Essay Plans
Aggression
Paper 3 - Section D
,Neural and hormonal influences
Outline and evaluate neural and/or hormonal explanations of aggression (8) / (16)
(don’t need all points - tailor to what the question asks)
Outline: neural explanations - brain structures - amygdala (AO1)
● The structure of certain parts of the brain causes aggression
● Limbic System → brain area that helps coordinate behaviours that satisfy
motivational and emotional urges such as aggression
● Two key structures associated with aggression are the amygdala / hippocampus
● Amygdala → responsible for emotional responses, linked to aggression
● High activity levels (hyperactivity) in the amygdala may be linked to aggression
● Reduced amygdala volume is also associated with aggression
Strengths: evidence for the amygdala (AO3)
● LeDoux: lab rats - found stimulation of the amygdala = aggression
● Electrical stimulation of the amygdala produced fear and rage on lab rats
● Supports amygdala's role in aggressive behaviour (result of direct stimulation)
● BUT, Eager and Flynn found stimulation of the amygdala would increase or
decrease aggression, depending on the region stimulated
● BUT we can’t assume human behaviour comparable to animals (very complex)
Outline: neural explanations - prefrontal cortex (AO1)
● PFC controls outward signs of aggression
● It directly connects to the limbic system / regulates amygdala-driven emotion
● Suggestion that damage to / reduced activity (hypoactivity) in the PFC is linked to
aggressive behaviour as it results in loss of control, impulsivity, altered emotionality
Strengths: evidence for the PFC (AO3)
● Raine’s research supports the role of the PFC in regulation of aggressive behaviour
● He scanned brains 41 murders - found they had reduced activity in their PF
● Evidence uses brain scanning techniques - highly objective / replicable
● Results in scientific credibility of the research
● Empirical evidence impaired PFC functioning is linked to aggressive behaviour
Outline: neural explanations - neurotransmitters (AO1)
● Serotonin is an inhibitory NT that exerts a calming effect
● Typically inhibits amygdala activity
● Low levels of serotonin associated with increased impulsive behaviour / aggression
Strengths: evidence - Raleigh (AO3)
● Studied verent monkeys on high tryptophan diets (increase serotonin levels)
● Found they exhibited decreased levels of aggression
● Suggests aggression may be due to differences in serotonin levels
● Limitations of applying human behaviour to that in monkeys
● There are many aspects of aggression due to complexities of behaviour
● NT’s alone can’t account for all aggressive behaviour - have a role in explaining it
,Outline: hormonal explanations (AO1)
● Evidence shows men are more aggressive than women
● Testosterone (male sex hormone) has been linked to aggression
● Sapolsky identified 3 explanations for the relationship:
testosterone = aggression / aggression = ↑ testosterone / don’t affect each other
Strengths: evidence - Sapolsky (AO3)
● When mice castrated (removing T production) their aggressive behaviour
(measured in biting attacks) dropped significantly
● When injected with testosterone, the aggression levels began to increase
● Suggests a direct impact of the androgen testosterone on aggressive behaviour
● Evidence supporting testosterone causes aggression / affects behaviour
● (BUT levels don’t return to normal - suggest T may impact something else)
● Mice not the same as human - findings can’t be applied to human behaviour
Weakness: issues and debates of neural / hormonal explanations (AO3)
● Reductionist - ignores other factors that could cause aggression
● Methodological - correlation ≠ causation
● Animal - can't be generalised to humans / unethical
● Deterministic - suggest if we have abnormal brain structure (etc) = aggression, so
we have no control over our behaviour
● Therefore this explanation is not good enough to explain human aggression
, Genetic factors in aggression
Discuss genetic factors involved in aggressive behaviour, refer to the MAOA gene (16)
Para 1 → Outline: twin studies (AO1)
● Coccaro compared MZ / DZ twins on aggressive behaviour (direct physical assault)
● Concordance rates of 50% for MZ twins / 19% for DZ
● Suggests aggression has a genetic basis - more genetically similar to someone who
displays aggressive behaviour, more likely you are to also be aggressive
Para 2 → Outline: MAOA gene (AO1)
