Behavioural sciences chapters
The biopsychosocial model and the role of behavioural sciences
Why doctors need behavioural sciences, the biomedical and biopsychosocial models of health, the systems approach, normality versus abnormality, and how psychology, sociology and anthropology link to health.
- Behavioural sciences (psychology, sociology, anthropology) study how people think, feel and behave, and how this affects health, illness and care.
- The biomedical model sees disease only as a biological fault; the biopsychosocial model (Engel, 1977) adds psychological and social factors and treats the whole person.
- The systems approach sees a person as part of linked systems (cells, organs, person, family, community), so a change at one level affects the others.
On this page
Overview
Two patients with the same disease can have very different illnesses: one copes and recovers, another becomes depressed, misses treatment and does badly. The difference often lies in thoughts, feelings, behaviour, family and culture.
Behavioural sciences study these factors. They help doctors understand patients, communicate well, improve adherence and look after their own well-being.
The behavioural sciences
| Science | Focus | Health examples |
|---|---|---|
| Psychology | The individual: thinking, emotion, learning, personality, behaviour | Stress and illness, pain perception, adherence, health beliefs |
| Sociology | Groups and society: family, social class, roles, institutions | Poverty and health, the sick role, health inequalities, stigma |
| Anthropology | Culture: beliefs, customs and values of communities | Beliefs about the evil eye, traditional healers, rituals around birth and death |
Anthropology studies culture; sociology studies society and groups; psychology studies the individual mind and behaviour.
The biomedical model
The traditional model of Western medicine:
- Disease is a biological abnormality (germs, genes, injury).
- The doctor's job is to diagnose and fix the fault.
- Mind and body are treated as separate (mind-body dualism).
It has been very successful (antibiotics, surgery, vaccines) but does not explain why people with the same disease behave differently, why some have symptoms without disease, or why social conditions affect health so strongly.
The biopsychosocial model
Proposed by George Engel in 1977. Health and illness result from the interaction of three groups of factors:
- Biological: genes, infection, physiology, injury, drugs.
- Psychological: thoughts, emotions, coping, beliefs, personality, behaviour (smoking, diet, adherence).
- Social: family, work, income, education, culture, religion, social support.
The model encourages holistic, patient-centred care: treating the person, not just the disease.
Example: a man with poorly controlled diabetes. Biological: insulin resistance. Psychological: low mood and denial. Social: cannot afford medicines, irregular meals during long shifts. All three need attention.
The biopsychosocial model (Engel) looks at biological, psychological and social factors together.
The systems approach
The person is seen as one level in a hierarchy of linked systems:
molecules → cells → organs → person → family → community → society → culture.
Each level affects and is affected by the others. For example, a father's heart attack (organ level) affects his mood (person), his family's income (family) and their children's schooling (community).
Brain, mind and behaviour
- The brain is the physical organ.
- The mind is the set of mental processes (thinking, feeling, perceiving, remembering) that arise from brain activity.
- Behaviour is what we observably do.
They are closely linked: brain injury or drugs change mind and behaviour, while thoughts and stress change brain chemistry, hormones and immunity (psychoneuroimmunology).
Normality and abnormality
There is no single definition of "normal". Common criteria:
| Criterion | Meaning | Limitation |
|---|---|---|
| Statistical | Normal = what most people do (the average) | Rare can be good (high intelligence) |
| Ideal (perfection) | Normal = an ideal state of health | Hardly anyone meets it |
| Social (cultural) norms | Normal = what society accepts | Varies across cultures and times |
| Functional | Abnormal = behaviour that causes distress or impairs functioning | Judgement of impairment can vary |
Behaviour normal in one culture (for example certain religious experiences or mourning rituals) may look abnormal to an outsider. Always consider the cultural context before calling behaviour abnormal.
Illness behaviour and the sick role
- Illness behaviour: how people notice, interpret and act on symptoms (seeing a doctor, a hakeem, a pir, or doing nothing).
- The sick role (Parsons): the sick person is excused from normal duties and not blamed for the illness, but is expected to want to get well and seek and cooperate with help.
Why behavioural sciences matter to doctors
- Better communication and doctor-patient relationships.
- Understanding adherence and lifestyle change.
- Recognising the role of stress and mental health in physical illness.
- Respecting culture and beliefs.
- Breaking bad news, handling difficult patients, and ethics.
- Looking after the doctor's own well-being and avoiding burnout.
Expect: the three behavioural sciences and what each studies, the biomedical vs biopsychosocial model, Engel (1977), recognising the biopsychosocial approach in a scenario, the systems approach, and criteria of normality and abnormality.
Quick revision
- Behavioural sciences: psychology (individual), sociology (society), anthropology (culture).
- Biomedical model: biology only; mind-body dualism.
- Biopsychosocial model (Engel, 1977): biological + psychological + social.
- Systems approach: linked levels from cell to society.
- Normality: statistical, ideal, social, functional criteria.
- Sick role (Parsons): excused duties, but must seek help and want recovery.
Written by The House Job from the Handbook of Behavioural Sciences by Mowadat H Rana (named in the UHS PGET syllabus).
FAQ
What is the biopsychosocial model?
A model of health and illness, proposed by George Engel in 1977, that considers biological, psychological and social factors together.
What do the behavioural sciences include?
Mainly psychology, sociology and anthropology, as applied to health and medicine.
How is abnormal behaviour defined?
By several criteria: statistical rarity, departure from an ideal, breach of social norms, and distress or impaired functioning.
What is the systems approach in health care?
Viewing a person as part of linked systems, from cells and organs to family and society, so that change at one level affects the others.