aggression Flashcards
neural influences
biological explanation of aggression
the limbic system:
amygdala = responsible for attaching emotional significance to sensory info + decides when we need to be aggressive
-> more activity here = more aggression
– it takes info from thalamus & interprets if there’s a threat => aggressive (threat) or fear (flight)
hypothalamus = controls FoF response + produces aggressive behaviour
- if the event = dangerous -> amygdala sends nerve impulses to the hypothalamus
hippocampus: -> involved w forming long-term memories
- compares conditions of current threat w similar past exps
– as it sends stored info (from memory) to amygdala
- impaired hippocampal function prevents the nervous system from putting things into relevant + meaningful context
prefrontal cortex = crucial for regulating social behaviour + aggressive responses
– if damages -> less regulation of amygdala => high levels of aggression
- sends electrical signals to inhibit neurons in the amygdala
- prevents agg when appropriate
- when the brain = working efficiently -> upper + mid brain = communicating effectively
- info = comes in -> processed logically
– sometimes too much info = coming in from upper brain to process => disconnects
– gets angry => no longer access provided by upper brain
hormonal influences
biological explanation of aggression
serotonin: {decs aggression}
- serotonin deficiency hypothesis
– S = released @ synapses & inhibits the firing of the neurons (hence less activity in the amygdala
– less S => less able to control impulsive + aggressive behaviour
- less S = more aggression
testosterone: (male sex hormone) {incs aggression}
- T = influences areas of the brain involved w aggression
- men = higher concentration > women
– men = normally more aggressive (archer - 2008)
- male-on-male aggression behaviour incs when T concentration = highest @ 21-35 yrs (daly + wilson - 1998)
evaluate the role of neural influences
biological explanation of aggression
the amygdala
(A) - supporting evidence from MRI scans [brain imaging method that produces images of brain structure]
- Sumer et al (2007)
– case study of 14yrs girl that displayed excessive rage + anger (in unwarranted situations)
- they found a tumor pressing against her amygdala thru MRIs
– this would trigger more nerve impulses from the amygdala to her hypothalamus
– hence -> more activity in the amygdala causes more aggression
(A) - research support from Mpakopoulou
- investigated (meta-analysis) 13 studies of patients w seizures (cos of abnormal amygdala activity)
- patients = had ‘amygdalotomy’ [disconnects amygdala from brain] => their agg levels decs after surgery
(D) inconsistent findings
- assumption: if there’s low activity in A, there should be few nerve impulses sent (so low aggression)
- but - animal studies of cats + monkeys:
– damaged amygdala caused more aggressive behaviour
(CP) - the studies shows a change in aggression (correlation)
– but not the direction other research has implied
(CP) - animal studies may not accurately rep human behvaiour / anatomy
- there are diif sub-reigons in the amydala - depends on which = damaged to affect aggression differently
(D) reductionist? -> ignores non-bio factors that contribute to agg {like social + environmental factors}
- more socially acceptable for boys to fight and be violent -> but not for girls ‘not appropriate feminine behaviour’
evaluate the role of hormonal influences
biological explanation of aggression
(A) - research support from Crocket for serotonin
- split a grp of ptts in 2
– 1st grp = given drug that decs S {should be more aggressive}
– 2nd grp = given drug that incs S {should be less aggressive}
- then ‘social decision-making game’ -> done to measure agg levels (thru behavior)
– were asked to divide money between pairs
- high S = likely to think fairly + divide money equally & weren’t agg when opponent took all money
- low S = likely to act more agg when opponent took most money & likely to take revenge next by taking all money
(A) research support from Dabbs et al (1987) for testosterone
- they measured T levels in 89 prison inmates & compared this w the level of violence of their crimes {correlational study as they’re looking for a R between em}
- results: higher levels of T => more violent crime (positive correlation)
–> more support for T (A) many studies compare the violence displayed by M+W
- M = more T –> display more agg > women
(CP) - correlation not = causality
– could be correlated due to another (unaccounted for) extraneous variable or they happen by chance
(D) inconsistent results for T -> so these findings haven’t always been replicated
(D) reductionist? -> ignores non-bio factors that contribute to agg {like social + environmental factors}
- more socially acceptable for boys to fight and be violent -> but not for girls ‘not appropriate feminine behaviour’
for genetic influence of aggression - what tests are done (w examples)
biological explanation of aggression
twin studies
- monozygotic = 100% same DNA
- dizygotic = 50% same DNA
- if 1 twin shows agg behaviour and so does the other = concordance -> shows genetic reasoning
– if the other twin doesn’t show this = discordance -> not genetic cause - maybe environmental?
