Who would be exhibiting normal behavior under the statistical definition of abnormality?

Statistical definitions can be drawn on to determine whether an activity or psychological attribute deviates from the norm in society

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What is statistical infrequency and how does this help us to define mental health issues?

Researchers can use statistics to determine what is normal and abnormal. Statistical definitions can be drawn on to determine whether an activity or psychological attribute deviates significantly from the statistical norm in society.

If someone is classed as normal they score in line with the statistical norm, whereas if they are abnormal they display an attribute that appears infrequently in the statistics. For instance, when considering intellectual disability, if an IQ score is substantially under the norm of 100, this has been used in the past as one criterion.

Above: a graph showing the distribution of IQ among the population. The statistical norm is 100 (the peak of the graph). 68.26% of the population have an IQ between 85 and 115

Problems with the statistical infrequency approach

The statistical approach can be useful in helping us to determine a cut-off point in terms of diagnosis because anything that appears outside of the normal distribution curve is statistically rare behaviour. There are, however, still a number of problems with defining abnormality simply in terms of statistical infrequency.

First of all, this definition fails to distinguish between desirable and undesirable behaviour. It is only concerned with the frequency of it. For example, a high IQ is just as statistically abnormal as a very low one, but may well be regarded as highly desirable.

This definition also infers that the existence of abnormal behaviour in people should be rare or statistically unusual, which is not the case. Feelings of depression and anxiety that are highly prevalent in many mental health issues are not statistically rare (Davey, 2017). This is a further reason why statistical deviation is not an adequate way to define abnormality in mental health and mental health issues.

Subjective judgment

In addition, implementing a definition of abnormality that is formed upon statistics can misguide people to believe that it is empirically objective and measurable. However, a subjective judgment is being made whenever the line is drawn between what is considered to be abnormal and normal.

Who decides what is statistically rare and how do they decide? For example, if an IQ of 70 is the cut-off point, how can we justify saying someone with 69 is abnormal, and someone with 70 normal? (McLeod 2018).

Finally, exhibiting some form of prolonged abnormal behaviour at some point is common. This definition does not distinguish between rare, slightly odd behaviour and rare, psychologically abnormal behaviour (Faudemer et al. 2015) .

Using statistical methods to ascertain normality and abnormality can help us to understand how behavioural patterns are distributed through a population of people, but taken alone, this method might not be nuanced enough to define a persons mental health as normal or abnormal. Just because a behaviour is statistically unusual, is it abnormal?

References

Davey, G.,C. (2017) Psychopathology. 2nd edn. Chichester: Wiley

Faudemer, K., Hayden, C., McHale, K., and Simson, C. (eds.) (2015) A-Level Psychology: AQA Complete Revision and Practice. Newcastle Upon Tyne: CGP Books

McLeod, S. (2018) Abnormal Psychology [online]. available from https://www.simplypsychology.org/abnormal-psychology.html [16th November 2018]

© Coventry University. CC BY-NC 4.0

Section B - Psychopathology

Question 13: Outline and Evaluate [8 Marks] - Definitions of Abnormality

Suggested Answer: Two definitions of abnormality include statistical infrequency and and failure to function adequately (FFA). According to the statistical infrequency definition, a behaviour is seen as abnormal if it is statistically uncommon or not seen very often in society. For example, the average IQ is approximately 100 and 95% of the population have an IQ in the region of 70 to 130. However, a small percentage of the population (approximately 5%) have an IQ below 70 or above 130 and these people are statistically uncommon and therefore abnormal (according to this definition).

One problem with the concept of statistical infrequency is the issue of misdiagnosis. Certain behaviours are statistically common; for example, approximately 10% of the population will experience depression at some point making this behaviour ‘normal’, technically. On the other hand, certain behaviours - for example, high IQ - are statistically uncommon and therefore considered abnormal despite their desirable nature. This is a serious drawback of adopting the statistical infrequency definition of abnormality as certain behaviours (both favourable and less favourable) may be ‘incorrectly’ diagnosed.

According to the FFA definition, a person is considered abnormal if they are unable to cope with the demands of everyday life and live independently in society. Furthermore, to be classified as abnormal, a person’s behaviour should cause personal suffering and distress because of their failure to cope. However, they may also cause distress or discomfort to other people who observe their behaviour.

One weakness of the FFA definition is the notion of individual differences. For example, one person with Obsessive Compulsive Disorder (OCD) may exhibit excessive rituals that prevent them from functioning adequately, as they constantly miss work; whereas, another person may suffer from the same excessive rituals, but find time to complete their rituals and always attend work on time. Therefore, despite the same psychological and behavioural symptoms, each person would be diagnosed differently, thus questioning the validity of this definition. However, some psychologists argue that this is a strength because the definition takes into account the subjective personal experiences of the patient. This definition considers the thoughts and feelings of the person experiencing the issue and does not simply make a judgement, without taking the personal viewpoint of the sufferer into consideration. This suggests that the failure to function definition is a useful definition for assessing psychopathological behaviour as it takes into account these individual differences. 

Please Note: These answers have been produced without the knowledge of the mark scheme and merely reflect my attempt at producing a model answer on the day of the exam. These answers are not endorsed or approved by AQA.

What three criteria are commonly used to identify abnormal behavior?

Which of the following is one definition of abnormal behavior?

What is meant by the definition of abnormality as deviation from the ideal?

What is the primary difficulty with applying the criterion of unconventionality to define abnormal behavior?