al.: women who said their partners used mate retention were likely to have experienced physical aggression.
outline kniffin and wanskink’s research
Kniffin and Wansink (2012) wanted to know if the prospect of your partner’s ex inviting your partner out to lunch might be enough to trigger sexual jealousy.
They recruited 79 university students (52 men and 27 women). They presented the participants with six brief scenarios involving their current romantic partner being contacted by their ex-partner and spending time with them. The six scenarios all began, ‘Recently, your girlfriend/boyfriend was contacted by her/his ex-girlfriend/boyfriend and she/he spent approximately one hour …’
They continued:
… corresponding via e-mail.
… talking on the phone.
… meeting for late-morning coffee.
… meeting for lunch.
… meeting for late-afternoon coffee.
… meeting for dinner.
The participants had to imagine how they would react and rate how jealous they would be in each scenario on a five-point scale from ‘Not at all jealous’ to ‘Very jealous’.
The researchers found that the meal scenarios produced higher jealousy ratings than the coffee scenarios. Talking on the phone produced more jealousy than e-mail. Perhaps surprisingly, there were no differences between men and women in the degree of reported jealousy for any of the scenarios.
strengths of the evolutionary explanation
can account for gender differences - outlines why different behaviours occur in males and females. not adaptive for a new mum to be aggressive - risks her and child
offers practical useful applications such as reducing bullying - usually done by identifying bullies deficiencies
limitations of the evolutionary explanation
substantial cultural differences in aggression - aggressive behaviour is discouraged from early childhood in some areas of africa
not all men show aggression when threatened or jealous - may be issues establishing cause and effect
