Psychology a level - PART 1 aggression

ao1 and ao3

2 neural mechanisms in aggression

limbic system, serotonin

1 hormonal mechanism in aggression

testosterone

what is the limbic system

subcortical structures in the brain (including the hypothalamus and the amygdala) thought to be closely involved in regulating emotional behaviour including aggression

what is serotonin

a neurotransmitter with widespread inhibitory effects throughout the brain, playing a key role in aggressive impulse control

what is testosterone

a hormone from the androgen group produced mainly in the male testes (and in smaller amounts in female ovaries), associated with aggression

study showing role of amygdala in aggression

Gospic et al (2011) found that p’s who reacted aggressively to mild provocation showed a fast and heightened response in the amygdala through fMRI scans

a benzodiazepine drug, which reduces activity of autonomic nervous system, decreased activity of amygdala and reduced aggressive responses by half

role of serotonin and OFC in aggression

low serotonin in the orbital frontal cortex reduces self-control and increases impulsive behaviour, like aggression

study showing role of serotonin in aggression

Virkkunen et al (1994) compared levels of a serotonin metabolite in the cerebrospinal fluid of violent impulsive and violent non-impulsive offenders

found they were significantly lower in impulsive offenders

study showing role of progesterone in aggression

Ziomkeiwicz et al (2021) found a negative correlation between progesterone levels and self-reported aggression

research showing that the limbic system is not the only area of the brain involved in aggression

Coccaro et al (2007) highlights that OFC activity is reduced in psychiatric disorders that feature aggression as the OFC’s impulse-control function is reduced

research support for the impact of SSRIs on aggression

Berman et al (2009) gave p’s either a placebo or paroxetine. p’s then participated in a lab-based game that involved giving and receiving shocks in response to provocation e.g. insults

the paroxetine group consistently gave less and lower shocks

2 animal studies showing role of testosterone in aggression

in male rhesus macaque monkeys there is an increase in both testosterone and aggressive behaviour during mating season

castration of male rats decreased mouse-killing behaviour, injecting female rats with testosterone increased mouse-killing

what is the dual-hormone hypothesis

high testosterone only leads to aggression when cortisol is low as high cortisol blocks testosterone’s influence on aggressive behaviour

key gene linked to aggression

MAOA gene, which regulates serotonin. the low activity variant, MAOA-L, is associated with aggressive behaviour

research on cultural differences in MAOA-L prevalence

Lea and Chambers (2007) found MAOA-L was possessed by 56% of Māori men, compared to 34% of Caucasian men

findings of a twin study on aggression

physical aggression had 50% concordance MZ and 19% DZ

verbal aggression had 28% MZ and 7% DZ

adoption study on aggression

Rhee and Waldman (2002) meta-analysed adoption studies on aggression and antisocial behaviour

found that genetic influence could account for 41% of variations in aggressive behaviour

study on MAOA-environment interaction

Frazzetto et al (2007) found a correlation between aggression and MAOA-L in men, but only in those who had experienced significant trauma before the age of 16

study showing impact of MAOA-H (high level variant)

Mertins et al (2011) found that in a money-distributing game, men with the MAOA-H variant were more co-operative and made fewer aggressive moves than men with MAOA-L

what is the ethological explanation

an explanation of aggression that seeks to understand innate behaviours of animals by studying them in natural environments

what does the ethological explanation suggest is the main function of aggression

it’s adaptive

what is ritualistic aggression

sets of behaviour carried out in a specific order and way, either showing threat or appeasement

what are innate releasing mechanisms (IRM)

inbuilt psychological networks that are triggered by environmental stimuli and release a specific sequence of behaviours

what are fixed action patterns (FAP)

a fixed behavioural sequence, always carried out to completion, caused by IRMs

study on FAPs in stickleback fish

Male sticklebacks display a red spot on their skin during mating season

Tinbergen (1951) presented male sticklebacks with a series of stimuli, such as a model fish with a red spot and a random lump with a red spot

found that regardless of the shape of the stimulus, a red spot always triggered FAP in the male sticklebacks. the FAP was always carried out to completion

study on cultural differences in reactive aggression (undermines ethological explanation)

