Abnormality : What is it? (06-Mar-2003)

While on the face of it, "abnormality" sounds like an easy thing to define, in fact there are many different techniques used by psychologists to classify behaviour, or mental health, as "abnormal". All of these have their strengths and weaknesses; there is no one "right" way to define abnormality. Some of the most common are:

Statistical

In some cases it is possible to gather data in a numeric form and derive a mean average value. We can then say that the majority of values which are nearest to the mean are "normal", and the minority of values farthest from the mean are "abnormal". For example, if the average height of a set of people is five foot eight, with most values falling in the range four feet to six foot six, then a height of less than three foot or more than eight foot would or probably be considered "abnormal".

One problem with the statistical approach is that the decision of where to start the "abnormal" classification is arbitrary. Typically, abnormal values are considered to be anything with a standard deviation of greater than 2. Applying this measure to values of IQ, which have a bell-curve distribution around a mean of 100, values of lower than 70 or greater than 130 are classified as "abnormal".

An important consideration of statistically "abnormal" values is that "abnormal" doesn't necessarily mean undesireable. For example, someone with an IQ of 131 is statistically abnormal, but may well be regarded as gifted.

Another problem with this method is that behaviour which is undesireable may be statistically frequent. For example, depression is regarded as undesireable, yet it is not uncommon enough to be classified as abnormal in the statistical sense.

Deviation from Social Norm

A social norm is an unwritten rule which governs behaviour in a given social context (see Conformity). Using this definition, behaviour which breaks these rules is regarded as abnormal.

Strengths of this technique:

Some of the problems with this technique are :

Deviation from Ideal Mental Health

In this context, "normal" can be taken to mean "mentally healthy", while "abnormal" describes an undesireable state which is somehow deficient from "mental health". This approach therefore attempts to describe the characteristics which constitute "ideal" mental health.

This approach is characteristic of humanistic psychologists such as Maslow, who defined his heirarchy of needs (e.g. physiological, safety, love, esteem, self-fulfillment) as a means of assessing whereabouts an individual was on their path to self-actualisation, which he regarded as the ideal state. However, a problem with this approach is that very few people would be considered "normal" by this measure, because few people achieve self-actualisation as Maslow defines it.

In a slightly different approach, Jahoda defined six criteria by which mental health could be measured:

According to this approach, the more of these criteria are satisfied, the healthier the individual is.

An advantage of this type of approach is that it does provide areas to target when treating depression, and it focuses on a positive approach to the problems. On the other hand, like Maslow's criteria, very few people are likely to achieve all six of Jahoda's objectives, and it is also hard to measure the extent to which an individual misses these criteria.

Another criticism of Jahoda is that some of the criteria might be seen to be ethnocentric: for example, autonomy is seen in some cultures as an undesireaeble trait.

Failure to Function Adequately

Using this set of criteria, behaviour is defined as abnormal if it hurts the person himself or other people. Rosenhan & Seligman listed seven criteria:

Strengths of this technique include: Weaknesses:

Homework

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