All subjects · Psychology · WPS04 Clinical Psychology and Psychological Skills

Issues and debates: reductionism, holism and different explanations

Edexcel IAL Psychology · WPS04 Clinical Psychology and Psychological Skills

Spec 9.3.3 (reductionism versus holism) and 9.3.4 (ways of explaining behaviour using different approaches, models or theories). The component guide suggests using these when evaluating explanations, for example reductionism in the dopamine hypothesis.

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Reductionism and holism

Reductionism explains behaviour by breaking it into smaller parts: neurotransmitters, genes, brain areas, or stimulus-response links.
Holism looks at the whole person and how factors interact: biology, thinking, family, culture, gender, social status and age.

Reductionism: for it allows precise, testable hypotheses and scientific methods (experiments, scans) and has led to treatments (antipsychotics, SSRIs). Against: it oversimplifies; it may confuse correlation with cause (does low serotonin cause depression or result from it?).

Holism: for it captures complexity and interaction (diathesis-stress, family therapy). Against: it is hard to test scientifically and to turn into precise treatments.

Examples across the course

Behaviour	Reductionist explanation	More holistic explanation
Schizophrenia	Dopamine hypothesis; genes	Diathesis-stress; expressed emotion and family therapy
Depression	Monoamine hypothesis	Beck's triad plus life events; social support (Ma et al.)
Aggression	MAOA gene, brain structure (Raine et al.)	SLT plus biology; twin studies show both (Brendgen et al.)
Memory	Multi-store model boxes	Reconstructive memory and schemas (Bartlett)
Phobias	Classical conditioning (Watson and Rayner)	Conditioning plus cognition and SLT

Different ways of explaining behaviour (9.3.4)

Behaviour can be explained by different approaches, and each has strengths:

Aggression: biological (hormones, genes, brain), learning (SLT), social (obedience, conformity).
Memory: multi-store model, working memory model, reconstructive memory.
Schizophrenia: dopamine, glutamate, genes, brain structure, family environment.
Phobias: classical conditioning, SLT, psychodynamic (Little Hans).

Comparing explanations shows that one approach rarely explains everything; combined (interactionist) explanations are usually strongest.

Worked example

Evaluate the dopamine hypothesis in terms of reductionism.

It is reductionist: it explains a complex disorder through one neurotransmitter.
Strength: this made it testable and led to antipsychotics, which help many people.
Weakness: it cannot explain why stress or family environment affects relapse, or why 58% of MZ co-twins in Gottesman and Shields were not diagnosed.
Judgement: useful as part of an explanation, but a holistic diathesis-stress account fits the evidence better.

Answer: Describe, give for and against with evidence, then judge.

Key idea: Reductionism breaks behaviour into parts (genes, neurotransmitters): testable and useful but oversimplified. Holism considers interacting factors: realistic but hard to test. Most behaviours (aggression, memory, schizophrenia, phobias) have several competing explanations.

Check yourself

Which explanation is most reductionist?
- Depression results from interacting genes, thinking styles and life events
- Schizophrenia relapse depends on family stress and medication
- Aggression involves biology, learning and culture
- Depression is caused by low serotonin
Show answer
Depression is caused by low serotonin. One chemical explains the behaviour.
Which is a weakness of holistic explanations?
- They ignore all social factors
- They are hard to test scientifically
- They focus on a single gene
- They cannot be applied to people
Show answer
They are hard to test scientifically. Many interacting variables are hard to isolate.
Which treatment best reflects a more holistic view of schizophrenia?
- A single antipsychotic only
- Brain surgery
- No treatment
- Family therapy alongside medication
Show answer
Family therapy alongside medication. It considers biology and the social environment.
Which pair shows different explanations of the same behaviour?
- The multi-store model and reconstructive memory as explanations of memory
- Rosenhan and Suzuki as studies of schizophrenia
- SSRIs and tricyclics as antidepressants
- Mean and median as averages
Show answer
The multi-store model and reconstructive memory as explanations of memory. Two theories of memory.
Explain one strength of reductionist explanations of behaviour.
Show answer
They break behaviour into measurable parts such as neurotransmitters, which allows scientific testing and has led to effective treatments such as drug therapy.. Testability and practical application.

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Last updated 8 November 2026. Spotted a mistake? Tell us.