● Monoamine oxidase A (MAOA) regulates MAOA enzyme in the brain
● It breaks down NTs: serotonin, dopamine and noradrenaline
● MAOA removes excess amounts of NTs so neurons communicate more effectively
● NTs linked to mood and buildup can cause people to respond aggressively to stress
● Problems with MAOA gene may cause abnormally high levels of the NTs
● This may then cause an increase in aggressive behaviour
Para 3 → Strengths: evidence - Brummer (AO3)
● 28 male members of a Dutch family (history of violence)
● All had MAOA gene (aka warrior gene) + abnormal levels of MAOA in their brains
● Implies its involvement in aggressive behaviour - less MAOA enzyme is produced,
therefore leads to build up of the NTs
Para 4 → Weakness: difficulties in determining the role of genetics (AO3)
● More than one gene usually contributes to aggressive behaviour
● Many other non-genetic influences (e.g environment) for aggressive behaviour
● Evidence suggests there’s an interaction between genes (nature) and
environmental influences (nurture)
● Caspi suggests genetic vulnerability (MAOA-L gene) may lead to aggression under
certain environmental conditions (maltreated as a child)
● Suggests strong influence of the environment
Para 5 → Strengths: explains gender differences (AO3)
● MAOA gene research offers an explanation for uneven rates of violence in M and W
● Niehoff - consequence of differential genetic vulnerability M/W have to MAOA gene
● The MAOA gene is linked to the X chromosome (Women have 2 / men have one)
● Men more likely to be affected by the X linked gene inherited from their mothers
● Women inheriting the gene are generally unaffected - have second X chromosome
with ‘normal’ gene for MAOA that prevents expression of the abnormal version
● Could explain why men typically show more aggressive behaviour than women
Para 6 → Weakness: application - criminal justice system (determinism) (AO3)
● People may be discriminated against for having the genes
● Or some criminals use it as an excuse to receive reduced sentences.
● If genetics cause aggressive behaviour, identifying aggressive individuals is easy
● But, not everyone with MAOA-L displays aggressive behaviour - suggests we can
exert free will on our behaviour
Aggression
Paper 3 - Section D
,Neural and hormonal influences
Outline and evaluate neural and/or hormonal explanations of aggression (8) / (16)
(don’t need all points - tailor to what the question asks)
Outline: neural explanations - brain structures - amygdala (AO1)
● The structure of certain parts of the brain causes aggression
● Limbic System → brain area that helps coordinate behaviours that satisfy
motivational and emotional urges such as aggression
● Two key structures associated with aggression are the amygdala / hippocampus
● Amygdala → responsible for emotional responses, linked to aggression
● High activity levels (hyperactivity) in the amygdala may be linked to aggression
● Reduced amygdala volume is also associated with aggression
Strengths: evidence for the amygdala (AO3)
● LeDoux: lab rats - found stimulation of the amygdala = aggression
● Electrical stimulation of the amygdala produced fear and rage on lab rats
● Supports amygdala's role in aggressive behaviour (result of direct stimulation)
● BUT, Eager and Flynn found stimulation of the amygdala would increase or
decrease aggression, depending on the region stimulated
● BUT we can’t assume human behaviour comparable to animals (very complex)
Outline: neural explanations - prefrontal cortex (AO1)
● PFC controls outward signs of aggression
● It directly connects to the limbic system / regulates amygdala-driven emotion
● Suggestion that damage to / reduced activity (hypoactivity) in the PFC is linked to
aggressive behaviour as it results in loss of control, impulsivity, altered emotionality
Strengths: evidence for the PFC (AO3)
● Raine’s research supports the role of the PFC in regulation of aggressive behaviour
● He scanned brains 41 murders - found they had reduced activity in their PF
● Evidence uses brain scanning techniques - highly objective / replicable
● Results in scientific credibility of the research
● Empirical evidence impaired PFC functioning is linked to aggressive behaviour
Outline: neural explanations - neurotransmitters (AO1)
● Serotonin is an inhibitory NT that exerts a calming effect
● Typically inhibits amygdala activity
● Low levels of serotonin associated with increased impulsive behaviour / aggression