- Cocarro et al (1997)
– conducted twin study observing aggressive behaviour
– MZ = 50% CC rate
– DZ twins = 19% CC rate - suggests strong genetic link to explain genetic behaviour
adoption studies
- (+) correlation between agg behaviour in adopted children + aggressive behaviour in bio parents -> genetic effect = implied
- (+) correlation between agg behaviour in kids + rearing family -> environmental effect = implied
- Hutchings + Mednick (1975) -> found 14,000 adopted boys from Denmark w criminal convictions had bio parents w convictions of criminal violence
– hence -> agg behaviour = hereditary (nurture = less impactful?) - Miles + Carey (1997) -> meta analysis of 24 twin + adoption studies displaying genetic basis of aggression
- findings: genes = influenced during childhood + adulthood
– environmental factors = more influential - Rhee + Waldman (2002) -> meta-analysis
- combined the results of 51 twin + adoption & concluded that aggressive anti-social behaviour = genetic contributions
the gene used for explanations of aggression
biological explanation of aggression
MAOA gene:
[produces a chemical that controls levels of neurotransmitters available @ synapse] -> [allows metabolizing of noradrenaline + S + D]
- if gene = dysfunctional -> neurotransmitters = not broken down in body
– if adrenaline = not metabolised => too much adrenaline -> may cause hypersensitivity in FoF response & can overreact to stimuli {perceives threats when they’re not present}
– S builds up (as it’s not broken down) => antisocial + agg behaviour
–> common w short allele
evaluate genetic influence in aggressive behaviour
biological explanation of aggression
(A) research support from twin studies
- Chritianses (1977) looked thru police records to find ppl w criminally violent activity w a twin
- he conducted a twin study -> 55% CC rate w MZ twins & 22% CC DZ twins
– hence there’s genetic cause of criminal violence => genes = impactful on aggression
(CP) CC rates = not 100% -> environmental factor also = influential
– undermines the reliability of twin studies
(CP) assume that environment = same impact on behaviour for MZ + DZ twins
(A) research support from adoption studies
- Hutchings + Mednick (1975) large number of adopted boys that displayed criminal behaviour & compared this to similar grp (norm)
- criminal boys = more likely to have criminal bio parents (in comparison to the control group
– considering that they couldn’t have any environmental influence - it must be due to genetics
(CP) adoption services try to match their new fam w their bio fam => environment may be the same -> undermining the role of genetics in adoption studies {lacks valdiity}
(A) research support for the MAOA gene
- Brunner et al (1993) -> observed 5 men from a fam, showing excessive aggression
- found that men = mutation of the MAOA gene
– gene = faulty => couldn’t produce any chemicals to break down neurotransmitters
- shows how MAOA gene affects aggression
(D) other factors affecting aggression
- aggression = complex behaviour -> many genes contribute to behaviour & they interact w environmental factors
- Caspi et al studied 500 male kids from birth to children to measure their agg + anti-social behaviour & DNA analysis to see genes
- found kids w short allele = more likely to display aggressive + anti-social behaviour
– but not all ppl w this allele behaved this way -> depended on the child’s environment -> only kids = maltreated by fam = agg
ethological explanation of aggression
A01
[scientific study of animal behaviour in a natural environement]
assumes: all members of same speicies = stereotyped behaviours that occur in specific conditions
- agg helps maintain social structures in animal groups
– defeated animal = forced to establish territory elsewhere - agg = innate & it’s a FAP
- animals spread out over wide areas = have to discover resources in diff places => decs comp pressures + possible starvation
- reasons for agg behaviour: compeition (for resources // land …) + anger + mating (showing dominance -> more appealing - mates can be protected) + threat + hunger
FAPs: -> they explain how agg = released
[Fixed Action Patterns = automatic + innate fixed set of behaviours that occur as a response to certain stimuli - throughout a species]
- each FAP has its own trigger
