1 of 1AggressionSocial Psychological Approaches to Explaining Aggression – SLTBandura – importance of modelling or vicarious learningWe observe someone else’s aggression being rewarded.Observation Imitation ReinforcementFour essential pre-conditions: Attention, Retention, Reproduction, MotivationSo cognition is important in terms of assessing the model, the self and the situation to determinewhether aggression will be imitated.Other important factors: Self efficacy – the belief a person has about their own abilities.Characteristics of the model – Status, SimilarityReciprocal determinism - the 2 way relationship between an individual and their environment.How would each of these factors affect the likelihood of aggressive acts occurring?Evaluation of SLTThe Bobo doll studies - Children watched an adult model behaving aggressively towards aninflatable doll, then their own behaviour with same doll was observed.BUT What else can you really do with a Bobo doll? Is the study valid then?Further support for SLTBandura et al (1961) showed nursery age children a tv programme in which Johnny won’t let Rockyplay with his toys.Version 1 – Rocky hits Johnny and throws toys at him. Voice-over declares Rocky victorious as heleaves, taking toys with him.Version 2 – When Rocky tries to retaliate, Johnny hits him.Children then recorded playing for 20 minutes.Those who had seen version 1 were far more aggressive in their playWhat about studying aggression in a non-play context?Patterson et al (1982) studied 19 children aged 3 – 12 who had been referred to specialists due totheir socially aggressive behaviour.Parents had unwittingly both modelled aggressive behaviour by punishing them physically andreinforced it by giving in to tantrums.Parents were trained to model appropriate behaviour and use positive reinforcement for goodbehaviour as well as using more effective discipline (naughty step).Parents reported treatment as ‘very effective’.A biological basis for SLT?In the 90’s Rizzolatti et al discovered a group of cells in the brain that they named ‘mirror neurons’These are activated when we see another person performing a meaningful action.These are the same neurons that would be activated if we carried out the task ourselves.Deindividuation Theory of AggressionDeindividuation – to lose one’s sense of individuality and identity.Can occur in 2 main ways – Becoming part of a crowd OR Identifying with a particular role ( oftenaided by wearing uniform or mask)Can be used to explain aggression which occurs when in a group.Le Bon (1896) – individuals are more likely to behave in aggressive manner when part of a largeanonymous group. A collective mindset is created and the group can become a ‘mob’.Individuals feel less identifiable in a group, so the normal constraints that prevent aggressivebehaviour may be lost. The shared responsibility for action reduces individual guilt.Diener (1980) Deindividuation occurs when self-awareness is blocked by environmental events.Critical factors include: Strong feelings of group membership, Increased levels of arousal, Focus onexternal events, Feeling of anonymity.The deindividuated individual is trapped in the moment, perception of time is distorted and theyare unable to consider consequences.Increased arousal, External focus, Strong group feelings, Sense of anonymity LEADS TO Reducedself-awareness WHICH LEADS TO DEINDIVIDUATION.Prentice-Dunn & Rogers (1982) Modified Diener’s theory to distinguish between:
2 of 2Public self-awareness - concern over the impression of yourself you are presenting to others whenyou are aware of being judged.Private self-awareness – your sense of self, consisting of thoughts, feelings, values and internalstandards of behaviourReduction in either can result in aggressive behaviour, but only reductions in private self awarenesscan lead to genuine deindividuation.EvaluationZimbardo (1973) Stanford Prison experimentZimbardo (1969) Explored deindividuation in female undergraduates.Group 1 dressed in white lab coats with hoods over their facesGroup 2 wore large name tags.All pps observed a woman being interviewed and evaluated her performance by administeringelectric shocks.Condition 1 – pleasant interviewee, condition 2 – obnoxiousGroup 2 shocked the obnoxious interviewee more than the pleasant oneGroup 1 (deindividuated) shocked both interviewees equally.Zimbardo concluded that deindividuation increased aggression, making it indiscriminate and not atall influenced by individual characteristics.Ellison et al (2005) Field experiment – drivers of convertibles with tops down beeped more thanthose with tops up.Driving simulation exp’t with 289 psych student pps.Measured aggressive driving (speed, jumping red lights, collisions etc.) in tops up / tops downconditions.More aggression shown in tops down (anonymous) condition.Rehm et al (1987) Aggression in handballDeindividuation was created by giving one team orange shirts, whilst other team wore own clothes.In boy teams, uniformed teams were more aggressive than non-uniform.In girl teams, no differences found.Researchers concluded that uniform > loss of individuality > deindividuation.Cross cultural evidenceWatson (1973) – 24 cultures. Warriors in face and body paint more likely to kill, mutilate andtorture captured prisoners.Silke (2003) – violent assaults in Northern Ireland. 