3.1.3 (part 2) - brain structure as an explanation of aggression

Question 1

what is aggression?

Answer 1

behaviour which is intended to physically or psychologically hurt others (so even if it doesn’t succeed it still counts as aggression)

Question 2

what is reactive-hostile aggression?

Answer 2

when an individual is in a heightened emotional state and has a goal to hurt the target

Question 3

what is controlled-instrumental aggression?

Answer 3

when an individual is pursuing another goal but hurts someone in the process of doing this

Question 4

how is the midbrain involved in aggression?

Answer 4

contains the periaqueductal grey matter (PAG), which plays a role in modulation of pain and defensive behaviour
it coordinates and integrates behavioural responses to perceived internal and external stressors eg. heat and pain

Question 5

role of midbrain - Lonstein and Stern (1998)?

Answer 5

showed that lesions (damage that causes area to die) to PAG in rats which have recently given birth show increased aggression when confronted with a potential threat (unfamiliar male rat)

Question 6

how is the amygdala involved in aggression?

Answer 6

centre for emotions (particularly anger and fear), emotional behaviour and motivation
gives us instinctive reactions to the environment, including aggression - allows us to perceive and respond (though aggression) to threats
pre-frontal cortex is connected to amygdala and this connection may lead to expression of aggression
helps us recognise emotion in others

Question 7

how is the hypothalamus involved in aggression?

Answer 7

it maintains homeostasis by regulating hormones, so it links to aggression in males because it produces testosterone
electrically stimulating the hypothalamus in cats can cause them to pounce - influences attack behaviour

Question 8

how is the pre-frontal cortex involved in aggression?

Answer 8

it doesn’t produce emotions or the resulting behaviours but is important in regulating them
has connections to amygdala and hypothalamus
allows us to make choices about our behaviour by thinking through the options ie. can decide whether or not we act on aggressive impulses (impulse control)
explains why damage to this area can cause problems with anger management and impulsive behaviour

Question 9

how is the limbic system involved in aggression?

Answer 9

it is where the amygdalae and hypothalamus is found, so could be where aggressive impulses originate

Question 10

how do different brain areas interact to bring about aggressive behaviour?

Answer 10

1. we receive info from the environment via the senses
2. amygdala interprets info as a threat (fear) or provocation (anger)
3. hippocampus influences our interpretation based on memories from previous experiences and pre-frontal cortex exercises inhibitory control
4. hypothalamus activates aggressive behaviour

Question 11

supporting evidence - Raine et al. (1997)?

Answer 11

used PET scans to compare 41 murderers (who pleaded not guilty by reason of insanity) with control group of non-offenders, found that murderers had lower levels of activity in pre-frontal cortex and differences in functioning of limbic system

Question 12

supporting evidence - Raine et al. (1998)?

Answer 12

used PET scans to compare offenders in different types of violent crime, found lower levels of activity in pre-frontal cortices of emotional-impulsive offenders compared to planned-predatory offenders and control group

Question 13

supporting evidence - Swantze et al. (2012)?

Answer 13

correlation study comparing volume of pp’s amygdalae with self-reported levels of aggression, found a significant strong negative correlation (individual differences in aggression linked to individual differences in brain structure)

Question 14

supporting evidence - Gorka et al. (2013)?

Answer 14

used fMRI scans to compare how the brains of pps who had and hadn’t consumed alcohol reacted to pictures of angry and fearful faces, found that alcohol reduced the reactivity of the amygdalae and orbitofrontal cortex (alcohol changed perception of threat and fear)

Question 15

strengths of brain structure as an explanation of aggression - supporting evidence?

Answer 15

there are lots of studies (including Phineas Gage) which support the idea that abnormal brain structure or function can cause higher levels of aggression

Question 16

strengths of brain structure as an explanation of aggression - consistency with genetic explanation?

Answer 16

genetic blueprint builds brain structures, so people with a genetic blueprint for aggression will also have brain structures which predispose them to aggressive behaviour

Question 17

weaknesses of brain structure as an explanation of aggression - use of animals in research?

Answer 17

lots of lab research into the topic has used animals
there are problems with generalisability across species
lots of research has been done by damaging precise brain areas in cats an d rodents, but human brains are much more complex than those of small rodents
ethical issues as some say it is immoral but others say it isn’t worse than using them as pets or food - studies with animals now need cost-benefit analysis (balances suffering of animal against quality of research and medical benefit of knowledge)

Question 18

weaknesses of brain structure as an explanation of aggression - supporting evidence?

Answer 18

could say that supporting evidence like Phineas Gage is one study so not representative of other humans

Question 19

weaknesses of brain structure as an explanation of aggression - reductionist?

Answer 19

theory could be seen as this because it reduces the production of aggressive behaviour down to the function of the nervous system, but ignores other possible causes like social learning (supported by fact that some cultures show higher average aggression which is likely to be due to social learning)

Question 20

weaknesses of brain structure as an explanation of aggression - biological determinism?

Answer 20

some people may use theory to argue that your behaviour is determined by your biological makeup so individuals have no free will over how they behave - cold be harmful as people may use as defence or excuse for violent behaviour (people say they aren’t responsible), and it may limit their willingness to engage in treatments like anger-management therapy if they think their behaviour can’t be changed