Aggression - spec

Define aggression

All behaviour that is intended to inflict physical or psychological harm on another individual who does not want to be treated so

Describe role of limbic system in aggression

network of structures buried deep in the brain, composed of hypothalamus, amygdala, prefrontal cortex and parts of hippocampus

linked to emotional responses such as aggression

amygdala responds to environmental stress - its reactivity is an important indicator of aggressive behaviour

Role of limbic system AO3

Matthews et al (2006) - computer games - used fMRIs to measure brain function following playing violent/non-violent games - violent games showed increased activity in amygdala - scientific, controlled lab exp

Phineas Gage - case study - damaged left frontal lobe - link between amygdala and prefrontal cortex severed = lost rationality

Describe role of serotonin in aggression

Neurotransmitters that has inhibitory effect so is calming - slows down neural activity - those with reduced serotonin may have reduced self-control, leading to impulse + therefore aggressive behaviour

Evaluate role of serotonin in aggression

Virkkunen and Linnoila (1992) - cerebral spinal fluid - found products of serotonin breakdown to be significantly lower in impulsive offenders, suggesting they had lower serotonin levels

Man et al - weight loss drug - ppts given medication for WL which also happened to reduce serotonin levels + found that male participants became more aggressive

Describe the role of testosterone in aggression

Males generally more aggressive than females so attention has focused on hormone testosterone which is naturally higher in males

Testosterone promotes status-seeking/social dominance motives which is linked to assertive/violent behaviour

Evaluate role of testosterone in aggression

Wagner et al - mice - when chemically castrated mice, they became docile + when increased testosterone they became more aggressive BUT issues with generalising from animals to humans (as humans may be more aggressive due to environmental stimuli)

outline genetic factors in aggression

Assume aggressive behaviour is the result of inherited traits/characteristics that have adapted across generations because of their evolutionary advantage

Describe the role of MAOA gene in aggression

Produces an enzyme with role to ‘mop up’ neurotransmitters in synapse after nerve impulse transmitted - breaks down serotonin + helps with its reuptake

Low levels of MAOA enzyme = lows levels of serotonin as less is reabsorbed into neurone leading to aggressive behaviour

Evaluate role of MAOA gene

Bruner et al (1993) - Dutch family of abnormally violent criminals - had abnormally low levels of MAOA gene

Frazzetto eg al (2007) - MAOA must have trauma - argued that the MAOA gene is only active when significant trauma is experienced during the first 15 years of life

Outline how concordance rates can be used in investigating psychological traits

MZ twins share 100% of DNA + provide control sample for each other, but can also be compared to DZ twins

Adoption studies are used to investigate genetic factors in aggression as they may highlight differences between biological + adoptive parents and their children - can isolate environment child lives in as cause for behaviour

Give a study into concordance rates in aggression

Rhee + Waldman (2002) - meta analysis of adoption studies - found genetic influences accounted for 41% of variance in aggression

Evaluate the biological explanation of aggression

+ve - practical applications to benefit society - eg, give antidepressants (SSRIs) to prisoners may reduce aggression

+ve - benefit to economy - if can identify people before they commit a violent crime, means less people in prison so less money needed from taxpayers

-ve - strongly on nature side of nature vs nurture debate - reduces complex behaviour to its simplest (anatomical/biochemical) form so is reductionist, ignores gene-environment interaction + exhibits biological determinism

-ve - contrasting approaches with evidence - SLT (behavioural/environment/learning from others/experience)

What is ethology?

The study of animal + human behaviour in terms of traits, characteristics and rituals which have adapted to be useful for survival

What does the evolutionary explanation suggest about aggression?

It is an evolutionary process designed to minimise conflict and spread resources around the group - ritualistic behaviours are designed to deter competition

Why is no actual harm done to each animal in aggression in animals?

Because death is damaging to the species survival, so threat (eg, baring teeth growling) is only implied

Define an innate releasing mechanism

A build in physiological process or structure triggered by a specific environmental stimulus

Define a fixed action pattern

A specific sequence of behaviours released by an innate releasing mechanisms

Give 4 features of a fixed action pattern

Universal (in every individual of a species), unaffected by learning, ballistic (once triggered it runs its course), single purpose

AO3 ethological explanation - points

+ve - research into IRMa and FAPs by Tinbergen (1951) - red fish

-ve - cannot account for cultural differences in aggression

-ve - cannot be used to generalise to human aggression

Why can’t the ethological explanation account for cultural differences in aggression?

If aggression is innate, should account for aggression in all cultures

BUT research found white South Americans were more aggressive when insulted than white North Americans - further supported by differing homicide rates in these 2 regions

Shows that aggression differs from one culture to next - theory lacks internal validity

Why can’t the ethological explanation be used to generalise to humans?

Much research is carried out on non-primates (eg, fish) and results cannot be extrapolated to humans

Humans are more complex + their aggression may be a result of wide socio-economic triggers (eg, poverty) which is not replicated in animals

SLT would argue aggression is learnt (we don’t have FAPs)

What does evolutionary explanation suggest?

Aggression is the result of sexual competition, and is an inbuilt tendency for violence that is part of our basic nature

What has research suggested about gender differences in types of jealousy and why might this be the case?

Males are more prone to sexual jealousy than females but females more concerned about emotional infidelity

Can be explained by paternity uncertainty - sexual jealousy may be adaptive in that it may ensure a male is able to protect his genetic line

Give the evolutionary advantage for males and females

Males - spreading genes via more offspring

Females - secure a mate with the best resource potential

What are the evolutionary disadvantages of infidelity and how do males prevent this from occurring?

Cuckoldry and diverting resources from own offspring

Mate guarding strategies - controlling, domestic violence, lavishing with lots of resources

AO3 evolutionary explanation - points

+ve - sexual vs emotional jealousy evidence - accounts for gender differences

-ve - assumption that women are not aggressive is deterministic - results in disapproval of aggression ny females

Outline a study on the physical effects of computer games on aggression

assigned adolescents to play either violent or no violent computer game for 30 mins - fMRI immediately after showed increased activity in the amygdala + decreased activity in prefrontal lobe in those who played violent games

amygdala stimulates emotions, prefrontal regulates self control

Outline the effects of computer games on aggression

Desensitisation - playing lots over time means decreased emotional and physiological (FoF) response

Player in computer games take more active role compared to passive TV

Game playing more directly rewarded for player (operant conditioning)

Outline a study on the behavioural effects of computer games on aggression

Anderson + Bushman (2001)

Meta analysis, found that short term exposure to video game violence was significantly correlated with temporary increases in aggression in all participants

AO3 computer games - points

-ve - uncertainty on effects of long-term exposure (most research on short term)

-ve - difficulty distinguishing between ‘violent’ and ‘non-violent’ games - frustration vs excitement

-ve - ethical implications - social sensitivity

Why is there uncertainty on the effects of long-term exposure to computer games on aggression?

Lots of research suggests potential short term negative effects BUT less research into effects of long term exposure

Some research suggests potential benefits, so widespread concern around computer game use may be misplaced

Further longitudinal research required - with large, more randomly selected samples to investigate further

Why is there difficulty distinguishing between ‘violent’ and ‘non-violent’ games?

Many studies use games across conditions that aren’t particularly different - what constitutes violence is debatable and unclear in these studies

Frustration and excitement - violence may not be sole factor leading to aggression

Why is studying effects of computer games a socially sensitive toptic?

Researchers must be aware of how their findings will be interpreted in the media as the issue of computer game consumption and aggression has been popular topic for decades - results must be published in ways which are impartial, objective + fair