Aggression

What is the limbic system?

What is the limbic system?

Subcortical structures in the brain thought to be closely involved in regulating emotional behaviour including aggression

What are the components of the limbic system

• hypothalamus

• amygdala

• hippocampus

• thalamus

what is the role of the amygdala in the limbic system

key role in assessing and responding to environmental threats and challenges - the reactivity of the amygdala has proven to be a reliable predictor of aggressive behaviour

Give a weakness of the limbic system as an explanation for aggressive behaviour

Studies indicate that the amygdala does not operate in isolation in determining aggression, it appears to be connected to the orbifrontal cortex which is not part of the limbic system - therefore, the limbic system is not the only brain structure involved in aggression

briefly outline the role of serotonin as a neural mechanism involved in aggression

serotonin is an inhibitory neurotransmitter - slowing down neuronal activity. Normal levels of serotonin = reduced firing of neurons = greater levels of behavioural self control. Not enough serotonin = too much neuronal firing = more impulsivity, increasing your likelihood to engage in aggressive behaviour.

Give a strength of serotonin activity as an explanation for aggressive behaviour

Berman et al (2009)

Drugs that increase serotonin activity decrease aggressive behaviour. Control group took placebo, others took serotonin increasing drug - control were more aggressive (however, only for participants w aggressive histories)

briefly outline testosterone as a hormonal mechanism in explaining aggression

reliable observation that men are generally more aggressive than women - male sex hormone testosterone has a role in regulating social behaviour. Animal studies have demonstrated that experimental increase in testosterone leads to aggressive displays - castration led to a reduction in aggression.

Dolan - violent offenders had higher levels of testosterone.

Give a weakness of testosterone levels as an explanation of aggression.

Other hormones - most specifically cortisol probably have an impact on aggressive behaviour

Carre and Mehta (2011) dual hormone hypothesis claims that testosterone only leads to aggressive behaviour when cortisol is low and when cortisol is high, testosterones influence of aggression is blocked.

give a brief outline of the findings of twin studies related to aggressive behaviour

suggests that heritability accounts for at least some aggression.

Researchers find concordance rates of about 50% for MZ twins and 19% for DZ. Obviously heritability cannot be the only factor here, otherwise the concordance rates would be 100% and 50%

give a brief outline of the findings of adoption studies related to aggressive behaviour

Rhee and Waldman (2002) - meta analysis of adoption studies of direct aggression and antisocial behaviour - found that genetic influences accounted for 41% of the variation in aggression (more or less in line with twin study findings)

what is L-MAOA

Low functioning monoamine oxidise A

enzyme in the brain, ‘mops up’ neurotransmitters after synaptic transmission - especially serotonin. Disfunction in MAOA can effect serotonin levels in the brain.

Outline Brunner’s (1993) study into L-MAOA

studied 28 male members of a large, Dutch family who all had aggressive and violent histories , all the members with violent histories had abnormally low levels of MAOA.

Outline Stuart’s (2014) study into L-MAOA

studied 97 perpetrators of intimate partner violence, those with the lowest levels of MAOA committed more and more violent IPV.

Outline Frazzetto’s (2007) findings in his study of gene-environment (GXE) interaction

Founds an association in his sample between L-MAOA and higher levels of aggressive behaviour, but only in participants who had experienced some kind of serious psychological trauma.

List 3 genetic factors in aggression

• heritability - twin & adoption studies

• MAOA gene

• GXE interactions

Give a strengths for genetic explanations for aggression

• Research support for MAOA gene - If low MAOA = aggression then high MAOA should = prosociability Mertins (2011) proved this

Give 3 weaknesses for genetic explanations for aggression

• difficult to standardise/ operationalise aggression in a way that ensures it is measured the same in every study

• Difficult to isolate genetic factors - gene and environment interaction make it impossible to determine how much influence genetics have

• Unlikely to be any sort of single candidate gene - Vassos: meta analysis found no evidence of singular or small group of genes and predicts it’s more like hundreds and thousands working together in a complex manner

Define ethology

study of animal behaviour in natural settings

outline the ethological notion that aggression is adaptive

aggression is beneficial to survival as an animal is rarely killed - rather forced to move meaning species spread out, reducing competition pressure.

Aggression is also used to establish dominance hierachies.

Define ritualistic aggression

Aggression is frequently used as a display of power and strength rather than any violence actually being involved, animal are rarely hurt. Aggressive encounters also often end in ritual appeasement displays - the loser making themselves vulnerable to the victor.

