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Definitions of abnormality
Specification
Definitions of abnormality, including deviation from social norms, failure to function
adequately, statistical infrequency and deviation from ideal mental health.
Statistical infrequency
Rarity
When considering statistical infrequency the focus is on rarity. If very few people
are deemed to show the behaviour or thinking, it is described as abnormal.
Normal distributions
Some psychologists argue that most human traits are distributed along a normal
curve (a normal distribution). Their job is to first establish the norm and, once they
have done so, then they have an idea of what is not common i.e. abnormal.
Most people are in the central group, clustered around the mean, and fewer
people are at either extreme. Displaying behaviour or thinking thoughts that can be
placed at an extreme constitutes being abnormal.
2 standard deviations
Psychologists here use up-to-date statistics. It is even argued that people who are
2 standard deviations above or below the mean (i.e. in the extreme 2.145% of the
population) are abnormal.
Example-IQ
The average IQ is set at 100. Most people (68%) have an IQ in the range from 85
to 115. Only 2% of people have a score below 70.
Those individuals scoring below 70 are very unusual or ‘abnormal’, and are liable
to receive a diagnosis of a psychological disorder-intellectual disability disorder.
Evaluation of statistical infrequency
Negative
1. Fails to distinguish between rare
desirable and rare undesirable
behaviour
The definition fails to distinguish
between rare desirable and rare
undesirable behaviour. For example,
few people have an IQ of over 130 but
we would not want to suggest that this
is undesirable.
, 2
Equally there are some normal
behaviours that are undesirable. For
example depression is relatively
common and yet it is undesirable.
To treat people you would need some
way of measuring infrequent and
undesirable behaviours. This method
only accounts for infrequent behaviours.
In addition, hylophobia (fear or phobia
about forests or wood), which is very
rare, is regarded as a strong sign of
abnormality. In contrast, contemplating
suicide (which is less rare) is regarded
as less indicative of abnormality. This
makes no sense. What is omitted from
the statistical approach is any
assessment of the severity of symptoms
as well as their infrequency.
Positive Negative
1. Objectivity 2. Where to draw the line?
The definition relies on real, unbiased Another limitation is where to draw the
data and so is an objective means of line. Why should being in the bottom
defining abnormality. 2.145% be seen as abnormal, but not
being in the bottom 5%?
This compares favourably with the three
other definitions of abnormality that all Would you refuse treatment to these 5%
rely on subjective judgment. because they are not abnormal
enough?
For example, it is a matter of opinion
how far a behaviour deviates from Someone has to decide on a cut-off
social norms. point which means that some element
of subjectivity enters into this method
(which, consequently, is not as objective
as some would like it to be).
Other evaluation
Definitions of abnormality
Specification
Definitions of abnormality, including deviation from social norms, failure to function
adequately, statistical infrequency and deviation from ideal mental health.
Statistical infrequency
Rarity
When considering statistical infrequency the focus is on rarity. If very few people
are deemed to show the behaviour or thinking, it is described as abnormal.
Normal distributions
Some psychologists argue that most human traits are distributed along a normal
curve (a normal distribution). Their job is to first establish the norm and, once they
have done so, then they have an idea of what is not common i.e. abnormal.
Most people are in the central group, clustered around the mean, and fewer
people are at either extreme. Displaying behaviour or thinking thoughts that can be
placed at an extreme constitutes being abnormal.
2 standard deviations
Psychologists here use up-to-date statistics. It is even argued that people who are
2 standard deviations above or below the mean (i.e. in the extreme 2.145% of the
population) are abnormal.
Example-IQ
The average IQ is set at 100. Most people (68%) have an IQ in the range from 85
to 115. Only 2% of people have a score below 70.
Those individuals scoring below 70 are very unusual or ‘abnormal’, and are liable
to receive a diagnosis of a psychological disorder-intellectual disability disorder.
Evaluation of statistical infrequency
Negative
1. Fails to distinguish between rare
desirable and rare undesirable
behaviour
The definition fails to distinguish
between rare desirable and rare
undesirable behaviour. For example,
few people have an IQ of over 130 but
we would not want to suggest that this
is undesirable.
, 2
Equally there are some normal
behaviours that are undesirable. For
example depression is relatively
common and yet it is undesirable.
To treat people you would need some
way of measuring infrequent and
undesirable behaviours. This method
only accounts for infrequent behaviours.
In addition, hylophobia (fear or phobia
about forests or wood), which is very
rare, is regarded as a strong sign of
abnormality. In contrast, contemplating
suicide (which is less rare) is regarded
as less indicative of abnormality. This
makes no sense. What is omitted from
the statistical approach is any
assessment of the severity of symptoms
as well as their infrequency.
Positive Negative
1. Objectivity 2. Where to draw the line?
The definition relies on real, unbiased Another limitation is where to draw the
data and so is an objective means of line. Why should being in the bottom
defining abnormality. 2.145% be seen as abnormal, but not
being in the bottom 5%?
This compares favourably with the three
other definitions of abnormality that all Would you refuse treatment to these 5%
rely on subjective judgment. because they are not abnormal
enough?
For example, it is a matter of opinion
how far a behaviour deviates from Someone has to decide on a cut-off
social norms. point which means that some element
of subjectivity enters into this method
(which, consequently, is not as objective
as some would like it to be).
Other evaluation
