Aggression is a pervasive and complex behaviour that has attracted substantial theoretical debate within psychology. This essay will evaluate two prominent psychological explanations: the biological perspective, which emphasises innate mechanisms such as serotonin and testosterone, and the social learning theory (SLT) proposed by Bandura (1973, 1977), which stresses observational learning and environmental reinforcement. Each perspective will be critically assessed in terms of its empirical support, explanatory power, limitations, and implications for understanding real-world aggression. The essay will conclude that while biological accounts offer valuable insights into predisposing factors, SLT provides a more comprehensive framework for explaining the acquisition and maintenance of aggressive behaviour, particularly in social contexts.
The Biological Explanation of Aggression
The biological perspective asserts that aggression is largely determined by genetic, neural, and hormonal factors. For example, low levels of the neurotransmitter serotonin have been consistently linked to increased impulsivity and aggression. Research by Mann et al. (1994) demonstrated that depleting serotonin in healthy volunteers led to higher ratings of hostility and aggression. Similarly, the hormone testosterone has been associated with dominant and aggressive behaviour. Dabbs et al. (1995) found that male prisoners with higher testosterone levels were more likely to have committed violent crimes. Furthermore, genetic studies using twin designs report heritability estimates for aggression ranging from 40% to 50% (Miles & Carey, 1997), suggesting a moderate genetic influence.
Evaluation of the biological explanation
A key strength of the biological approach is its use of objective, scientific methods. Brain imaging and biochemical assays allow precise measurement, lending internal validity to findings. For instance, Raine et al. (1997) used PET scans to reveal reduced prefrontal cortex activity in murderers, a region involved in impulse control. Such evidence provides a plausible neurobiological substrate for aggression.
However, the biological perspective has been criticised for being reductionist. By explaining aggression solely in terms of neurotransmitters or genes, it overlooks the crucial role of social context and learning. For example, not all individuals with high testosterone become aggressive; cultural norms and situational factors moderate this relationship (Archer, 1991). Moreover, the direction of causality is unclear — does high testosterone cause aggression, or does aggressive behaviour increase testosterone levels? This bidirectional relationship weakens the explanatory power of biological accounts.
Another limitation is the difficulty in applying biological findings to real-world interventions. While drug treatments (e.g., SSRIs) may reduce aggression in some clinical populations, they do not address the environmental triggers or learned patterns that often maintain aggressive conduct. Therefore, while biological factors certainly contribute, they cannot provide a complete explanation.
Social Learning Theory (SLT) Explanation of Aggression
In contrast, Bandura’s (1973) social learning theory emphasises the role of observation, imitation, and reinforcement in the acquisition of aggressive behaviour. The classic Bobo doll experiment (Bandura, Ross & Ross, 1961) demonstrated that children who watched an adult model act aggressively towards a doll were significantly more likely to imitate that behaviour than those who saw a non-aggressive model. Bandura argued that aggression is learned through modelling, either directly (e.g., seeing a parent hit) or vicariously (e.g., watching violent media). The behaviour is then maintained through direct reinforcement (e.g., gaining status) or vicarious reinforcement (seeing the model rewarded).
Evaluation of SLT
The SLT approach has strong empirical support from controlled laboratory experiments. The Bobo doll studies have been replicated many times, confirming that children readily acquire aggressive responses through observation. This research has high internal validity and demonstrates a clear causal relationship between exposure to aggressive models and subsequent aggressive behaviour. Moreover, SLT accounts for individual differences: not all observers imitate; factors such as identification with the model, perceived similarity, and the consequences of the model’s actions moderate learning (Bandura, 1977).
A major strength of SLT is its practical relevance. It has been used to inform interventions such as media literacy programmes and parenting strategies that reduce children’s exposure to violent role models. It also explains why aggression can vary so dramatically across cultures and historical periods — because social norms and available models differ.
Nevertheless, SLT has been criticised for underestimating biological factors. Not all children who observe aggression become aggressive; some show no change, suggesting a genetic vulnerability or differential susceptibility. Furthermore, the Bobo doll experiments involved a very specific, artificial setting; critics argue that aggression towards an inflatable doll may not generalise to real interpersonal violence. The doll was designed to be hit, and children may have been responding to the novelty or playfulness of the situation rather than learning aggression per se.
Additionally, SLT struggles to explain spontaneous or unlearned aggression that occurs without prior observation, such as reflexive aggression in infancy. This suggests that some aggressive tendencies are innate, which the biological perspective captures better.
Comparisons and Synthesis
When comparing the two perspectives, it becomes clear that neither can fully account for the complexity of aggression. The biological explanation excels at identifying predisposing factors, such as low serotonin or high testosterone, that increase the likelihood of aggression. However, it fails to explain why rates of aggression differ so markedly between societies or why particular individuals become aggressive only in specific situations.
SLT, by contrast, explains the acquisition of aggressive patterns through environmental learning and accounts for cultural variation. Yet it neglects the biological underpinnings that may moderate the learning process. A more complete understanding requires an interactionist approach. For example, the diathesis-stress model suggests that biological vulnerabilities (e.g., low MAO-A activity, Caspi et al., 2002) interact with environmental triggers (e.g., childhood maltreatment) to produce aggression. This integrated view is increasingly supported by research (Rhee & Waldman, 2002).
