Aggression: Nature or Nurture? (Edexcel A-Level Psychology): Revision Notes
Aggression: Nature or Nurture?
Introduction
The question of whether aggression stems from biological factors (nature) or environmental influences (nurture) has substantial implications for how society responds to violent behaviour. If aggression is primarily caused by biological factors beyond an individual's control, this raises important questions about criminal responsibility, appropriate responses to aggressive acts, and the possibility of predicting or preventing violent behaviour before it occurs.
Understanding the biological basis of aggression has far-reaching consequences for legal systems, treatment approaches, and how we conceptualize personal responsibility for violent actions.
Real-world context: Aggression in professional sport
Real-World Examples: Aggressive Incidents in Professional Football
Several high-profile incidents in professional football illustrate impulsive aggressive behaviour occurring under pressure:
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Luis Suárez (2014): Received a four-month ban after biting an opposing player during a World Cup match between Italy and Uruguay. This was the third such incident in his career, suggesting a pattern of impulsive aggressive reactions.
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David Beckham (1998): Sent off after kicking out at an opponent during a World Cup match, demonstrating impulsive aggression under high-stakes conditions.
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Zinedine Zidane (2006): Received a red card in the World Cup Final after headbutting an Italian player, an uncharacteristic outburst during extreme pressure.
Common Features:
- Occurred during high-stakes matches
- Happened on impulse rather than being premeditated
- Involved players who do not typically display such behaviour
These incidents raise an important question: Footballers are trained to think and react quickly on the pitch, developing strong impulsive tendencies that serve them well professionally. However, this same impulsivity can manifest as aggression when placed in the wrong situation or under extreme pressure.
Biological explanations for aggression
Impulsivity and the prefrontal cortex
Impulsivity represents an evolutionary adaptation that allows organisms to respond quickly to threats and opportunities. As humans evolved to live in large social groups, self-restraint developed as a complementary mechanism to prevent impulsive actions from damaging social relationships. The prefrontal cortex is the brain region responsible for controlling impulses, acting as a brake on immediate reactions.
Evolutionary Context
Impulsivity is a survival mechanism, useful as an ability to think and act quickly and avoid threats. However, in modern social contexts, uncontrolled impulsivity can lead to behaviour that damages relationships and social standing.
Research by Raine et al. (1997) provided evidence linking violent behaviour to brain function. The study found that violent behaviour (in this case, murder) was related to low levels of activity in the prefrontal cortex, suggesting violence is caused by poor impulse control. This biological mechanism helps explain why some individuals struggle to restrain aggressive impulses.
High-Pressure Situations and Impulse Control
Impulse control can be compromised by situational factors. High-pressure situations, such as major sporting events, create stress that may interfere with the prefrontal cortex's normal function. When the ability to control impulses is hindered, even individuals who typically manage their behaviour well may experience aggressive outbursts.
This explains why footballers like Beckham, despite normally channelling impulsive tendencies productively, can lose control under extreme match pressure.
Psychologists argue that impulsivity is a behavioural trait that people learn to manage through experience in different social contexts. The World Cup represents an unusually high-pressure environment where the normal ability to regulate impulses becomes impaired, potentially triggering aggressive behaviour even in well-adjusted individuals.
Hormonal influences: Testosterone
Testosterone is a hormone linked to several behavioural characteristics, including dominance, competitiveness and aggression. High testosterone levels may increase the likelihood of aggressive behaviour. The real-world examples discussed all involve male athletes, and the same hormone that drives their competitive success in sport may also increase their propensity for aggression.
This hormonal explanation provides a biological basis for why individuals in competitive environments might be more prone to aggressive outbursts. The testosterone that contributes to athletic performance and competitive drive may simultaneously lower the threshold for aggressive responses to perceived threats or provocations.
Genetic factors: The MAOA gene
The MAOA gene, often called the 'warrior gene', has been linked to aggressive and impulsive behaviour. Individuals with a variant of this gene showing low activity or low expression may be more likely to react to provocation with aggression. Research by McDermott et al. (2009) found evidence supporting this connection between MAOA gene variants and aggressive responses.
Interaction Effects
Additional research has shown that people with low expression variants of the MAOA gene who also have high testosterone levels are particularly likely to display aggression, especially if they experienced difficult childhoods. This demonstrates how genetic factors can interact with both hormonal influences and environmental experiences to shape behaviour.
