Biological approach to understanding behaviour flashcards

Topic 1: Biological approach to understanding behaviour

What are the four topics of the biological approach?

The relationship between the brain and behaviour; hormones and pheromones and their effects on behaviour; the relationship between genetics and behaviour; and the role of animal research in understanding human behaviour (HL only).

What did Maguire et al. (2000) find about London taxi drivers?

Structural MRI showed taxi drivers had larger posterior hippocampi than controls, correlated with years of driving: evidence for the hippocampus’s role in spatial memory and for neuroplasticity.

What is the main limitation of Maguire et al. (2000)?

It is correlational, so it cannot rule out that people with naturally larger posterior hippocampi are more likely to become and stay taxi drivers.

What did the case of H.M. show about memory?

After surgery removed much of both hippocampi to treat epilepsy (1953), H.M. could not form new long-term memories (anterograde amnesia) but kept older memories and could learn new motor skills, suggesting memory systems are partly localised.

How should you explain a neurotransmitter’s role in behaviour?

As a two-part claim: what the chemical does physiologically at the synapse, then which specific behaviour that mechanism is proposed to explain. Naming the neurotransmitter alone is not enough.

Hormone vs pheromone

Hormone: a chemical messenger released by an endocrine gland into the bloodstream that acts within the same body, such as cortisol in the stress response. Pheromone: a chemical signal released by one individual that affects another of the same species.

Do humans have pheromones that affect behaviour?

It is contested. Candidates such as androstadienone have been studied, but no human pheromone has been conclusively identified, and expectation or context may explain apparent effects.

How do twin studies estimate a genetic contribution to behaviour?

They compare concordance rates for a trait between identical (monozygotic) twins, who share all their genes, and non-identical (dizygotic) twins, who share about half. Higher MZ concordance suggests a genetic contribution.

What did Caspi et al. (2003) find?

People with one or two short versions of the 5-HTT (serotonin transporter) gene were more likely to become depressed, but only after stressful life events: a gene-environment interaction. Later studies, such as Risch et al. (2009), failed to replicate it, so it is disputed.

What are the value and limits of animal research for understanding human behaviour?

Value: controlled tests not possible on humans, and many biological systems are shared across mammals. Limits: species differences limit generalisation, and harm to animals raises ethical questions judged by the 3Rs (replacement, reduction, refinement). (HL only)