Furthermore, contemporary cognitive approaches (see Evaluate the Contribution of the Cognitive Approach to Our Understanding of Human Behaviour) also add value by focusing on how hostile attribution biases and scripted mental representations mediate the link between social learning and aggressive behaviour. This suggests that aggression is multiply determined and that no single perspective is sufficient.
Conclusion
In conclusion, the biological perspective provides robust evidence for innate contributions to aggression through neurochemical and genetic mechanisms, but it is reductionist and neglects learning and context. Social learning theory offers a well-supported account of how aggression is acquired through observation and reinforcement, yet it underestimates biological predispositions and may over-rely on artificial experiments. For A Level students preparing to write high-scoring essays on this topic, resources such as Mastering the 5-Paragraph Essay can help structure critical evaluations, while Writing Effective Essays: A Guide To College-Level Writing provides further guidance on academic style. Ultimately, the most convincing explanations of aggression are those that integrate biological, environmental, and cognitive factors, acknowledging that human behaviour emerges from the interplay of multiple systems. Future research should continue to explore gene–environment interactions to develop more effective prevention strategies.
Further Reading
For those seeking to improve their essay-writing skills for A Level Psychology, consider these helpful books:
References
Archer, J. (1991). The influence of testosterone on human aggression. British Journal of Psychology, 82(1), 1–28.
Bandura, A. (1973). Aggression: A social learning analysis. Prentice-Hall.
Bandura, A. (1977). Social learning theory. Prentice-Hall.
Bandura, A., Ross, D., & Ross, S. A. (1961). Transmission of aggression through imitation of aggressive models. Journal of Abnormal and Social Psychology, 63(3), 575–582.
Caspi, A., McClay, J., Moffitt, T. E., Mill, J., Martin, J., Craig, I. W., … & Poulton, R. (2002). Role of genotype in the cycle of violence in maltreated children. Science, 297(5582), 851–854.
Dabbs, J. M., Carr, T. S., Frady, R. L., & Riad, J. K. (1995). Testosterone, crime, and misbehavior among 692 male prison inmates. Personality and Individual Differences, 18(5), 627–633.
Mann, J. J., Waternaux, C., Haas, G. L., & Malone, K. M. (1994). Toward a clinical model of suicidal behavior in psychiatric patients. American Journal of Psychiatry, 151(1), 55–64.
Miles, D. R., & Carey, G. (1997). Genetic and environmental architecture of human aggression. Journal of Personality and Social Psychology, 72(1), 207–217.
Raine, A., Buchsbaum, M., & LaCasse, L. (1997). Brain abnormalities in murderers indicated by positron emission tomography. Biological Psychiatry, 42(6), 495–508.
Rhee, S. H., & Waldman, I. D. (2002). Genetic and environmental influences on antisocial behavior: A meta-analysis of twin and adoption studies. Psychological Bulletin, 128(3), 490–529.
Related A Level Psychology Topics
- Evaluate the Contribution of the Cognitive Approach to Our Understanding of Human Behaviour.
- Discuss the Extent to Which Behaviour Is Determined by Nature Rather Than Nurture.
- Evaluate Research into Conformity and Obedience and Consider Its Relevance to Contemporary Society.
- Discuss the Strengths and Limitations of Using Laboratory Experiments in Psychological Research.
- Evaluate the Biological Explanations of Schizophrenia.
- Discuss the Role of Attachment in Early Childhood Development and Later Relationships.
- Evaluate Cognitive–behavioural Therapy (Cbt) as a Treatment for Depression.
- Discuss the Ethical Issues Raised by Psychological Research into Social Influence.
- Discuss the Reliability of Eyewitness Testimony and Evaluate Factors That May Affect It.
Frequently Asked Questions
What are the main psychological perspectives on aggression covered in this essay?
This essay evaluates the biological perspective (focusing on serotonin, testosterone, and genetics) and social learning theory (emphasising observational learning and reinforcement). It also touches on the potential for an interactionist approach.
Why is social learning theory considered more comprehensive than biological explanations?
Social learning theory accounts for cultural variation and the acquisition of aggression through modelling and reinforcement, which biological theories often neglect. However, both have limitations and a combined view is recommended.
How can I write a high-scoring A Level Psychology essay like this?
Focus on clear structure: introduction, balanced evaluation of each theory (strengths and limitations), comparison, and conclusion with real references. Use resources such as Mastering the 5-Paragraph Essay to refine your technique.
What are the key studies for the biological explanation?
Key studies include Mann et al. (1994) on serotonin depletion, Dabbs et al. (1995) on testosterone in prisoners, and Raine et al. (1997) on prefrontal cortex activity in murderers.
What are the key studies for social learning theory?
The classic Bobo doll experiments by Bandura, Ross, and Ross (1961) are central. Bandura's 1973 and 1977 books also provide the theoretical framework.