206 / 500 cases carried out by offenders wearingmasks or disguises. Anonymous attackers were more prolific and inflicted more serious physicalinjuries than identifiable attackers.Explanations of Institutional AggressionPrisons - The Guardian in 2003 highlighted abuse of inmates in Wormwood Scrubs. Beatings, mockexecutions, death threats, choking, racist abuse.Educational Settings - Both teachers and students victims of rape, armed robbery, aggravatedassault and verbal threat. Also, School shootings – Columbine, Dunblane, Germany.Healthcare Settings - Carers and mental health nurses most at risk. Patients also easy targets forkillers such as Beverley Allitt and Harold Shipman.ExplanationsDe-individuation - anonymityIdentification with a role - uniformSituational variables – overcrowding, ‘us and them’ normsExamples of institutional aggression in prisonsZimbardo (1973) – Stanford prison experiment / Abu GhraibLockwood (1980) – 2/10 prisoners sexually assaulted. Both victim and assailant ‘heterosexual’.Sexual assaults used as degradation and punishment.In prison, rape is about social control, not sexual gratification and does not count towards sexualidentity.Examples of institutional aggression in educational settingsFraternities and sororities were established as support networks for U.S. college undergraduates.‘Hazing’ - ritualistic harassment / abuse of an individual or group involving burning, branding,kidnapping, sexual abuse to prove their ‘worth’.
3 of 3Nuwer (1990) hazing contributed to death and serious physical injury including paralysis and is nowillegal in most states.Martin & Hummer (1989) studied sexual assault in fraternities and discovered that sexual violenceagainst women was actively encouraged. Postal questionnaires were sent to sororities – only 28%response rate. Half respondents had experienced sexual coercion, 24% victims of attempted rape,17% victims of full rape. Rapes had occurred in frat houses or frat functions.Ecological ExplanationBlyth (1980) gave questionnaires to 13 yr old students to assess perception of anonymity anddanger levels within school. 34% of sample had been victims of bullying. More of these childrenwere at junior high, where they would be the youngest in large, crowded institutions. Fewerchildren at elementary school (where they were the eldest) felt such isolation and fear.Situational variablesexplained Matthews et al (1979)As crowding increases, so does aggression, but only up to a point. After this, further increases incrowding lead to decreases in aggression.Examples of institutional aggression in healthcare settings.Most commonly associated with psychiatric units. Includes Biological, social and environmentalinfluences. Key Study includes Rosenhan (1973) ‘On Being Sane in Insane Places’Biological Explanations of AggressionDefining AggressionKingsbury et al (1997) – categorise aggression as either:Instrumental – the goal is reward (eg, recognition by gang members, acceptance into afraternity)Hostile – the goal is harm (eg, in response to a threat or insult)Berkowitz (1994) – distinguishes betweenInstrumental aggression (purposeful, goal directed, learned behaviour)Reactive aggression (emotional, unregulated, occurs in response to frustration)McEllistrem – differentiate between the different biological origins of:Affective (reactive) aggression – an evolved automatic response to provocation or threatPredatory (pro-active) aggression – goal directed and pre-meditated, often associated withcrimes such as assault, murder and rape.The Role of Genetic Factors in Aggressive BehaviourSelective breeding of some animals for aggression has been carried out with bulls, chickens, dogsand even fish!Lagerspetz (1979) reared baby mice in isolation and later measured their aggressive behaviour withother mice. They were labelled as Turku aggressive (TA) or Turku non-aggressive (TNA). Mice wereinterbred so by 19th generation, rates of aggression in TA mice were 52% whilst in TNA mice, only5%. TA mice had heavier testes and forebrains.Twin studies - In humans, it is much more difficult to separate the effects of heredity andenvironment. Variability in findings of concordance rates for MZ twins reared together. BUT, overallgreater association of aggressiveness with MZ than DZ twins whether reared together or apart.Rhee & Waldman (2002) variability may be due to methods of assessing aggressive behaviour.XYY syndrome - Jacobs et al (1965) – incidence of XYY in prison inmates is 3%, whereas in normalpopulation is approx 0.1%. These men were taller, had higher levels of testosterone and lowerlevels of intelligence than non XYY people. Witken et al (1976) disputed the link with aggression.MAOA gene and aggression - MAOA gene regulates Monoamine oxidase A enzyme in the brain,which breaks down serotonin, noradrenaline and dopamine.Brunner et al (1993) discovered mutation in gene in Dutch family, passed on through mothers tosons.The Role of Neural and Hormonal Mechanisms in AggressionPhineas Gage - One of the best examples of how brain injury can influence aggressive behaviour isthe case of Phineas Gage. Working on a railway in 1848, he had an accident in which a tamping ironwent up through his face , behind his left eye and out through the top of his head. He survived theaccident, but his personality was changed, including a huge increase in aggression.Neural Mechanisms – Brain structureNormal aggressive behaviour is not dependent on separate brain structures, but interaction of asystem of structures - Organised hierarchically and moderated by the pre-frontal cortex.
