Ethological and Evolutionary Explanations of Aggression Flashcards
(16 cards)
What is ethology?
- The study of naturally occurring animal behaviour, which can include human behaviour,
- Ethologists usually look at a particular type of behaviour across species.
How did Lorenz define aggression?
- Proposed a theory of aggression based on animal behaviour, which he applied to humans too,
- He defined aggression as fighting instinct directed at members of your own species.
What was Lorenz’s theory of aggression?
- Argued that aggression has evolved as an adaptive response - an individual will be more likely to pass on their genes if they are able to gain the upper hand in competition for food, mates, and territory,
- He describes aggression as an innate tendency that is triggered by environmental stimuli.
What is the process of aggression in Lorenz’s theory?
- The urge to engage in aggressive behaviour builds up continuously over time - the more time that has passed since the last release of aggression, the more an animal feels internal pressure to be aggressive,
- Eventually a stimulus will trigger aggression,
- As the internal pressure to release the aggression builds upm the strength of stimulus needed to trigger this decreases. If the pressure is very high then aggression might be triggered spontaneously,
- The stimulus triggers an innate releasing mechanism - this is a proposed ‘innate pathway’ in the brain which sets off a fixed action pattern,
- A fixed action pattern is an instinctive behaviour which is identical across a species. For example, babies instictively grab things they are offered and hold on tightly.
Where has Lorenz’s theory of aggression been observed?
Observed in red-bellied sticklebacks,
1. During breeding season the male sticklebacks develop bright red bellies. In males, seeing the bright red of another male’s belly stimulates an innate releasing mechanism, which triggers specific fighting behaviour, the fixed action pattern, directed towards the rival,
2. Tinbergen (1947) found that this response was triggered more by unrealistic models with red undersides, such as diamond shapes with no features, than by real sticklebacks with no red belly,
3. This supports the suggestion that the behaviour is instinctive, and set off by a specific trigger.
What does Lorenz posit on the ritualism of aggrssion release?
- A behaviour won’t be passed on through genes if it gets the animal killed before it produces offspring. If animals were routinely killed during everyday power struggles or mating contests, it is likely the species would become extinct. So, there are ritual behaviours in place to stop confrontations being fatal,
- For example, wolves end a fight by the loser exposing his jugular vein as a sign of submission. This puts the winner in prime position to kill their rival, but in fact the winner takes no further action,
- Lorenz claimed that sport was an example of harmless ritualised aggression release in humans, and argued that sport was an important method for reducing aggression in society.
Strengths of the ethological explanation of Aggression?
- Aggression does occur as a fixed action pattern in some animals,
- This theory could explain why humans kill each other relatively often - without weapons human fighting isn’t usually lethal, so we haven’t evolved to back down. Now that we have access to weapons, fights are more likely to kill.
How does evolutionary psychology explain aggression?
- Explains aggression as a strategy that has evolved as an adaptive response to problems,
- This argument is that using aggression helped individuals to survive and reproduce in the past - so aggression is a trait that modern humans have inherited.
Weaknesses of the ethological explanation of aggression?
- Theory doesn’t explain aggression which isn’t an immediate response to an environmental stimulus, e.g. premeditated murder,
- Arms et al. (1979) found that watching aggressive sport increased aggression in participants, rather than dispersing it.
What functions do evolutionary psychologists posit to aggression?
1.To gain status or dominance in a group,
2. To gain resources from others, e.g. territory or mates,
3. In defence,
4. To deter infidelity in long-term mates.
What did Wilson and Daly (1985) find?
- Studied murders in Detroit and found that the majority of perpetrators and victims were young men,
- 29 of the cases they looked at were murders that had resulted from ‘escalated showing off disputes’, and only one of these murders resulted from a dispute between women.
What do evolutionary psychologists argue of aggression in relation to men?
- Argue that men, and young men in particular, are more aggressive because they faced the most competition for mates in the past,
- The main limit on men’s reproduction was access to fertile mates, so competing successfully for mates was important.
Buss et al. (1992), method?
- This was a cross-cultural questionnaire study,
- Participants were presented with the hypothetical scenario that someone they were in a serious, committed romantic relationship with had become interested in someone else,
- They were asked what would distress them more - imagining their partner forming a deep emotional attachment to that other person, or enjoying passionate sexual intercourse with the person.
Buss et al. (1992), findings?
- Across all studies, more men than women reported sexual infidelity to be most upsetting,
- On average, 51% of the men versus 22% of the women chose this to be more distressing than emotional infidelity.
Buss et al. (1992), conclusion?
- Men’s jealousy is innately triggered by the threat of uncertainty over the paternity of children produced within the relationship,
- However, women are more threatened by emotional investment as it could mean being left behind for another woman, and so reducing the resources available to her children.
Buss et al. (1992), evaluation?
- The fact that the evidence was consistent across different cultures suggests that these different response are innate rather than learnt.
- However, the fact that the questionnaires were based around a hypothetical situation, and the response available to the participants were multiple choice, means that the validity of the results is questionable; they may not accurately reflect what participants would actually do if they found themselves in that situation.
