Genetic Factors in Aggression (OCR A-Level Psychology): Revision Notes
15.1.2 Genetic Factors in Aggression
The genetic explanation of aggression argues that:
- Genes influence our level of aggression.
- Different gene alleles make people behave more or less aggressively.
Evaluation:
(1)
P: There is research support for the influence of genes on aggression from twin studies
E: Twin studies have found a higher concordance rate for criminal behaviour among monozygotic twins than dizygotic twins
E: This demonstrates that genetics play a role in influencing the likelihood of aggressive behaviour, as MZ twins share more genes than DZ twins, providing further support for the explanation
(2)
P: There is research support for the influence of genes on aggression from adoption studies
E: An adoption study found that children who displayed criminal behaviour were significantly more likely to have biological parents who also displayed criminal behaviour
E: Thus, this similarity between the adopted children and their biological parents, must be due to genetics
Genes involved in aggression:
MAOA gene: Produces a chemical that controls the number of neurotransmitters like serotonin available at the synapse.
- Short allele is linked to higher aggression
- Long allele is linked to lower aggression
Evaluation:
(1)
P: There is research support for the role of the MAOA gene in aggression
E: For example, Frazzetto et al found a correlation between low activity in the MOAO gene and higher levels of aggression in adult men.
E: This increases the validity of the explanation by providing real-life support.