4 of 4The Amygdala affects the Hypothalamus and the Periaqueductal grey.The Role of the AmygdalaKluver-Bucy syndrome – taming effect found in rhesus monkeys by removing part of the temporallobes and therefore destroying the amygdala.Narabyashi et al (1972) – 43 / 51 patients whose amygdala was destroyed through psychosurgeryshowed reduced aggression afterwards.Mark & Ervin (1970) – case study of female patient behaviour following electrical stimulation ofamygdala. She exhibited facial grimacing, became very angry and flung herself at the wall.Ashford (1980) – temporal lobe epileptics often become aggressive, attacking furniture and people.Wong et al (1997) – criminals with violent tendencies have reduced size amygdalaVan Elst et al (2000) aggressive patients with temporal lobe epilepsy, amygdala had lost 20% of itsvolume.BUTMuller et al (2003) showed 6 male psychopaths and 6 male controls a series of positive andnegative pictures whilst in MR scanner. Found increased activity in the amygdala.The exact role of the amygdala in aggression is unclear, but it is certainly a significant one. Researchsuggests an interaction between the amygdala and the pre-frontal cortex.The Role of the Prefrontal CortexRegulates the emotional responses driven by the amygdala.Damage to prefrontal cortex results inimpulsivity, immaturity and loss of control.Anderson et al (1999) – damage during infancy related to aggressive behaviour as adults. Casestudies comparing early onset damage with adult onset damage to frontal lobes. Early onsetpatients also performed poorly on tests of moral and pro-social reasoning.Raine et al (1997) – investigated brain activity of 41 murderers using PET scans. Found reducedglucose metabolism in prefrontal cortex, suggesting this brain area is less active than in normalcontrols.Volkow et al (1995) found violent psychiatric patients had reduced cerebral blood flow to prefrontalcortex.During the 1940s, frontal lobe lobotomies were performed with startling regularity ; partly becauseof the ‘calming’ effect on patients with a range of mental health problems – from depression toADHD to OCD.The Role of NeurotransmittersThe neurotransmitter serotonin influences aggressive behaviour. In research with vervet monkeys,reducing serotonin levels resulted in increased aggressive behaviour, whereas increasing serotonindecreased the aggressive occurrences. Drugs to raise serotonin levels, such as trytophan have beengiven to juvenile delinquents and unpredictable institutionalised patients. So… the higher theserotonin level, the lower the aggression. But this research only found a correlation.Hormones and Aggression – TestosteroneBeeman (1947) castrated male mice and found that aggressiveness reduced. He later injected themice with testosterone which re-established their aggressiveness. Castration has since been usedas a method for making domestic and farm animals more manageable.Testosterone is also clearly related to aggression in humans.Dabbs et al (1995) – measured testosterone in saliva of 692 adult male prisoners. Found higherlevels in rapists and violent offenders than in burglars and thieves.Dabbs et al (1996) – looked at 12 fraternities in 2 universities. Members of fraternities with highestlevels of testosterone were described as boisterous and macho, those with lowest were attentiveand helpful.The same effects of testosterone are also found in women.Dabbs et al (1988) – female prisoners. Testosterone highest in cases of unprovoked violence butlowest where violence was defensive (eg. In domestic abuse cases)Other research has found conflicting results, but this is to do with the operationalization of‘aggression’.Aggression as an Adaptive ResponseEvolutionary explanations of human aggressionThe adaptive and functional benefits of aggressive behaviour must outweigh the possible costs.(Buss &Duntley 2006)Status conflicts and access to mates. Also Indirect – gossip, rumours, ostracising people from group.