Nisbett (1993) found reactive homicide to be more common amongst white men in the south of the USA than in the north

concluded this difference was because of a ‘culture of honour’ in the south

therefore reactive aggression is not wholly innate and can be overridden by culture

study showing not all intra-species aggression is ritualistic

Goodall (2010) observed a ‘4-year war’ during which chimps from one community killed all the chimps in another community. the attacks were violent and gory, even when the victims offered ritualistic appeasement symbols

is the original idea of FAPs (as proposed by Lorenz) outdated

yes, psychologists now believe they vary between individuals and are influenced by experience

3 evolutionary explanations for male-on-female aggression

sexual jealousy, mate retention strategies, cuckoldry

study on sexual jealousy

Daly and Wilson (1988) found males would use direct violence and guarding strategies to deter infidelity

study on mate retention strategies

Buss and Shackleford (1997) studied 214 married couples and found males used debasement and threats to try and prevent their partner from leaving them

study on cuckoldry

Camilleri (2004) found males are more likely to be sexually coercive when perceived risk of cuckoldry is high

evolutionary explanation for murder

an adaptive response to a lack of resources, low status, or war

study on murder as a response to lack of resources

Wilson and Daly (1985) found that 43% of male victims and 41% male perpetrators in a Detroit prison were unemployed. 73% of victims and 69% of perpetrators were unmarried

study on murder as a response to a low status

Wilson and Daly (1988) found a correlation between income-inequality and murder rates

study on link between war and evolutionary theory

Lehmann and Feldman (2008) studied the highly aggressive Yanomamo tribe and found that aggressive genes were being passed down, increasing the traits of belligerence and bravery within the culture

example showing aggression to be culturally influenced

the !Kung San people of the Kalahari are peaceful and have a negative attitude to aggression where aggressive individuals are shunned and have a diminished status

what is the frustration-aggression hypothesis

a social psychological theory of aggression that argues aggression is always the outcome when goals are blocked

what was the premise of the original F-A hypothesis

frustration always leads to aggression and aggression is always caused by frustration

why might aggression not be directed towards the frustrater in the F-A hypothesis

frustrater may be abstract, risky to attack, or unavailable

how does the F-A hypothesis view an aggressive behaviour

as a catharsis - a psychodynamic explanation

how has the F-A hypothesis been modified

to recognise the weapon effect, suggesting frustration primes people for aggression but cues lead it to be carried out

study on the weapon effect

Berkowitz and LePage (1967) has p’s given electric shocks by a confederate first. they could then give shocks back, with some p’s having a gun present in the room while others didn’t

p’s with a gun in the room gave an average of 6 shocks, while those without gave an average of 4.5

study showing effect of frustration on aggression

Geen (1968) had male university students solve a jigsaw puzzle in 1 of 3 conditions: impossible puzzle, confederate causing them to run out of time, confederate insulting them for failing. all p’s could later give the confederate electric shocks

the insulted p’s gave the strongest shocks, then the second condition, then the first. all 3 frustrated groups gave stronger shocks than a control group

study on displaced aggression (supports F-A hypothesis)

Marcus-Newhall et al (2000) meta-analysed 49 studies of displaced aggression

found frustrated p’s were significantly more likely to attack an innocent 3rd party than un-frustrated p’s when the frustrater was not available

concluded displaced aggression is a reliable phenomenon

study undermining the idea that aggression is cathartic

Bushman (2002) found p’s who vented their anger by hitting a punchbag became more aggressive rather than less

concluded “the better people feel after venting, the more aggressive they are”

how does SLT explain aggression

it is a social psychological explanation that suggests aggressive behaviour is learnt through observing and imitating role models, as well as direct and indirect reinforcement

what is self-efficacy (a part of SLT)

the extent to which actions are believed to lead to a desired goal

e.g. a child’s aggression increases when their confident sense of self-efficacy that aggression leads to rewards is reinforced

research support SLT in explaining aggression (not bobo doll study)

Poulin and Boivin (2000) found that aggressive boys aged 9-12 form friendships with other aggressive boys because they mutually reinforce each others behaviour through modelling

HOWEVER, no link in terms of reactive aggression