Definitions of abnormality part 1

Statistical infrequency

- Any relatively usual behaviour or characteristic can be thought of as 'normal', and any behaviour that is unusual is 'abnormal', e.g. at any one time only a small number of people will have an irrational fear of buttons, for example

Statistical infrequency: IQ and intellectual disability disorder

- In terms of intelligence, we know that, in any human characteristic, the majority of people's scores will cluster around the average, and that the further we go above or below that average, the fewer people will attain that score (normal distribution). The average IQ is set at 100, in a normal distribution, most people have a score in the range from 85 to 115. Only 2% have a score below 70, meaning these are very unusual or 'abnormal', and are liable to receive a diagnosis of a psychological disorder

Deviation from social norms

- When a person behaves in a way that is different from how we expect people to behave. Groups of people choose to define behaviour as abnormal on the basis that it offends their sense of what is 'acceptable'. We are making a collective judgement about what is right

Deviation from social norms: Norms are specific to the culture we live in

- These may be different for each generation and different in every culture, so there are few behaviours that would be considered universally abnormal. E.g. homosexuality was considered abnormal in our culture in the past and continues to be viewed as abnormal (and illegal) in some cultures

Deviation from social norms: Antisocial personality disorder

- A person with this is impulsive, aggressive, and irresponsible. According to the DSM-5, one important symptom of this is an 'absence of prosocial internal standards associated with failure to conform to lawful and culturally normative ethical behaviour'. In other words, we are making the social judgement that psychopaths are abnormal because they don't conform to our moral standards

Evaluation of statistical infrequency: Strengths

- Real-world application. It is used in clinical practice, both as part of formal diagnosis and as a way to assess the severity of an individual's symptoms, e.g. a diagnosis of intellectual disability disorder requires an IQ of below 70 (bottom 2%). An example of this used in an assessment tool is the Beck depression inventory. A score of 30+ (top 5% of respondents) is interpreted as indicating severe depression

- This shows the value of the statistical infrequency criterion is useful in diagnostic and assessment processes

Evaluation of statistical infrequency: Weaknesses

- Infrequent characteristics can be positive as well as negative. For every person with an IQ below 70 there is another with an IQ above 130. Yet we would not think of someone as abnormal for having a high IQ. Similarly, we would not think of someone with a very low depression score on the BDI as abnormal. These examples show that being unusual or at one end of a psychological spectrum does not make someone abnormal

-This means that, although statistical infrequency can form part of assessment and diagnostic procedures, it is never sufficient as the sole basis for defining abnormality

Evaluation of deviation from social norms: Strengths

- Real-world application. Deviation from social norms is used in clinical practice, e.g. the key defining characteristic of antisocial personality is the failure to conform to culturally acceptable ethical behaviour (recklessness, aggression, etc). These signs of the disorder are all deviations from social norms. Such norms also play a part in the diagnosis of schizotypal personality disorder, where the term 'strange' is used to characterise the thinking, behaviour, and appearance of people with the disorder

- This shows that the deviation from social norms criterion has value in psychiatry

Evaluation of deviation from social norms: Weaknesses

- The variability between social norms in different cultures and even different situations. A person from one cultural group may label someone from another group as abnormal using their standards rather than the person's standards, e.g. hearing voices is the norm in some cultures but would be seen as abnormal in most parts of the UK. Also, even within one cultural context social norms differ from one situation to another. Aggressive and deceitful in the context of family life is more socially unacceptable than in the context of corporate deal-making

- This means it is difficult to judge deviation from social norms across different situations and cultures