by Saul McLeod published 2008
Abnormal psychology is a division of psychology that studies people who are "abnormal" or "atypical" compared to the members of a given society.
There is evidence that some psychological disorders are more common than was previously thought.
Depending on how data are gathered and how diagnoses are made, as many as 27% of some population groups may be suffering from depression at any one time (NIMH, 2001; data for older adults).
There are many ways that abnormality can be defined. For example:
Under this definition of abnormality, a person's trait, thinking or
behavior is classified as abnormal if it is rare or statistically unusual. With this definition it is necessary to be clear about how rare a trait or
behavior needs to be before we class it as abnormal
For instance one may say that an individual who has an IQ below or above the average level of IQ in society is abnormal.
However this definition obviously has limitations, it fails to recognize the desirability of the particular behavior.
Going back to the example, someone who has an IQ level above the normal average wouldn't necessarily be seen as abnormal, rather on the contrary they would be highly regarded for their intelligence.
This definition also implies that the presence of abnormal behavior in people should be rare or statistically unusual, which is not the case. Instead, any specific abnormal behavior may be unusual, but it is not unusual for people to exhibit some form of prolonged abnormal behavior at some point in their lives.
Limitation: However, this definition fails to distinguish between desirable and undesirable behavior. Statistically speaking, many very gifted individuals could be classified as ‘abnormal’ using this definition. The use of the term ‘abnormal’ in this context would not be appropriate.
Many rare behaviors or characteristics (e.g. left handedness) have no bearing on normality or abnormality. Some characteristics are regarded as abnormal even though they are quite frequent. Depression may affect 27% of elderly people (NIMH, 2001). This would make it common but that does not mean it isn’t a problem
Violation of Social Norms
Under this definition, a person's thinking or behavior is classified as abnormal if it violates the (unwritten) rules about what is expected or acceptable behavior in a particular social group. Their behavior may be incomprehensible to others or make others feel threatened or uncomfortable. Social behavior varies markedly when different cultures are compared.
For example, it is common in Southern Europe to stand much closer to strangers than in the UK. Voice pitch and volume, touching, direction of gaze and acceptable subjects for discussion have all been found to vary between cultures.
With this definition, it is necessary to consider: (i) The degree to which a norm is violated, the importance of that norm and the value attached by the social group to different sorts of violation. (ii) E.g. is the violation rude, eccentric, abnormal or criminal?
Limitation: Social norms change over time. behavior that was once seen as abnormal may, given time, become acceptable and vice versa. For example drink driving was once considered acceptable but is now seen as socially unacceptable whereas homosexuality has gone the other way. Until 1980 homosexuality was considered a psychological disorder by the World Health
Organization (WHO) but today is considered acceptable.
Failure to Function Adequately
Under this definition, a person is considered abnormal if they are unable to cope with the demands of everyday life. They may be unable to perform the behaviors necessary for day-to-day living e.g. self-care, hold down a job, interact meaningfully with others, make themselves understood etc.
Rosenhan & Seligman (1989) suggest
the following characteristics that define failure to function
o Maladaptiveness (danger to self)
o Vividness & unconventionality (stands out)
o Unpredictably & loss of control
o Causes observer discomfort
o Violates moral/social standards
One limitation of this definition is that apparently abnormal
behavior may actually be helpful, function and adaptive for the individual. For example, a person who has the obsessive-compulsive disorder of hand-washing may find that the
him cheerful, happy and better able to cope with his day.
Many people engage in behavior that is maladaptive/harmful or threatening to self, but we don’t class them as abnormal
Smoking, drinking alcohol
Deviation from ideal mental health
Under this definition, rather than defining what is abnormal, we define what is normal/ideal and anything that deviates from this is regarded as abnormal. This requires us to decide on the characteristics we consider necessary to mental health.
Psychologists vary, but usual characteristics include:
o Positive view of the self
o Capability for growth and development
o Autonomy and independence
o Accurate perception of reality
o Positive friendships and relationships
o Environmental mastery able to meet the varying demands of day-to-day situations
Limitation: It is practically impossible for any individual to achieve all of the ideal characteristics all of the time. For example, a person might not be the ‘master of his environment’ but be happy with his situation. The absence of this criterion of ideal mental health hardly indicates he is suffering from a mental disorder.
Ethnocentric: Most definitions of psychological abnormality are devised by white, middle class men. It has been suggested that this may lead to disproportionate numbers of people from certain groups being diagnosed as "abnormal."
For example, in the UK, depression is more commonly identified in women, and black people are more likely than their white counterparts to be diagnosed with schizophrenia. Similarly, working class people are more likely to be diagnosed with a mental illness than those from non manual backgrounds.
National Institute of Mental Health. (2001). Depression research at the National Institute of Mental Health. Retrieved from http://www.nimh.nih.gov/health/publications/depression/complete-index.shtml.
Rosenhan, D.L. and Seligman, M.E.P. (1989). Abnormal Psychology. Second edition. New York: W.W. Norton.
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Listen to a MIT undergraduate lecture on Defining Mental Illness.
Listen to a MIT undergraduate lecture on Causing Mental Illness.
Mass Shootings and Mental Illness
BBC Radio 4 Broadcast on why some people have schizophrenia and others don't.
BBC Radio 4 Broadcast on David Rosenhan's Pseudo-Patient Study.
How to cite this article:
McLeod, S. A. (2008). . Retrieved , from