Strengths: evidence - Raleigh (AO3)
● Studied verent monkeys on high tryptophan diets (increase serotonin levels)
● Found they exhibited decreased levels of aggression
● Suggests aggression may be due to differences in serotonin levels
● Limitations of applying human behaviour to that in monkeys
● There are many aspects of aggression due to complexities of behaviour
● NT’s alone can’t account for all aggressive behaviour - have a role in explaining it
,Outline: hormonal explanations (AO1)
● Evidence shows men are more aggressive than women
● Testosterone (male sex hormone) has been linked to aggression
● Sapolsky identified 3 explanations for the relationship:
testosterone = aggression / aggression = ↑ testosterone / don’t affect each other
Strengths: evidence - Sapolsky (AO3)
● When mice castrated (removing T production) their aggressive behaviour
(measured in biting attacks) dropped significantly
● When injected with testosterone, the aggression levels began to increase
● Suggests a direct impact of the androgen testosterone on aggressive behaviour
● Evidence supporting testosterone causes aggression / affects behaviour
● (BUT levels don’t return to normal - suggest T may impact something else)
● Mice not the same as human - findings can’t be applied to human behaviour
Weakness: issues and debates of neural / hormonal explanations (AO3)
● Reductionist - ignores other factors that could cause aggression
● Methodological - correlation ≠ causation
● Animal - can't be generalised to humans / unethical
● Deterministic - suggest if we have abnormal brain structure (etc) = aggression, so
we have no control over our behaviour
● Therefore this explanation is not good enough to explain human aggression
, Genetic factors in aggression
Discuss genetic factors involved in aggressive behaviour, refer to the MAOA gene (16)
Para 1 → Outline: twin studies (AO1)
● Coccaro compared MZ / DZ twins on aggressive behaviour (direct physical assault)
● Concordance rates of 50% for MZ twins / 19% for DZ
● Suggests aggression has a genetic basis - more genetically similar to someone who
displays aggressive behaviour, more likely you are to also be aggressive
Para 2 → Outline: MAOA gene (AO1)
● Monoamine oxidase A (MAOA) regulates MAOA enzyme in the brain
● It breaks down NTs: serotonin, dopamine and noradrenaline
● MAOA removes excess amounts of NTs so neurons communicate more effectively
● NTs linked to mood and buildup can cause people to respond aggressively to stress
● Problems with MAOA gene may cause abnormally high levels of the NTs
● This may then cause an increase in aggressive behaviour
Para 3 → Strengths: evidence - Brummer (AO3)
● 28 male members of a Dutch family (history of violence)
● All had MAOA gene (aka warrior gene) + abnormal levels of MAOA in their brains
● Implies its involvement in aggressive behaviour - less MAOA enzyme is produced,
therefore leads to build up of the NTs
Para 4 → Weakness: difficulties in determining the role of genetics (AO3)
● More than one gene usually contributes to aggressive behaviour
● Many other non-genetic influences (e.g environment) for aggressive behaviour
● Evidence suggests there’s an interaction between genes (nature) and
environmental influences (nurture)
● Caspi suggests genetic vulnerability (MAOA-L gene) may lead to aggression under
certain environmental conditions (maltreated as a child)
● Suggests strong influence of the environment
Para 5 → Strengths: explains gender differences (AO3)
● MAOA gene research offers an explanation for uneven rates of violence in M and W
● Niehoff - consequence of differential genetic vulnerability M/W have to MAOA gene
● The MAOA gene is linked to the X chromosome (Women have 2 / men have one)
● Men more likely to be affected by the X linked gene inherited from their mothers
● Women inheriting the gene are generally unaffected - have second X chromosome
with ‘normal’ gene for MAOA that prevents expression of the abnormal version
● Could explain why men typically show more aggressive behaviour than women
Para 6 → Weakness: application - criminal justice system (determinism) (AO3)
● People may be discriminated against for having the genes
● Or some criminals use it as an excuse to receive reduced sentences.
● If genetics cause aggressive behaviour, identifying aggressive individuals is easy
● But, not everyone with MAOA-L displays aggressive behaviour - suggests we can
exert free will on our behaviour
