Slides in this set
The assumption is that any human characteristic is spread
in a normal way across the general population.
When the incidence of that characteristic is plotted on a
graph, the graph will form a curve of normal distribution.
The majority of people will fall in the middle of the graph
with a minority being at either extreme of the graph.
The same is true of normal and abnormal behaviour. If
someone's behaviour falls within the bottom or top 2.5%
(more than two standard deviations away from the mean)
then it is considered abnormal.
A good example of this is IQ. 65% of the population have an
IQ between 85 and 115 and the average IQ is 100. The
majority of the population (95%) have an IQ between 70
and 130. therefore those with an IQ below 70 fall into the
bottom 2.5% of the population and so could be considered
EVALUATION OF THE STATISTICAL
Does not tell us the difference between desirable
behaviour that is statistically infrequent and undesirable
behaviour that is infrequent.
A person may have a score above what is classed as
abnormal according to this definition e.g. an IQ of 71, and
so be classed as abnormal but they still may need help.
Some behaviours that would be classed as within the
normal range because so many people have them, such as
anxiety and depression, but are seen as abnormal in a
clinical sense. Kessler et al (1994) reported that 48% of
Americans have suffered with a mental disorder, in terms
of statistical frequency, this means that soon it will be 50%
meaning that it is normal to have a mental illness and it is
abnormal to be without a mental illness because they are
However it does give us a definite cut off point and one
which is objective, therefore taking away the subjectivity
of some of the other definitions of abnormality.…read more
SOCIAL NORMS DEFINITION
In every society there is a set of unwritten rules about the
behaviour that we expect in others and the behaviour we
don't expect. This sets our social norms, which decides
what behaviour is seen as normal, or moral.
If someone behaves in a way that does not conform to our
social norms we may feel anxious or threatened by them.
For example, we don't expect people to be talking to
themselves and may try to avoid them. However, if we
see that they have a mobile phone then this behaviour is
acceptable as it is a social norm to talk on the phone in
Some roles in society also come with what is considered to
be normal behaviour such as that doctors are expected to
be caring towards their patients.
However a number of factors need to be considered,
culture, situation/context, age, gender and historical
EVALUATION OF THE SOCIAL
This definition can lead to abuse of a persons rights based
on what society views as normal. In the past for example,
slaves who had an `irrational' desire to run away from
their masters were said to be suffering from
drapetomania. This would be an example of social control.
It is culturally biased, what may be acceptable in one
culture may not be in another.
Norms change over time so what one generation views as
abnormal the next generation may see as normal. For
example, 100 years ago single females who became
pregnant were put into mental asylums however now it is
accepted as part of our society.
The definition allows us to take several behaviours into
account which altogether may make us feel
uncomfortable, but which on their own would not be
classed as abnormal.…read more