Factors underlying abnormal behaviour

The essentials

No single cause explains psychological disorders. Psychologists look at biological, psychological and socio-cultural factors and the way they interact.

Key points

• Biological factors: faulty genes, structural problems in the brain, and imbalances of neurotransmitters (chemical messengers between neurons). Examples: low activity of GABA is linked with anxiety; excess dopamine activity with schizophrenia; low serotonin with depression.
• Psychological models:
• Psychodynamic: disorders arise from unconscious conflicts, especially among id, ego and superego, often rooted in childhood.
• Behavioural: abnormal behaviour is learnt through classical conditioning, operant conditioning and modelling.
• Cognitive: abnormal behaviour results from irrational assumptions and distorted ways of thinking.
• Humanistic-existential: problems arise when people fail to accept responsibility, find meaning or fulfil their potential.
• Diathesis-stress model: a biological predisposition (diathesis) combined with a stressor triggers the disorder. It has three components: the diathesis (a vulnerability), the stress (pre-dispositions are triggered by stressors), and the interaction of the two leading to the disorder.
• Socio-cultural factors: war, violence, poverty, prejudice, family disruption and social change can increase risk; social networks and support can protect.

Exam tips

• Remember neurotransmitter links: GABA–anxiety, dopamine–schizophrenia, serotonin–depression.
• In case questions, ask whether the explanation focuses on brain chemistry, learning, thoughts, unconscious conflicts or social conditions.

Common mistakes

• Thinking a diathesis alone causes a disorder; the model requires a stressor too.
• Assuming genetic influence means a disorder is inevitable.