- produced by by neural mechanism IRM {Innate Releasing Mechanism} [the set of neurons which produces the FAP - involves brain regions involved w motor control -> like motor cortex]
– IRM recieves input form sensory recognition circuits -> this = stimulated by sign stimulus (specific external cue) => IRM coomunicates w motor control circuits to activate the FAP associated w that sign stimulus
** sign stimulus [ext cue] -> sensory recognition circuits (SRI) -> IRM -> FAP** - 5 main features:
– stereotypes -> unchanging sequences of behaviour
– universal -> same behaviour = found in everyone
– independent of indivudual learning -> behaviour = innate
– ballistic -> FAPs cannot stop after triggered
– specific triggers -> each FAP has specific sign stimulus
ritualisitic aggression
- not all agg beaviour = fighting
- ‘ritualistic’ signals shown as threat displays (used to scare off oponents)
- allows them to assess the sitch & decide to fight
– eg -> gorillas pound their chest
- RA = last step before fighting // leaving
- these behaviours = adaptive -> death decs population + threatens species’ existence
– when wolves fights -> the loser submissively exposes their neck (exposing jugular vein) = appeasement => inhibits prevent ‘winner’ from continuing
(CP) but killing conspecifics = not rare -> can be systematic
– male lion frequently kill cubs of other males - could be to establish dominance
A03 for ethological exps
(A) Timberg stickleback experiment (1951):
- sticklebacks develop red underbellies during mating season & when they’re aggressive towards other males entering their territories
- he presented wooden models in various shapes - some w red spot - to the fish
- found: the sticklebacks attacked regardless of shape if it had a red underbelly
– models = acted as trigger to fish
- sign stimulus = red underbelly
(D) aggression = not always ritualistic
- Goodall (2010) observed grp of chimps
- found that they fought + killed their neighbouring grp -> this = not ritualistic agg (so it’s unlikely to occur from natural selection)
– diif to explain from etho POV as high risk of injury towards attacking grp
(D) cultural differences {applies to evolutionary exp too}
- considering that agg = innate + FAP - it shouldn’t change over diff cultures
- Nisbett (1996) investiagte white males’ agg from southern + northen US
– ptts filled in questionnaire abt opinions of agg + violence
– then got confederate to insult ptts (to see reaction)
– results: [survey] -> both had similar opinions and agreed it was wrong & [exp] -> south men = more likely to display agg when insulted > north men
- hence showing cultural diffs in levels of agg
(D) only based on studies of animals
- they lack generalisability to humans -> they way humans display agg may not be the same way animals do
- complex behaviour in ppl = usually due to interaction between environ + genetic factors
what are the 2 evolutionary explanations of human aggression
[argues that reproductive challenges faced by ancestors can explain current aggressive behaviour]
- aggresion = adaptove response
– adaptions = fundamental + universal components of human nature
- makes inheritied psychological mechansims to improve odds of passing down genes (survival)
- argues that women don’t face much aggression (As there are plenty of men to reproduce with) - so they haven’t evoloved to be aggressive
– they worry about keeping their baby safe - they look for these good qualities in men (found in aggressive men)
- argues that women don’t face much aggression (As there are plenty of men to reproduce with) - so they haven’t evoloved to be aggressive
sexual jealousy:
-Daly + Wilson (1988) –> men = evolved diff stratergies to deter partners from comiting adultery
– eg -> ranges from vigilance [asking who they chat to // reading txts] to violence
- this = result of male jealousy + paternal uncertainty
- if a man = cuckhold [the husband of an unfaithful wife] => may unwittingly invest in rearing kids that aren’t his
- male jealousy = evolved to prevent infidelity {reduces risk of cuckholdry}
- Buss (1988) –> argues that men = developed stratergies for mate retention
- direct guarding [restricting her movements]
- negative inducements [financial control // threats of violence] -> prevent her straying
(A) Wilson et al (1995) -> support for the link between sexual jealousy + mate retention + violence
- from questionnaire (CP) -> women = implied they had jealous partners = 2X likley to have expeirenced violence
