WJEC AS Psychology PY1 - Biological Approach

Notes for the Biological Approach including assumptions, theory, therapy, methodology, 2 strengths and 2 weaknesses


Biological Approach - Assumptions

Assumption 1 - Chemicals in our brian and body have a huge impact on our behaviour.

The Endocine system secretes hormones into our bloodstream. Too much or too little can lead to psychological problems.

eg. Excessive dopamine appears to be involved in the mental illness schizophrenia.

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Biological Appraoch - Assumptions

Assumption 2 - all behaviour has a physical cause

4 lobes of the brain: frontal, occipital, parietal and temporal lobe

different parts of the brain linked to different functions. This is called Localisation.

Therefore, if there is damage to a specific part of the brain, this can have an

Example: damage to occipital lobe can affect sight, 

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Biological Approach - Theory

Theory - Selye's General Adaptation Syndrome

Stress:when our body encounters stressors it doesn't think it can cope with , it experiences physiological and psychological responses to adapt to the environment

Selye (1947):did an experiment with rats where they were exposed to stressors (heat, fatigue); found they produced the same response regardless of stressor and the initial changes were increased pulse rate, blood pressure and breathing rate

Developed 3 phases in the body's response to stress if stressor persists:

  • Alarm Reaction: immediate activation by body to deal with stressor
  • Resistance Stage: attempt by body to return to steady state despite stressor persisting
  • Exhaustion Stage: failure to return to normal physical state in ongoing presence of stressor that causes depletion of bodily resources
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Biological Approach - Theory Continued

Alarm Reaction:
- stressor is detected & body stress response is activated to prepare for fight or flight > Hypothalamus sets off the stress response > Hypothalamus activates the sympathetic branch of the ANS > the release of adrenaline > increase of heart rate and blood pressure. 

Resistance Stage:
- stressor persists > pituitary gland release ACTH > makes cortisol which makes energy more available > resources are gradually being used up & the body may be deteriorating.

Exhaustion Stage:
- stressor continues > alarm symptoms may reappear, along with damage to the adrenal glands > immune system weakened > increases risk of heart disease, depression, uclers

- Link between psychological factors with physical illnesses

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Biological Approach - Therapy

Therapy: Psychosurgery (in particular transorbital lobotomy)
Link: "All behaviour as a physical cause". Therefore, one way to treat abnormal behaviour is to alter the structure of the brain.
Aim: To surgically alter the brain in order to treat psychologically disturbed behaviour. Done by destroying sections or seperating connections between different areas of the brain. Can treat OCD and depression. History: 1940/50s Moniz heard about research where aggressive monkeys had been subdued after their frontal lobes were removed. adpated a similar one for humans. Developed further by Freeman (ice-pick technigue) in which an ice pick was inserted into the tear duct and then moved around to sever connections between the pre-frontal cortex and the rest of the brain. Effectiveness: Prefrontal lobotomies have 6% fatality rate, as well as possiblities of side effects. Mayberg (2005) found that deep brain stimulation was effective for 4 out of 6 patients with severe depression.

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Biological Approach - Therapy Continued

Description of therapy: types of psychosurgery include prefrontal lobotomy, Stereotatic psychosurgery and deep brain stimulation.

  • Prefrontal Lobotomy: destroying nerve fibres in the frontal lobe (associated with impulse control and mood). instrument has evolved over time from an ice-pick(transorbital) to a leucotome (retractable wire loop).
  • Stereotatic psychosurgery: more recent treatment and involves using MRI scans to find exact points in the brain before severing connections under anaesthetic. could be done by burning away tissue or using a non-invasive tool like a gamma knife.
  • Deep brain stimulation: no tissue is destroyed. Surgeons thread wires through the brain which then interrupt the brain circuitry.
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Biological Approach - Methodology

Lab experiments: a study in a controlled environment where we try to isolate one variable (IV) to see what effect it has on another variable (DV)


  • Highly controlled. this means we have high internal validity.
  • because they are so highly controlled it means we can replicate them easily. This makes the results reliable.


  • in an artificial setting. means they are low in ecological validity.
  • use of animals (Selye). cant compare the two because human brains are much more complex. not possible to generalise the results.
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Biological Approach - Methodology Continued

Brain scans: include CAT scans = taking x-rays, MRIs = use maganetic scans and PET scans = giving the patient slightly radioactive glucose & then tracking this to find levels of activity in the brain.


  • give us a detailed insight into the brain
  • allows us to look at an active living brain


  • scans can be time consuming and expensive
  • can only be done a few times becase of the radioactive glucose
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Biological Approach - Strengths

The Biological approach is scientific

  • uses objective research methods such as brain scans, blood tests, lab experiments. this is a strength because the theories and research is based on evidence and gives its realiablity.

The Biological appraoch has been applied usefully

  • has produced lots of usefully applications. for example, reseach into stress has developed stress-management treatments and research into mental disorders has led to the development of psychiatric drugs such as anti depressents. this is a strength because people who would have experience suffereing due to mental disorders can now live more managable lives.
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have you got cards for chemotherapy as a therapy instead of psychosurgery?

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