Aggression

What are the neural mechanisms of aggression?

* limbic system
* serotonin

What is a neural mechanism?

* have an influence solely on your brain

What is the hormonal mechanism of aggression?

* testosterone

What is a hormonal mechanism?

* created in glands in the brain or body

What is the limbic system?

* series of areas in the brain that help to regulate emotions

What areas of the brain does the limbic system involve?

* hypothalamus
* hippocampus
* amygdala
* thalamus

What does the amygdala do?

* evaluates the emotional importance + providing an appropriate resource

What effect does a more responsive amygdala have on aggression?

* more likely a person will show aggressive behaviour

What does the hippocampus do?

* involved in the formation of long term memory
* allows you to compare your past experiences of a threat with current situations to help decide the appropriate behaviour to display

What was the procedure of Gospic et al (2011) ultimatum game as support for the limbic system?

* participants asked to take money someone had split with them or leave it

\- sometimes given unfair splits

What were the findings of Gospic et al (2011) ultimatum game?

* when rejected unfair offers amygdala were highly active
* participants given benzodiazepine (reduces hippocampus arousal) before task it halved number of rejections + decreased amygdala activity

\- (shows involvement of limbic system in aggression)

What is serotonin?

* neurotransmitter involved in passing messages across the brain

What is the effect of serotonin on aggression?

* inhibits neural activity
* normal levels of serotonin in orbitofrontal cortex linked with reduced firing of neurons + increased self control

\- decreased levels lead to reduced levels of self control + increased levels of impulsive behaviour

What is testosterone?

* male sex hormone
* development of masculine features

\- facial hair, body hair + broad shoulders

What is the effect of testosterone on aggression?

* role in regulating social behaviour (supported by animal studies on multiple species) having impact on aggression
* positive correlation found between testosterone levels of criminals + aggressive behaviour

What are genetic factors?

* genes consist of DNA that decide physical traits, neurotransmitter levels + size of brain

→ influence psychological features (intelligence or mental health)

What are the three ways psychologists study the influence of genetics on aggression?

* twin studies
* adoption studies
* MAOA gene

What does twin studies suggest about aggression?

* might be inherited
* genes count for 50% variance in aggressive behaviour

What does variance mean?

* how much genes play a role in behaviour

What did Coccaro et al (1997) found for the concordance rates of physical and verbal aggression?

* found 50% concordance rate for MZ twins + 19% for DZ twins for physical aggression
* 28% + 7% for verbal aggression

What is a concordance rate?

* percent of cases in which both members of a pair have a particular attribute

Why are adoption studies used to study the influence of genetic factors?

* to separate out the genetic influence + environmental influence

What was Rhee and Waldman (2002)’s adoption study for aggression and genetic influence?

* meta analysis of adoption studies of direct aggression + antisocial behaviour

What did Rhee and Waldman (2002)’s adoption study for aggression and genetic influence find?

* found genetic influences account for 41% of variance in aggression

→ (support for genetic explanation)

What is meta analysis?

* process where researchers collect + collate a wide range of previously conducted research on a specific area

What is MAOA?

* (Monoamine Oxidase A)


* enzyme that absorbs any neurotransmitter in synaptic gaps that are not absorbed by post synaptic neuron

\- particularly serotonin

What can dysfunction in the MAOA area lead to?

* lead to abnormal activity of enzyme → affecting behaviour

What is the MAOA gene variant?

* “warrior gene”
* lead to low MAOA activity in brain + associated with high levels of aggression

What is the diathesis stress model?

* have genetic predisposition to something but will only develop traits triggered by traumatic life event / series of them

What did Frazzetto et al (2007) find when aggression was linked with early traumatic life events?

* link between higher levels of aggression + low activity of MAOA gene but only when severe trauma was experience in first 15 years of life

\- (support for diathesis stress model)

What are the two evolutionary explanations of aggression?

* ethology
* sexual jealousy

What is ethology?

* study of animal behaviour in natural settings

Who is the founder of ethology?

* Lorenz (1966)

What does Darwin suggested about ethology and aggression?

* ethologists suggested aggression can be studied in animals + be applied to humans because all subject to same forces of nature

What are the three ethological explanations for aggression?

* evolutionary adaptive functions of aggression
* ritualistic aggression
* innate releasing mechanism (IRM) + fixed action potential (FAP)

What are the evolutionary adaptive functions of aggression?

* animals of same species don’t kill each other in fights as don’t want to reduce number of species
* when one loses they leave area + spread out over wider area so dominate more land
* beneficial to survival as aggression establishes a hierarchy
* dominance gives them special privileges such as mating with females

What did Pettit et al (1988) find about the evolutionary adaptive functions of aggression in humans?

* children who showed aggressive behaviour towards peers have power over others + able to get own way

What is ritualistic aggression?

* show displays of aggression instead of fighting
* helpful to show strength + deescalates fights (physically costly + dangerous)
* threats make others back down from fight

What is an example of ritualistic aggression in humans as found by Gardner and Heider (1968)?