The genetic explanation suggests that some individuals may have a biological predisposition toward aggression that makes controlling such impulses more difficult, regardless of their conscious intentions or efforts.
Implications for society
Criminal responsibility and punishment
If aggression has biological causes, this creates complex questions about holding individuals accountable for violent actions. The key issue is whether people who display aggression due to biological factors can be held criminally responsible for their behaviour. In the case of Luis Suárez, for example, if his aggressive outbursts result from biological features beyond his control, should he receive the same punishment as someone who acts aggressively through conscious choice?
Alternative Perspective: Biology as Adaptation
Some argue that biological factors that make aggression more likely represent positive adaptations in certain contexts. The impulsivity that makes footballers successful could be viewed as an asset rather than a defect. If someone's biology predisposes them to occasional aggressive outbursts but otherwise contributes positively (such as successful athletic careers), harsh punishment may be inappropriate.
However, the fact that someone has a biological tendency toward impulsive behaviour does not necessarily mean they should be treated more leniently when aggression occurs.
Treatment versus punishment approaches
The biological perspective on aggression suggests that violent individuals may require help rather than punishment. If a person's biology causes their aggressive behaviour, punishing them could be seen as unfair since the behaviour stems from factors beyond their conscious control. This biological understanding might change how society views aggressive behaviour, potentially reframing it as a form of illness or disorder symptom rather than a moral failing.
Understanding the biological basis of aggression opens possibilities for different societal responses. Rather than focusing solely on punishment, resources could be directed toward helping individuals manage biological predispositions toward aggression. This could include developing treatments or interventions that address the underlying biological factors.
Prediction and prevention
If biological factors cause aggression, this raises the possibility of identifying at-risk individuals before they display violent behaviour. Understanding which biological predispositions correlate with aggression could enable development of mechanisms to predict aggressive behaviour in certain people. Society could then focus on preventing violent acts before they occur through targeted interventions.
This predictive capability could involve assessing factors such as prefrontal cortex function, testosterone levels, or MAOA gene variants to identify individuals who may struggle with impulse control or have heightened aggression risk. Early identification could allow for preventive measures, potentially reducing violent incidents.
Ethical Concerns
This approach raises ethical concerns about labelling individuals as potentially aggressive based on biological markers, particularly before any violent behaviour has occurred. The question of whether society should identify and monitor people based on biological predispositions remains highly controversial.
Wider issues: Free will versus determinism
The biological explanation for aggression engages with the fundamental philosophical question of free will versus determinism. Biological determinism suggests that behaviour is predetermined by biological factors present in an individual. If aggression results from brain function, hormone levels, or genetic makeup, this implies that aggressive individuals cannot control their behaviour—it is simply the result of how their biology functions.
The Deterministic View
This deterministic view removes the element of free will from aggressive behaviour. It suggests that individuals cannot be held fully responsible for their actions because they result from biological factors beyond personal control. Taking blame away from individuals for aggressive actions implies they cannot help behaving as they do.
Limitations of Biological Determinism
However, this perspective fails to explain why not all people with biological features associated with aggression become aggressive, or why some people display aggression without any apparent biological predisposition. If biology completely determined behaviour, we would expect consistent patterns that do not always emerge in reality.
This suggests that whilst biological factors may increase vulnerability to aggression, they do not entirely remove individual agency or environmental influences.
The free will versus determinism debate has practical implications for justice systems and social policy. If aggression is biologically determined, traditional notions of criminal responsibility may need revision. Conversely, if some degree of free will exists despite biological predispositions, individuals retain responsibility for managing their behaviour even when biology makes this more challenging.
Remember!
Key Points to Remember:
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Biological factors linked to aggression include impulsivity controlled by the prefrontal cortex, testosterone levels, and variants of the MAOA gene.
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Raine et al. (1997) found that violent individuals showed lower prefrontal cortex activity, suggesting poor impulse control contributes to aggression.
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Testosterone and the MAOA 'warrior gene' provide hormonal and genetic explanations for why some individuals may be more prone to aggressive behaviour.
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If aggression stems from biological causes, this raises questions about criminal responsibility, whether punishment is appropriate, and whether aggressive individuals should receive treatment rather than punishment.
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The free will versus determinism debate becomes central—if biology causes aggression, individuals may lack control over their actions, but this fails to explain why not everyone with risk factors becomes aggressive.