The biological approach: assumptions, application to the formation of relationships, the therapy of drug treatment, the classic study of Raine et al. (1997), and evaluation.

What this dot point is asking

WJEC Unit 1 treats each approach the same way. For the biological approach you must do five things: state its assumptions, apply it to the formation of relationships, describe one therapy (drug therapy), describe the classic study of Raine et al. (1997), and evaluate it. The same five headings recur for the other approaches, so learn the template once.

Assumptions

The approach rests on four linked assumptions:

• The brain and localisation of function. Specific regions control specific behaviours, so damage to a region changes behaviour. Examiners like the example of the frontal lobes in impulse control.
• Neurochemistry. Behaviour is influenced by neurotransmitters (such as serotonin in mood and dopamine in reward) and by hormones (such as testosterone in aggression and cortisol in stress).
• Genes. Behaviour is inherited. Twin studies compare identical (MZ) and non-identical (DZ) twins to estimate the heritability of a behaviour; higher MZ concordance suggests a genetic component.
• Evolution. Behaviours that aided survival and reproduction were naturally selected and passed on, so some behaviour is adaptive and inherited from our ancestors.

Application to the formation of relationships

The biological approach explains why we form relationships through evolution and neurochemistry. Evolutionary psychology argues that mate choice is shaped by reproductive success: we are attracted to cues of fertility and good genes, such as youth and symmetry in women and resources and status in men, because ancestors with these preferences left more offspring. Sexual selection explains differing strategies, with the sexy sons hypothesis and parental investment theory predicting that women are choosier because they invest more in each child.

Neurochemistry adds the bonding mechanism. Oxytocin, released during physical closeness, promotes attachment and trust, while dopamine in the reward pathway makes early romantic love feel rewarding. So relationships form because they were adaptive and because the chemistry of bonding rewards them.

Therapy: drug treatment

The therapy derived from the biological approach is drug treatment, which works by changing neurochemistry. SSRIs (selective serotonin reuptake inhibitors) treat depression by blocking the reuptake of serotonin at the synapse, leaving more serotonin available to bind to receptors and lift mood. Antipsychotics reduce dopamine activity to treat the positive symptoms of schizophrenia, and anti-anxiety drugs such as benzodiazepines enhance the inhibitory neurotransmitter GABA to reduce arousal.

Drug therapy is cheap, convenient and effective for many patients, which is a major real-world strength of the approach. Its weaknesses are side effects, the risk of dependence, and that it treats symptoms rather than causes, so relapse is common once the drug stops.

Classic study: Raine et al. (1997)

This study supports the assumption that brain structure relates to behaviour and uses objective imaging, but Raine himself stressed it does not prove murderers are "born", cannot rule out environmental causes, and used a specific legal sample, limiting generalisation.

Evaluation

Examples in context

Example 1. Depression and SSRIs. Low serotonin is associated with depression, so SSRIs that raise serotonin often improve mood, tracing assumption (neurochemistry affects behaviour) to therapy to outcome.

Example 2. Aggression and testosterone. Higher testosterone is associated with greater aggression in some studies, fitting the neurochemical assumption, but the link is correlational and social learning also explains aggression.

Try this

Q1. State one assumption of the biological approach. [1 mark]

• Cue. Behaviour has a physical basis, for example in neurotransmitters, genes, the brain or evolution.

Q2. Outline how the biological approach explains the formation of relationships. [3 marks]

• Cue. Evolutionary advantage and mate choice for reproductive success, plus bonding through oxytocin and reward through dopamine.

Q3. Briefly evaluate the use of Raine et al. (1997) as evidence for the biological approach. [4 marks]

• Cue. Strength: objective brain imaging. Weaknesses: correlational, a specific NGRI sample, and Raine's own caution that biology is not the sole cause.