Define Innate Releasing Mechanism

A biological structure or process which is activated by an external stimulus that in turn triggers a fixed action pattern

Define Fixed Action Pattern

A sequence of stereotyped, pre-programmed behaviours triggered by an innate releasing mechanism.

List Lea’s (1984) 6 characteristics of FAPs

• Stereotyped - relatively unchanging

• Universal

• Unaffected by learning

• Ballistic - once behaviour is triggered it follows an inevitable course and cannot be stopped or altered

• Single purpose - only occurs in a specific situation, not in any other

• A response to an identifiable specific sign stimulus

Outline Tinbergen’s (1951) research into IRMs and FAPs

Study into male sticklebacks - highly territorial in mating season and develop a red spot on their underbelly. If another male (identifiable by the red spot) an FAP is triggered, Tinbergen presented sticklebacks with wooden models of varying shapes - all with red spots. Regardless of shape, if the model had a red spot, the stickleback would aggressively display - if there was no red spot, there was no aggression even if the model looked realistically like a stickleback.

Give a strength of the ethological explanation of aggression

Supporting research - Validity supported by evidence that demonstrates the genetic and physiological basis of aggression - Brunner etc.

Give 3 strengths of the ethological explanation of aggression

• Cultural differences in aggression - rates of aggression are different in different locations - e.g. north/south divide in homicde in USA. Ethological theory views aggression as instinctive so it’s difficult for it to explain how culture can override this.

• FAPs are not that fixed - Hunt (1973) sequences of behaviours that appear to be fixed are actually heavily influenced by environment. FAPs are more flexible, varying slightly from one animal and situation to another.

• Unjustified generalisation to humans - neither lorenz or tinbergen studied higher mammals, but generalised their findings in unsimilar animals to humans.

Outline the evolutionary explanation of sexual jealousy

unlike women, men can never be totally sure if they have fathered a child - paternity uncertainty leads to threat of cuckoldry. Psychological mechanisms have developed to prevent this - sexual jealousy is higher in males, driving aggressive strategies males sometimes employ to retain their partners.

Outline Shackleford (2005)

Studied IPV - 107 married couples completed questionaires. Men completed mate retention inventory which assessed mate retention behaviours in various categories and women completed the spouse influence report which measured the extent of their partners violence.

there was a strong positive correlation between men’s reports of their mate retention behaviours and women’s reports of their partner’s physical violence - retention behaviour reliably predict use of violence

outline the evolutionary explanation of bullying

bullying occurrs because of a power imbalance. Evolutionary ancestors may have used bullying as an adaptive strategy to increases their chnaces of survival

Volk(2012) - argues that characteristics involved in bullying are attractive to the opposite sex and is involved in methods to secure greater reproductive success

Give 2 strengths of the evolutionary explanation of aggression

• Accounts for gender differences - evolutionary theroy can explain why males typically engage in more aggressive behaviour than women and can explain differences in aggression, women commit less physical aggression because they are motivated to take less risk and this may explain why females typically engage in verbal aggression more.

• Real life applications - an evolutionary undertsnadin of bullying as an adaptive behaviour to devise more effective antibullying interventions. If bullies are aggressive in order to gain something - they are unlikely to give up this behaviour without some kind of reward for prosocial alternatives.

Give two weaknesses for the evolutionary explanation of aggression

• Cultural differences - !Kung San tribe have negative attitudes towards the use of aggression and it’s extremeley rare in their society - surely if aggression was completely innate then we wouldn’t be able to discourage it out of children?

• Methodological issues - extremely difficult to test hypotheses about the evolution of behaviours to solve problems of adaptation in our evolutionary past. Most research is therefore correlational - cause and effect cannot be clearly or reliably established

Outline Dollard’s (1939) frustration aggression hypothesis

frustration always leads to aggression and aggression always the result of frustration - based on the psychodynamic concept of catharsis

frustration = aggressive drive = aggressive behaviour = aggressive drive satisfied through cathartic release.

aggression may be displaced in one of three situations

• cause of frustration is abstract

• cause of frustration is too powerful

• cause may be unavailable at the time

Outline Geen’s (1968) study into the effects of frustration on aggression

Male university students were given the task of completing a jigsaw puzzle, their level of frustration was manipulated in one of 3 ways

