What are the causes of abnormal behaviour?

There are primarily seven psychological perspectives of abnormal behaviour. All these perspectives indicate different factors as the causes of abnormal behaviour. Additionally, Stress Diathesis Model and Biopsychosocial Model also discuss the causes of abnormal behaviour.

The causes of abnormal behaviour can be explained as follows:

• Biological perspective: Abnormal behaviour results due to chemical imbalance or physiological factors. 
• Sociocultural perspective: Abnormal behaviour is learnt within the social context.
• Behavioural perspective: Abnormal behaviour is learnt due to ineffective learning and conditioning.
• Evolutionary perspective: Abnormal behaviour is an exaggerated form of adaptive action.
• Humanistic perspective: Abnormal behaviour arises from blocked personal growth.
• Psychoanalytic/Psychodynamic perspective: Abnormal behaviour is due to unconscious and unresolved conflicts.
• Cognitive perspective: Abnormal behaviour arises due to false assumptions and faulty thinking. 
• Stress-Diathesis model: Disorder = Nature (Biological and genetic factors) + Nurture (Life experiences) 
• Biopsychosocial model: Abnormal behaviour = Biological factors + Psychological factors + Sociocultural factors