How does the biological approach explain behaviour through genes, brain structure, neurochemistry and evolution, and how does it treat disorders?
The biological approach: assumptions (genes, brain structure and localisation, neurochemistry, evolution), the named therapy (drug therapy/chemotherapy), application to behaviour, and evaluation. AS content.
An Eduqas A-Level Psychology answer to the biological approach in Component 1. Covers the four assumptions (genes, brain structure and localisation, neurochemistry and evolution), drug therapy as the named treatment, applications to behaviour, and a balanced evaluation for the Past to Present paper.
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What this dot point is asking
The biological approach is the first of the five approaches in Component 1, and it is AS content. You must know its assumptions, its named therapy (drug therapy), how it applies to behaviour, and how to evaluate it. Component 1 questions ask you to describe the assumptions, apply them to a behaviour, and evaluate the approach.
The answer
Assumptions
Each assumption gives a different physical cause of behaviour, and Eduqas expects you to apply them to real examples.
The named therapy: drug therapy
Application to behaviour
The approach applies its assumptions to explain many behaviours. Aggression can be explained by genes, by reduced prefrontal functioning, and by neurotransmitters and hormones (low serotonin, high testosterone). Depression can be explained by a serotonin imbalance and by heritability shown in twin studies. Mate choice and parental care can be explained by evolution. The approach is the foundation for biological explanations across Component 3 behaviours such as schizophrenia and addiction.
Evaluation
- Scientific. Uses objective, measurable methods (scans, assays, twin studies), giving reliable, replicable evidence.
- Useful applications. Drug therapies relieve symptoms for many patients and allow some to live independently.
- Reductionist. Reduces complex behaviour to genes or chemicals, ignoring environment, cognition and free will.
- Correlation not cause. Links such as low serotonin and depression are correlational, so the imbalance might be an effect, not a cause.
- Treatment limits. Drugs may mask symptoms without addressing causes and can have side effects, and stopping them often brings relapse.
Examples in context
Example 1. Why drug therapy follows from the assumptions. Because the approach assumes disorders have a biological cause (a chemical imbalance), the logical treatment is to change the biology. SSRIs raising synaptic serotonin in depression is a direct application of the neurochemistry assumption, which is why Eduqas pairs each approach with a therapy that flows from its assumptions.
Example 2. The contrast with the behaviourist approach. Where the biological approach explains a phobia as inherited vulnerability plus neurochemistry, the behaviourist approach explains the same phobia as a learned association. Comparing them shows the nature side of the nature-nurture debate, and why combining approaches gives a fuller explanation than either alone.
Try this
Q1. Name the four assumptions of the biological approach. [4 marks]
- Cue. Genes influence behaviour; brain structure (localisation of function) affects behaviour; neurochemistry affects behaviour; evolution shapes behaviour.
Q2. Explain how SSRIs are thought to treat depression. [3 marks]
- Cue. SSRIs block the reuptake of serotonin so more remains in the synapse, increasing serotonin activity and raising mood, correcting the assumed imbalance.
Q3. State one strength and one weakness of the biological approach. [2 marks]
- Cue. Strength: it is scientific and uses objective methods; weakness: it is reductionist and relies on correlational evidence, so cause and effect are unclear.
Exam-style practice questions
Practice questions written in the style of WJEC Eduqas exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.
Eduqas 20198 marksDescribe the assumptions of the biological approach. [8 marks]Show worked answer →
A description item testing the assumptions (AO1). Eduqas rewards the named assumptions, each explained and ideally illustrated.
The biological approach assumes behaviour has a physical basis. Four assumptions:
(1) Genes influence behaviour: characteristics and predispositions are inherited, so traits such as intelligence or vulnerability to disorder can be partly heritable (evidenced by twin and family studies).
(2) Brain structure affects behaviour through localisation of function: specific regions are responsible for specific functions (for example the prefrontal cortex for impulse control), so damage or difference in a region changes behaviour.
(3) Neurochemistry affects behaviour: neurotransmitters and hormones regulate mood and behaviour, so an imbalance (for example low serotonin) is linked to disorders such as depression.
(4) Evolution shapes behaviour: behaviours that aided survival and reproduction were naturally selected and passed on, so some behaviours are adaptive.
Markers reward each assumption named and explained, with brief evidence or an example for the higher band.
Eduqas 202112 marksEvaluate the biological approach in psychology. [12 marks]Show worked answer →
A balanced evaluation (AO3) reaching a judgement.
Strengths: it is highly scientific, using objective, measurable methods (brain scans, biochemical assays, twin studies), giving reliable, replicable evidence; it has produced effective applications, especially drug therapies that relieve symptoms for many patients; and it explains behaviour with precise, testable mechanisms.
Weaknesses: it is biologically reductionist, reducing complex behaviour to genes or chemicals and ignoring environment, cognition and free will; much evidence is correlational (for example low serotonin and depression), so cause and effect are unclear and the chemical imbalance could be an effect rather than a cause; and treatments such as drugs may relieve symptoms without addressing underlying causes and can have side effects.
A strong answer concludes that the biological approach is rigorous and clinically useful but incomplete on its own, best combined with psychological explanations. Markers reward developed points with a judgement.
Related dot points
- The behaviourist approach: assumptions (blank slate, classical conditioning, operant conditioning), the named therapy (aversion therapy/systematic desensitisation), application to behaviour, and evaluation. AS content.
An Eduqas A-Level Psychology answer to the behaviourist approach in Component 1. Covers the assumptions (blank slate, classical conditioning via Pavlov, operant conditioning via Skinner), aversion therapy as the named treatment, applications to behaviour, and a balanced evaluation for the Past to Present paper.
- The cognitive approach: assumptions (information processing/computer analogy, internal mental processes, schemas), the named therapy (cognitive behavioural therapy), application to behaviour, and evaluation. AS content.
An Eduqas A-Level Psychology answer to the cognitive approach in Component 1. Covers the assumptions (the computer analogy, internal mental processes and schemas), cognitive behavioural therapy as the named treatment, applications to behaviour, and a balanced evaluation for the Past to Present paper.
- The psychodynamic approach: assumptions (unconscious mind, tripartite personality, psychosexual stages, defence mechanisms), the named therapy (psychoanalysis/dream analysis), application to behaviour, and evaluation. A2 content.
An Eduqas A-Level Psychology answer to the psychodynamic approach in Component 1. Covers the assumptions (the unconscious, the id-ego-superego, psychosexual stages and defence mechanisms), psychoanalysis as the named treatment, applications to behaviour, and a balanced evaluation for the Past to Present paper.
- The positive approach: assumptions (free will and the good life, focus on the positive, the three pillars, signature strengths and the role of flow), the named applications (mindfulness, building signature strengths), and evaluation. A2 content.
An Eduqas A-Level Psychology answer to the positive approach in Component 1. Covers the assumptions (free will, the good life, the three pillars and signature strengths), mindfulness and strengths-based interventions as the named applications, and a balanced evaluation for the Past to Present paper.
- Classic research for the biological approach: Raine et al. (1997), Brain abnormalities in murderers indicated by positron emission tomography. Aim, method, results, conclusions and evaluation.
An Eduqas A-Level Psychology answer to the classic biological research, Raine et al. (1997), on brain abnormalities in murderers using PET scans. Covers the aim, the quasi-experiment with NGRI participants, the PET findings, conclusions about brain dysfunction and violence, and a balanced evaluation.
Sources & how we know this
- Eduqas GCE A Level in Psychology (A290) specification — Eduqas (2015)