* Dani of New Guinea show ritualistic aggression through banging spears on ground + calling tones made

What are innate releasing mechanisms (IRMs)?

* hard wired brain networks that respond to specific stimuli (signs + releasers) by initiating a fixed action patter

What is a fixed action pattern (FAP)?

* adaptive sequence or stereotyped / ritual behavioural

\- (set sequence of behaviours)

What are the six features of FAPs?

* stereotyped / relatively unchanging sequences of behaviour
* universal
* unaffected by learning
* “ballistic”
* single purpose (only specific situation)
* response to specific sign

What does universal mean in terms of FAPs?

* found in all species

What does ballistic mean in terms of FAPs?

* once behaviour triggered it always follows same sequence

How is IRMs and FAPs shown in stickleback fish?

* stickleback fish develop red belly when looking for mate

\- indicates maturity for mating
* red belly = IRM as universal to the fish + stereotyped as will always lead to same behaviour when other fish see it
* FAP is another fish wanting to fight for territory + potential mates

\- behaviour = ballistic as always same sequence of fighting

What are the survival benefits of aggression?

* effective strategy for solving several adaptive problems among early humans

\- example → cheating + males trying to become group leader
* solving problems enhanced survival + reproductive success of individual

Why is sexual jealousy a major motivator for aggressive behaviour in males?

* males could never be sure they truly fathered the child they were supposed to be looking after + protecting

\- called cuckoldry

Why is sexual jealousy adaptive?

* would deter a mate from sexual infidelity → minimising risk of cuckoldry

What are the three mate retention strategies?

* violence towards partner or potential love rivals (Buss, 1988)
* direct guarding (Wilson and Daly, 1996)


* negative inducements (Wilson and Daly, 1996)

What is violence towards partner or potential love rivals?

* physically showing aggression towards partner or someone they believe to be giving affection towards / receiving from

What is direct guarding?

* involves male vigilance over a partners behaviour

\- examples → checking who seeing, keep tabs on whereabouts (apps)

What are negative inducements?

* threats, such as issuing threats of dire consequences for infidelity

\- example → “I will kill myself if you leave”

What is an example of a statement that was included in Wilson et al (2005)’s mate retention study?

* “he insists on knowing who you are with + where you are at, at all times”

What were the findings of Wilson et al (2005)’s mate retention study?

* found women who reported mate retention strategies in partners were twice as likely to suffer from physical violence from partner

\- 73% required medical attention

\- 53% feared for lives

What is the conclusion of Wilson et al (2005)’s mate retention study?

* sexual jealously can cause direct guarding which leads to physically aggressive behaviour towards partner

What are the limitations of Wilson et al (2005)’s mate retention study?

* only asked closed questions so can’t gain full understanding of behaviour causes
* gender bias → not recognising female abusers + male victims
* methodological problems → different levels of fear (hard to measure)

What was the procedure of Shackleford et al (2005)’s intimate partner violence study?

* 107 recently married couples (within last year) completed two questionnaires
* men completed mate retention inventory
* women completed spouse influence report which measure extent of partners violence

What were the findings of Shackleford et al (2005)’s intimate partner violence study?

* strong positive correlation between men’s report of mate retention behaviours + women’s report of partners physical violence

What is the problem with the correlational data of Shackleford et al (2005)’s intimate partner violence study?

* does not show causation therefore cannot be sure males sexual jealousy feelings cause their aggressive behaviour

How reliable are the results of Shackleford et al (2005)’s intimate partner violence study?

* may be reliable as questionnaires are well established + likely to provide same results if repeated

What are the three social-psychological explanations for aggression?

* frustration aggression hypothesis
* social learning theory
* deindividuation

What is Dollard et al (1939)‘s frustration aggression hypothesis?

* suggests aggression is result of frustration from not being able to achieve goals
* cause + effect relationship between frustration, aggression + catharsis
* become frustrated → active aggressive (unconscious) drive → aggressive urges
* frustration lead to motivation to achieve aggressive goal + succumb to urge results in catharsis

What is catharsis in terms of aggression?

* emotional release achieved by person engaging in aggressive behaviour / having aggressive thoughts

What are the three reasons frustration is not directly against the cause of frustration?

* cause of frustration is abstract
* cause may be too powerful + risk punishment by aggressing against it
* cause may be unavailable at time

What is an example of the cause of frustration being abstract?

* economy or government

\- not tangible

What is an example of the cause of frustration being too powerful and risk punishment by aggressing against it?

* teacher who gave you low grade or police who gave you parking ticket

\- risky behaviour

What is an example of the cause of frustration being unavailable at the time?

* teacher left before you realise you got a bad grade

What was the procedure for Green (1968)’s study to support the frustration aggression hypothesis?

* male university students given jigsaw to complete
* three conditions → impossible puzzle, interrupting confederate so ran out of time + confederate insulting participants inability
* then asked to give electric shock to confederate when they made a mistake on another task

What were the results for Green (1968)’s study to support the frustration aggression hypothesis?