aggression in warfare
- 2 (A)s of war = expansion / defence of territory + higher status
– this allows victors to attract Fs => more reproduction
- Kelly + Dunbar (2001) heroic bravery shown by war soldiers = attractive
– Fs like this trait -> these genes = advantageous for offspring
- Lehamnm + Feldman (2008) -> more aggressive men = win wars + pass on their genes (survival) => increasingly aggressive species
evaluate evolutionary exps of aggression
(A) research support from Buss et al w a cross-cultural queationnaire-based study
- according to evo exp - men fear sexual infidelity (this produces a child that’s not theirs and they may have to care of it) + women fear being abandoned
- Buss told people to imagine they were in a R => would it hurt more if they sexually cheated, or emotionally cheated
- reffering to the evo exp - it’s expected that men would be more effected by sexual cheating + women = hurt more by emotional cheating (as they’re more likely to abandon them)
- results:
– 51% men + 22% women = more upset by sexual cheating
- researchers argued that this not = due to social // environmental factors - but rather genetics + evo
(CP) lack validity
– questionnaire may not exactly measure what the ptts feel IRL (lacks accuracy)
– social desirability bias
(CP) 49% men = more ffected by emotional infidelity - undermines evolutionary explanation
(D) ignores environmental factors (social norms) - Prinz argued: sex diffs = caused by diffs in social norms that adults teach - when reprimanding boys - adults normally physically harm (shows that physical violence = accpetable) - with girls its more verbal - hence - boys = more physically aggressive whereas girls = more verbally aggressive
(D) gender bias
- alpha bias - evo exp exaggerate the diffs between genders
- not all men are aggressive + seek dominance -> (seen in the 49% men in Buss’ study)
- some women = aggressive (thru verbal taunting)
(D) ethical issues
- when men yell + abuse GFs - its due to evolution to prevent infidelity
- this exp argues that men shouldnt be responsible for their aggressive actions
- modern world - social norms have changed - not acceptable to act aggressively
– unethical for harming others to be normal behaviour
social learning theory explanation of aggression
social explanation of aggression
[according to SLT - behaviour = learned thru observation]
[states that aggression = learnt through a mixture of indirect + direct learning reinforcement]
- ppl learning aggression thru observing + imitating aggressive role models
- normally - one identifies w their role model
-> indirect reinforcement - child = likely to imitate if agg behaviour = rewarded {vicarious reinforcement}
– hence they’re less likely to do it if the RM = punished for {vicarious punishment}
-> direct reinforcement - one = more likely to repeat actions if rewarded for it {positive reinforcement}
- & less likely to repeat if it leads to a (-) outcome (like punishment) {negative reinforcement
- in order to repeat behaviour -> need to pay attention + remeber it [retention]
- agressiveness = influenced by ‘self-efficay [self confidence] -> the higher this is => more likely to replicate new behaviour
factors influencing SLT (observational - indirect)
- identification (more likely to imitate if they identify w role model
- vicarious reinforcement (repeat behaviour if model = rewarded for their behaviour)
mediational processes needed for SLT
[determine if ppl imitate agg behaviour]
- attention -> (focused on the behaviour u want to remeber?)
- retention . memory-> (accuractely remember behaviour?)
- reproduction -> (ability to repeat behaviour?)
- motivation -> (desire to learn behaviour?)
evaluate social learning theory as an explanantion for aggression
social explanation of aggresssion
(A) supporting research from Bandura (1961)
- Bandura conducted a lab exp to test if kids would imitate adults who modelled aggressive behaviour
- Children were split into 3 groups ->One group watched an adult display aggressive behaviour towards a Bobo doll
– (reslts) -> kids = more liekly to display aggression
- one group watched an adult display non-aggressive behaviour towards the doll
- the third group didn’t watch an adult at all. Some children watched a female model, and some watched a male model -> He then put each child in a room with the Bobo doll and observed their behaviour.