• puzzle wa simpossible to solve

• ran out of time because a confederate kept interfering

• confederate insulted the participant as they failed to solve the puzzle

Then participants were asked to gicve electric shocks to the confederate when they made mistakes on a different task - insulted particpants gave the strongest shocks on average followed by the interfered group. All three groups selected more electric shocks than an unfrustrated control group

Outline Berkowitz’s (1989)

aranged for student participants to be given electric shocks in a laboratory setting, indivudual who gave the shocks was a confederate, participants then had the opportunity to turn the tables and give shocks to the confederate. The number of shocks given depended on the presence or absence of weapons in the labs, when guns were present - aggression was higher

Give two strengths of the frustration aggression hypothesis

• Marcus - Newhall (2000) - meta anlaysis of 49 studies of displaced aggression, concluded that displaced aggression is a reliable phenomenon.

• Real life application to gun control - Berkowitz’s study has featured in gun gontrol debates in the states

Give two weaknesses of the frustration aggression hypothesis

• Bushman (2002) - aggression is not cathartic. Study involved participants taking aggression out on a punching bag became more angry and aggressive rather than less - casts doubt on validity of central assumption of hypothesis

• Negative affect theory - frustration does not always lead to aggression and aggression can occurr without. Hypothesis reformulated by Berkowitz to be negative affect theory: frustration is one of many averse stimuli that create negative feelings

Briefly outline Bandura’s social learning theory (1973)

aggression can be learned directly through mechanisms of operant conditioning involving positive and negative reinforcement and punishment. Aggression, as all social behaviour is learnt through observation. If an observer sees a model being rewarded for behaviour, they are more likely to repeat the behaviour.

Four cognitive conditions are needed for observational learning to take place

• Attention

• Retention

• Reproduction

• Motivation

What is the role of self efficacy in Bandura’s social learning theory of aggression

self efficacy is the belief that our actions will achieve a desired goal - a child’s confidence in their ability to be aggressive grows as they learn that aggression can bring rewards - our sense of self efficacy develops with each successful outcome of aggression.

Briefly outline Bandura’s research into aggression

young children individually observed an adult model assaulting an inflating plastic toy ‘bobo doll’, they were then frustrated by not being allowed to play with some nice looking toys, then were taken to another room where the bobo doll and some other toys were - without instruction, many of the children immediately began attacking the dolls.

give two strengths of SLT as an explanation for aggression

• Real-life applications - to portrayal of aggression in media and the potential dangers of viewing violent media

• Practical application to preventing aggression - understanding that in some cases, changing environment and opportunities for observation of aggressive models can prevent aggression

Give a weakness of SLT as an explanation for aggression

• Cannot explain reactive aggression - not all aggression is carried out in order to gain something as SLT suggests. Reactive aggression is used to achieve nothing other than retribution.

Briefly outline deindividuation as an explanation for aggression

when we are individually identifiable our behaviour constrained by social norms - in a crowd we lose restraint and have the freedom to behave in ways we wouldn’t usually as we lose out sense of individual identity and responsibility for our behaviour.

Behaviour is typically rational and normative but when we are in a crowd our behaviour becomes deindividuated, emotional and irrational “anonymity shapes crowd behaviour”

the higher your self awareness, the less likely you are to commit socially unacceptable behaviour, deindividuation = less self awareness.

Briefly outline procedure and findings Dodd’s (1985) research into aggression

• asked students what they would do if they were completely anonymous for a day

  • 36% were antisocial acts

  • only 9% prosocial

give two weaknesses and one strength of deindividuation as an explanation for aggression

• de-individuation does not always lead to violence.

  • Gergen et al - ‘deviance in the dark’ placed in a completely dark room and told they would never see each other - participants engaged in sexual rather than violent behaviour

• practical applications in understanding aggressive behaviour in the online world - anonymity through digital handles rather than identifying information

• Social identity theory - deindividuation does not guarantee violence, rather shifts the individuals identity away from themselves and towards the group - if the group norms are antisocial, then this can lead to violence

what are the dispositional and situational explanations for institutional aggression (in the context of prisons)

• dispositional - importation model

• situational - deprivation model

outline Irwin and Cressey’s importation model of institutional aggression

• prisons are not completely isolated from what’s happening in the ‘real world’

  • prisoners come from the real world and bring with them, a subculture of criminality

• the willingness of inmates to use violence inside prison to settle disputes reflects their lives before they were imprisoned

• aggression = power, status, influence, and access

• aggression is the product of individual characteristics of inmates - not of the prison environment