5 of 5Aggression in males. Primary motivator is acquisition of status. In the EEA, good hunters accruedresources and skilled fighters could ward off rivals = ATTRACTIVE TO FEMALES.High status males monopolise females Low status males at risk of not producing offspring L.S.males indulge in high risk strategies to compete for status Success enhances reproductivesuccessDaly & Wilson (1985) - murders in Detroit in 1972 - The motive behind most of the conflicts wasstatus. Victims and offenders were unemployed and unmarried young men, LOW STATUS ANDWITHOUT A MATE.Sexual Jealousy and Infidelity in MalesMALE ON MALE AGGRESSION - Daly & Wilson (1985) – 58 / 214 cases of murder motivated bysexual jealousy. Confidence in paternity and warning to potential rivals.MALE ON FEMALE AGGRESSION - Designed to deter the female from indulging in behaviour not inthe male’s interest. Miller (1980) – 55% battered wives cited jealousy as reason for husband’sbehaviour. Often unfounded, based only on suspicion and fear.MALE ON CHILD AGGRESSION - Link to parental investment. Males reluctant to expend energy andresources in raising offspring of another male. BUT refer to bad dad / good step-dad study…Young (1978) Asked students to describe their likely reactions to a jealousy inducing scenarioMen – respond angrily, become drunk, threaten their rival.Women – cry, pretend not to care, try to increase own attractiveness to regain male attention.Aggression in females For females, the costs of aggressive behaviour exceed the benefits. Themothers’ presence is more critical to offspring survival than the father’s. (Campbell 2002) Highstatus, dominant, aggressive females not preferred as mates so no adaptive value in overtaggression. BUT low risk, indirect strategies such as gossiping, name calling and ostracising todecrease attractiveness of competing females developed to reduce risk of physical injury.Griskevicius et al (2009) gave students scenario of person of same sex spilling a drink on them at aparty and not apologising. Majority of men would respond with direct aggression (eg, pushing theother man) Only a quarter of women would do so, most women most likely to walk away.Women most likely to use direct aggression when competing for resources that will aid theirsurvivalExplanations of Group Display in Humans 1 WARMen only willing to fight as part of coalition if confident of victory.In Yanomamo of Amazon rainforest, frequent fighting between villages over abduction of women.(Chagnon 1968)Success in battle > high status. Successful warriors had more wives and children.Young men who had not killed were rarely married.Pinker (1997) – In WW2, Germans raped women in concentration camps.More than 20,000 Muslim girls and women raped as part of genocide programme in Bosnia. Aimwas to make the women pregnant and raise the children as Serbs, or terrorise them into fleeing theland (Allen 1996)Evolutionary theory can explain tribal warfare where casualties are few and rewards, great. But inrecent human history, prolonged warfare results in significant losses on both sides.Wrangham (1999) – military incompetence is result of adaptive self-deception. Positive illusionsabout winning will improve cohesion and co-operation and may bluff the opposition BUT may alsolead to inaccurate assessment of own and opponents’ abilities.Explanations of Group Display in Humans 2 SPORTS EVENTSRitualised form of aggression – benefits of success available to competitors with reduced risk ofphysical harm / death. Winning team hold high status, team members seen as desirable mates.In certain games (eg, rugby union) a level of aggression is sanctioned but some players still breakthe rules. Maxwell &Viscek (2009) – questioned 144 rugby union players about their aggression inthe game. Those high in professionalism placed more emphasis on winning and were more likely touse unsanctioned aggression. Cheating (and not getting caught) is adaptive.Victory in matches also brings status to fans. Cialdini et al (1976) ‘basking in reflected glory’ – aftera university football team had performed well, students more likely to wear university scarves andsweaters.Football hooliganism - Marsh (1978) – football hooliganism is human equivalent of ‘ceremonialconflict’ in animals. Exclusively male, ritualised symbolic aggression restrained by desire tominimise harm and death. Intention is to humiliate opposition and secure submission.