Topic 3: Biological psychology — Edexcel A-Level Psychology
Test yourself on Topic 3: Biological psychology with PEARSON EDEXCEL A-Level practice questions.
7 days Premium · Then the free plan continues · No card, no charge
Topic 3: Biological psychology explained
This topic explains behaviour by what the body does, working from genes and evolved tendencies through hormones and neurotransmitters to the brain structures that start and restrain a violent act, and it uses aggression as the behaviour that ties them together.
Read the full explanation
Raine, Buchsbaum and LaCasse (1997) scanned murderers who had pleaded not guilty by reason of insanity and found reduced glucose metabolism in the prefrontal cortex together with asymmetries in the amygdala and other subcortical areas, while controls did not. Brunner and colleagues described a Dutch family in which men with a deficiency of the enzyme monoamine oxidase A showed impulsive aggression, and Brendgen and colleagues found physical aggression in twins more strongly genetically influenced than social aggression.
Individual differences and developmental psychology must be considered when learning about issues such as aggression caused by an accident and how the function of structures of the brain can be affected by the environment.
Biology does not act the same way in every person or at every age, and this strand asks you to say why. The individual differences point is made by cases of acquired damage: Phineas Gage survived an iron rod driven through the front of his brain in the nineteenth century and Harlow reported a change in his social conduct afterwards, while Damasio and colleagues later modelled the likely path of the rod through ventromedial prefrontal tissue and other researchers modelled the damage to connecting fibres. The developmental point is that the same structures are built under environmental influence: Caspi and colleagues found that low activity of the monoamine oxidase A gene predicted antisocial outcomes mainly in men who had been maltreated as children, so genotype and upbringing act together rather than separately.
Your focus
- Students must show an understanding that biological psychology is about the mechanisms within our body and understand how they affect our behaviour, focusing on aggression.
- Individual differences and developmental psychology must be considered when learning about issues such as aggression caused by an accident and how the function of structures of the brain can be affected by the environment.
Topic 3: Biological psychology exam tips
Examiner Tips
- 💡Aggression is the vehicle for this topic on the foundations paper, so frame every mechanism as an explanation of aggressive behaviour rather than as isolated physiology.
- 💡Keep the studies straight by researcher and method, since a question may ask you to compare a scanning study with a twin study and the method is what you compare.
- 💡Longer answers expect issues and debates, so have reductionism, determinism and nature with nurture ready to apply to the biological evidence.
- 💡This is a synoptic instruction, so expect a question that asks you to apply developmental or individual difference thinking to a biological explanation rather than to describe either alone.
- 💡Scenarios describing a person whose behaviour changed after an accident are common; name the region, name the effect and then qualify it with the limits of case evidence.
- 💡When you evaluate a case study, comment on generalisability and on the quality of the historical record rather than only saying the sample was small.
Common Mistakes
- Reporting the scanning study as showing that brain damage causes murder, when the sample was a selected group of defendants and the design was correlational.
- Writing that a gene for aggression exists, when the evidence concerns an enzyme that regulates neurotransmitter breakdown and its effect depends on environment.
- Generalising from rodent studies of aggression to human violence with no acknowledgement of the difference.
- Using biological determinism as a throwaway phrase without applying it to a consequence such as sentencing or treatment.
- Claiming a brain injury makes a person violent, when reported changes were to social conduct and self regulation and later evidence suggests substantial recovery.
- Describing the gene and environment study as showing a gene causes crime, which reverses the interaction the study was designed to show.
- Ignoring individual differences entirely and writing as though all people with similar damage behave alike.
- Confusing developmental psychology with childhood as a topic, so the answer never explains how development changes the biology.