- he did a second exp in 1963 that showed kids = more likely to imiate the adults behaviour if the adults were rewarded afterwards
(CP) the bob-doll = not living -> hence it can’t retaliate
– this = unrealistic & normally ppl would fight back (acting as negative reinforcement to deter this behaviour)
- also, kids may display demand charactersisitc // not act truthfully due to the artificial environment => low ext validitty
(CP) also bandura could only observe and infer behaviour as u can’t acurately measure mediating factors
(A) research support from Gee + Leith (2007)
- analysed penalty records from 200 NHL games
- they suggested players born into north america = exposed to more agg models during youth & less likely to be punished for agg play compared to EU
- NA players = less likely to be penalsed for aggressive play
- imitating role models + motivation for agg (to win) + vicarious reinforcement (no punishment)
(CP) there way be cultural differences
- NA = individualsitic culture -> so this may not be generalisable - limiting reliability
(A) real life application
- ‘act against violence’ = intervention programme
– aim = educate parents + others abt danger of being role agg models -> encourages them to provide positive role models
- after completing the programme => parents demonstrated inc positive parenting & stopped physical punishment
(D) SLT = reductionist as it underestimates the influence of biological factors
- Bandura acknowledges genetics influence the urge to be agg (it’s instncitve in nature)
– but states that agg = primarily learned & = outcome of nature
- despite the establishment of powerful genetic + evolutionary + nerual + hormonal influences on agg -> SLT barely acknowledges them
(SLT) de-individuation theory
social explanation of aggression
[when ppl lose their sense of ifentity + responsibility when in a large group]
- in norm settings, there are consequences (being told off // judging - social norms) - >tis hihibits desires to act agg
- in a large group - one may feel anonymous => becomes less aware of consequences (thinks they can;t be responsible for their actions)
- people become less inhibited + less worried abt breaking social norms
factors affecting de-individuation:
- size of the group
– small group -> still identifiable & in big group = anonymous + less indentifiable
– larger the group = more likely experience de-individuation
- anonymous clothing
– leads to more aggressive behaviour
evaluate de-indivuation theory
social explanation of aggression
(A) research support from Zimbardo’s prison experiment
[conducted a controlled experiment in a fake prison to investigate if conformity = due to identification to social roles]
- both prisoners + guards were in uniform of some sort -> de-individuation
– guards = de-individuation due to anonymous clothing (esp w sunglasses) => acted more aggressively
– large group of guards (to act agressively)
(A) study support from Zimbardo (1969)
- 2 grps of ptts = told they were taking part in a learning task
- told to administer shocks to another ptt to aid learning -> but there was no other ptt (they were being decieved)
- CONTROL grp = introduced to eachother + name tags
- EXPERIMENTAL grp = wore hoods + no name tags (anonymous)
- findings:
– more anonymous = more shocks (more aggressive due to loss of individual responsibility)
-> hence supporting de-indivduation theory
(A) reasearch support form Mullen
- lynching [when ppl from a large social groups target + kill members of a smaller social group]
- Mullen researched 60 US newspaper reports on lynching, from 1899-1946
- found: the larger the group => the more violence + aggression
– hence, supporting the idea of how group size influences agg {larger group = feels more anonymous = experiences de-individuation}
(D) inconclusive evidence
- 2 researchers conducted a meta-analysis of 60 studies about effects of de-indivduation’s on agg
- found: sometimes, larger group => more agg, if pppl saw the agg as justified
- however, sometime a larger group => ppl = more kind (social desirability?)
– prosocial behaviour = [ppl in a helpful manner] -> this undermines de-in theory
- de-in = weak effect on agg
(D) doesn’t consider gender differences
- studies (men vs women) show that de-in only incs agg in men
- de-in theory doesn’t mention if diff genders react diff (unlike bio + evo exps)
