Definitions of Abnormality

Deviation from statistical norms

This is an objective way of defining abnormality, whee a person’s trait, thinking or behaviour is classified as abnormal if it is rare or statistically unusual. It is difficult to decide the cut-off point which something is rare because it might no mean undesirable, such as high IQ.

Strengths:

• Quantitative data – can be analysed without bias.
• Clear definition – easy and simple to use.

Weaknesses: 

• Subjective – the admission of data relies on the psychologists’ diagnosis, therefore it might not be as reliable.
• Ungeneralisable – high levels of depression and anxiety are not rate but are considered abnormal.

Deviation from social norms

This labels people abnormal if their traits, thinking or behaviour does not fit with the cultural and social norms of one country and what is expected. Usually, behvaiours are incomprehensible or make others feel uncomfortable.

Strengths:

• Fluid – allows for changes a time goes on and social/cultural norms develop.
• Useful – it can help to find abnormalities and mental illnesses such as Alzheimer’s.

Weaknesses:

• Ungeneralisable – it depends on the social context and cultural relativism of each country/continent.
• Szasz (1974) claimed this definition is a form of social control and is therefore abusing of people’s behaviour.

Deviation from ideal mental health

This focuses more on what characteristics a person should have for ideal mental health and anything that deviates from that is regarded as abnormal. Jahoda (1958) noted that people with ideal mental health:

• Show no signs of distress in everyday life.
• Are rational 
• Are able to self-actualise
• Can cope with stress
• Have an accurate perception of reality.
• Have good self-esteem
• Have personal autonomy.

Failure to function adequately 

This states a person is abnormal if they are unable to cope with the demands of everyday life, such as showing signs of psychological distress. Rosenhan and Seligman (1989) suggested some characteristics that may show abnormality:

• Suffering 
• Maladaptiveness
• Unconventionality 
• Violation of moral standards 
• Irrationality 
• Unpredictability 

Strengths:

• Non-invasive 
• Fluid – the Global Assessment of Functioning is on a continuum and changes as new research is developed.

Weaknesses:

• Ungeneralisable – there may be exceptions to the rule, such as students suffering with anxiety because of their exams.
• Cultural issues – minorities in certain countries feel harassed and therefore are less social, but this does not mean they are abnormal.