* insulted participants gave strongest shocks followed by interfered
* all three groups selected more intense shocks than non frustrated control group

What is observational learning in terms of aggression?

* learn behaviour through others
* children observe aggressive role model behaviour (parents / peers)

\- (indirect)

How is social learning theory applied to aggression?

* child pay attention to outcome of role model behaviour
* motivation to imitate behaviour comes from seeing behaviour rewarded (vicarious reinforcement) allows child to learn aggressive behaviour gets them desired outcome
* behaviour only repeated if it can be reproduced involving child mentally appraising they can do it
* have ability to keep memory of behaviour so can be applied to future scenario (retention)

What is self efficacy?

* extent to which we believe our actions will achieve a desired goal

How does self efficacy in SLT link to aggression?

* child will feel more confident executing aggressive act if they know it can lead to rewards

\- (child hit sibling regularly for toy → learns has motor skills needed → keep repeating behaviour)

What was the procedure of Bandura’s (1961) bobo doll experiment?

* children asked to observe an adult role model either being aggressive or non aggressive behaviour towards bobo doll

\- kicking, hitting with hammer + shouting
* children then taken to new room + given variety of toys to play with + researchers observed behaviour

What were the findings of Bandura’s (1961) bobo doll experiment?

* children copied both verbal + physical actions of role models

\- some directly copied


* was copied regardless of role model gender
* non aggressive group showed almost no aggressive behaviour

What is deindividuation?

* when membership of co acting group/crowd leads to reduction in feeling of personal responsibility
* a psychological state we take on

How does deindividuation lead to aggression?

* when monogamous (in crowd) makes us feel unaccountable for behaviour

\- increases chances of carrying out prohibited behaviour
* larger the group the greater the feeling of anonymity

\- there is decreased fear people will judge us individually as someone negatively → feel less guilty
* identities believed to be unknown more likely to act aggressively

What did Prentice-Dunn and Rodgers (1982) add to the original deindividuation theory?

* deindividuation is mediated by self awareness

What are the two types of self awareness?

* private self awareness
* public self awareness

What is private self awareness?

* how we pay attention to our own thoughts + feelings

How does private self awareness work?

* pay less attention when part of a crowd instead focus outwardly on events occurring around us
* means less critical of own behaviours + less thoughtful leading to deindividuated state
* example → focus on those at protest + what they’re doing instead of on feelings of personal safety

What is public self awareness?

* appraisal of other people

\- (how much we care about what others think of us)

How does public self awareness work?

* larger the crowd the more a person feels they are not being judged for own actions but instead actions of group
* diffusion of responsibility + feel less accountable for aggressive behaviour
* example → friends picking on another kid, forgetting equally responsible for group even though only watched

What was the procedure of Dodd’s (1985) deindividuation research?

* asked 229 undergraduate psychology students to answer question

\- “if you could do anything humanly possible with complete assurance that you would not be detected or held responsible, what would you do?”
* students aware responses were completely anonymous

What were the findings of Dodd’s (1985) deindividuation research?

* 36% responses → some form of antisocial behaviour
* 26% responses → criminal acts
* 9% responses → prosocial behaviour

What was the conclusion of Dodd’s (1985) deindividuation research?

* deindividuation can cause people to act in both pro social + anti social manner when they feel anonymous

What is institutional aggression?

* how prisons cultivate aggressive + violent behaviour

What are the two theories that may explain aggressive behaviour in prisons?

* importation model (dispositional factors)
* deprivation model (situational factors)

What are dispositional factors?

* any explanation of behaviour which accounts for personality

Who proposed the importation model?

* Irwin and Cressey (1962)

What are the characteristics of the importation model?

* individuals bring characteristics + traits from outside into prison
* come from environment where violence + aggression is norm this will prevail in prison environment
* gang membership pre prison shown to be key predictor of prison misconduct
* low self control was significant predictor of aggressive behaviour both in + before prison

What are the three subcultures as part of the importation model?

* convict subculture
* conventional subculture
* criminal “thief” subculture

What is the convict subculture?

* most likely to show aggression
* seek positions of power + influence within institution + use aggression to do this

What is the conventional subculture?

* comprised of one time offenders who reject other subcultures within prison + identify more with staff

What is the criminal “thief” subculture?

* follows norms inherited by those in criminal profession
* are trustworthy / loyal to other criminals but not aggressive

What are situational factors?

* any explanations of behaviour that consider environment

Who proposed the deprivation model?

* Sykes (1958)

What are the characteristics of the deprivation model?

* prison environment affect person’s level of aggression
* prisions “deprive” people’s freedom causes severe stress leading to aggressive acts to feel some control in lives

\- example → autonomy, security, personal space


* also deprived of heterosexual relationships can often lead to aggressive acts of homosexual + non consensual sex

What are some circumstances that make prisoners violent according to Cooke et al (2008)?

* overcrowding
* heat + noise
* job burnout

How does overcrowding increase aggression?

* 2014 government report found rates of murder, suicide + assaults in prison correlated with prison population density