• supported by DeLisi (2011)

Outline the procedure and findings of DeLisi’s (2011) research

• studied 813 juvenile delinquents confined in institutions in California

• the inmates all brought into confinement several negative dispositional traits

  • experiences of childhood trauma

  • substance abuse

  • a history of violent behaviour

• these inmates were more likely to engage in suicidal activity and sexual misconduct and committed more acts of physical violence compared to a control group

give a strength and a weakness of the importation model

• research support - 561 male inmates with similar criminal histories - ½ placed in high security prisons and ½ in low security

  • 33% of those in low and 36% of those in high were involved in aggression

  • no real effect of environment but similarity of inmates was a reliable predictor of aggression

• Dilulio offers an alternative explanation - the administrative control model the importation model ignores the role of prison officials. ACM states that aggression in prisons is caused by poor management, not disposition

outline Clemmer’s deprivation model of institutional aggression

• harsh conditions in prisons are stressful for inmates

  • they cope with this by resorting to aggressive and often violent behaviour

  • deprivation of material goods is especially important - creates competition between inmates to acquire them

• influence by the nature of the prison regime

• unpredictable routines can create frustration and use of ‘lock ups’ as punishment can remove other forms of stimulation leaving aggression as a more appealing option

• violence becomes an adaptive response to the problem of deprivation

• supported by Steiner’s research

outline procedure and findings of Steiner’s research

• investigated factors predicting inmate aggression in 512 prisons in the United States

• found that inmate on inmate violence was more common in prisons with higher proportions of female staff, inmates in protective custody etc …

• these are all prison level factors (independent of the individual characteristics of prisoners)

give a strength and a weakness of the deprivation model of institutional aggression

• contradictory research - prisons that allow conjugal visits do not display lower levels of aggression

• Cunnigham - out of 35 inmate homicides in Texas, all had motivations in some kind of deprivation

outline Bartholow and Anderson’s research into computer games and aggression

• participants played either an aggressive or non-aggressive computer game and then delivered white noise blasts at chosen volumes to punish a (non-existent) opponent

• those who played the violent video game selected significantly higher volumes of white noise

Outline DeLisi’s study into computer games and aggression

interviewed young offenders and found their level of violence to be highly correlated with the amount of time they spent playing violent video games

Outline Anderson’s study into computer games and aggression

• meta analysis - 136 studies

• +ve correlation between time spent playing violent video games and aggressive behaviour

give two weaknesses of research into the effects of computer games on aggression

• file drawer phenomenon - especially problematic for meta-analyses as they only deal w published research

• non-equivalence problem - it is difficult, in studies comparing the effects of violent vs non violent video games to find games that are, apart from their levels of violence, equivalent. Violent games often require more activity from the user and things like the use of more keys.

list the three media influences on aggression

• desensitisation

• disinhibition

• cognitive priming

outline how media can cause desensitisation

• repeated exposure to violent material = habituation to its typical effects (activation of sympathetic NS)

• repeated exposure to violent material = belief that aggression as a method of solving conflict is socially acceptable

• Earls (1995) - showed male participants a film that has a prolonged and graphic scene of rape - and then a re-enactment of a rape trial.

  • compared with those who watched non sexually violent films, these participants showed less sympathy towards the victim in the trial and were less likely to believe the defendant to be guilty

outline how media can cause disinhibititon

• social constraints against aggressive behaviours can be weakened by repeated exposure to violent media

• the behaviour then appears more socially acceptable to the individual and is therefore more likely to occur

• link to SLT here

  • it is not unusual for video games to show violent behaviour being rewarded

outline how media can cause cognitive priming

• consuming violent media can provide us with a ready made script for how violent situations can play out

• this script is stored in our memory and so we become ready or ‘primed’ to be aggressive

  • mostly an automatic process - can direct our behaviour without us even being aware of it

  • can then be triggered when we encounter a situation we perceive to be aggressive.

• study into cognitive priming

  • male participants who listened to songs with aggressively derogatory lyrics about women recalled more negative qualities about women and behaved more aggressively towards a female confederate

give a strength and a weakness for explanations of media influences on aggression

• practical application - understanding of priming through cognitive scripts could lead to the ability to challenge hostile cognitive bases - decreasing likelihood of harmful aggressive acts

• alternative explanation for aggression - catharsis - some believe aggression reduces further violence by ‘getting it out of your system’