Psi man mascot

Defining Abnormal Behavior

When starting a discussion of abnormal behavior, students sometimes ask, "How can anybody tell what is abnormal, anyway?" There are several different criteria that can be used:

1. Statistical abnormality. A beha­vior might be judged abnormal if it is statistically unusual in a particular population.

2. Violation of socially-accepted standards. An abnormal behavior might be defined as one that goes against widely-accepted standards of behavior. One might be judged abnormal because of a failure to behave as recommended by one's family, church, employer, community, culture, or subculture.

3. Theoretical approaches. Abnor­mality can be defined by failure to develop along normal and expected developmental sequences. For example, adults usually develop the ability to suppress violence against other people. Someone who never develops that discipline might be called abnormal.

4. Subjective abnormality. Abnorm­al behavior can be defined by a person's feeling of abnormality, including feelings of anxiety, strange­ness, depression, losing touch with reality, or other experiences recog­nized as out of the ordinary and distressing.

5. Biological injury. Abnormal behavior can be defined or equated with abnormal biological processes such as disease or injury. Examples of such abnormalities are brain tumors, strokes, heart disease, diabetes, epilepsy, and genetic disorders.

What are limitations of each approach?

Each definition has its uses and its limitations. A statistical definition of abnormality is precise (one can collect data and show how common or uncommon a particular behavior is in a particular group) but it does not correspond well to what people call abnormal. Many rare behaviors, such as collecting old books, are not considered abnormal.

Violation of socially accepted standards is the usual standard of abnormality in authoritarian societies, where a rigid code of conduct may be laid down by rulers. Religious institutions may play the same role.

By this definition, a person is abnormal if violating the expectations and values of a community. For example, watching TV may be considered abnormal in the Amish culture, where modern conven­iences are avoided.

The main problem with defining abnormality as violations of social standards is that cultural standards change depending on the place and time. What is abnormal in one culture may be regarded as acceptable in a different culture. What is regarded as abnormal at one time may be regarded as normal several decades later.

What is wrong with using subjective discomfort as a criterion of abnormality?

Judging abnormality by subjective discomfort raises a different set of problems. Psychotic people, the most seriously disordered of all mental patients, often feel perfectly normal and suffer little distress, except for problems in living caused by a distorted view of reality.

Biological approaches to defining abnormal behavior are based on detecting a disease or disorder of the nervous system. Many of the classic psychiatric syndromes discussed in this chapter are now recognized as brain diseases involving abnormal levels of neurotransmitters, the chemicals that neurons use to communicate.

On the other hand, people tend to refer to any behavior they do not like as a disease or a disorder. The idea that alcoholism is a disease, for example, is controversial among psychology researchers, although it is a widely publicized idea.

Why are biological approaches to defining abnormal behavior gaining ground?

Biological approaches to defining abnor­mal behavior are gaining ground as bio­logical knowledge accumulates. Brain scans, analysis of neurotransmitters, and genetic analysis provide objective ways of identifying biological distur­bances.

What is the risk of overemphasizing biological factors?

Wakefield (1992) proposed that mental disorders should be called harmful dysfunctions. This label recognizes two things that are always present when abnormal behavior requires intervention:

–Some part of the biological/behav­ioral system of a person is not work­ing correctly (there is a dysfunction).

–The dysfunction threatens to harm somebody...either the person with the problem or other people, or both.

How did Wakefield propose to re-define "mental disorders"?

Wakefield notes that the concept of mental disorder is "on the boundary between biological facts and social values." Some biological problems are not judged harmful, because they do not contradict social values.

For example, a person who is tone deaf (unable to carry a tune) probably has a defect in part of the brain, or an under­developed module at any rate, but such a person is not dangerous to anybody, would not be judged as having a mental disorder, and would not be expected to seek therapy.

In the end, abnormal behavior is defined by the need to reduce harm. Behaviors that hurt people (either the person emitting the behavior or others affected by the behavior) are likely to be regarded as abnormal.

Some people require help that falls between the extremes of institutional­ization, on the one hand, and total independence, on the other. Many communities have day treatment centers and assisted living facilities for people with mild psychoses, adult autistics on the severe end of the spectrum, and others needing assistance with day to day living.

Szasz and the "Myth of Mental Illness"

In 1961, Thomas Szasz published a provocative book titled The Myth of Mental Illness arguing that society should abandon the effort to judge people sane or insane. Szasz (1961) claimed there was no real evidence for biological causes of mental illness (a claim easier to make in 1961 than now). He pointed to many cases in which people were labeled mentally ill as political acts in authoritarian societies.

Szasz believed that so-called mentally ill people should have the same rights and responsibilities as everybody else. His position was not simply lenient and forgiving, however.

He felt that in exchange for having the same freedom as every other citizen, an "insane" person should also have the same responsi­bilities as every other citizen and should not be exempt­ed from moral or legal blame for deviant behavior.

Therefore, Szasz was against the insanity defense in our legal system, with its implication that people judged insane should be excused from punishment for illegal behavior. Instead (Szasz argued) such an individual should be treated like everybody else.

What was the famous theoretical position of Thomas Szasz? In what sense was Szasz's position "not simply lenient and forgiving"?

Szasz's position was very radical when he first put it forward, but many people agreed with the essence of his argument about freedom and responsibility. Most could see that political repression around the world was commonly disguised as a response to mental illness.

Eventually, the laws in the United States changed to resemble Szasz's recom­mendations. Many states passed legislation making it illegal to put people in mental hospitals against their will, unless they presented a danger to others.

Szasz's political position against locking people up for deviant behavior prevailed. However, almost no professional in the mental health professions agreed that disordered minds were a "myth."

For example, Kety (1974), responding to Szasz's position, collected all the evidence for genetic influences on schizophrenia. He concluded, "If schizophrenia is a myth, it is a myth with a strong genetic component" (p.961).

How did Kety respond to Szasz's statements about the "myth of mental illness"?

As already noted, biological explanations of abnormal behaviors are actually getting more common, as knowledge about the brain increases. Brain scanning technologies, genetic analysis, and knowledge about neuro­transmitters have all led to an increasingly biological emphasis in the diagnosis and treatment of psychiatric disorders.

Szasz might respond that an identifiable biological illness is just that: a biological illness. Mental illness is still a myth because minds do not get sick.

What is labeled mental illness is behavior. Psychiatric diagnoses are used when behavior is harmful to others or disapproved by society.

We do not label people with brain diseases mentally ill if they act normally. So mental illness should be recognized as a label conveying political or moral judgment, not a medical judgment.


Concern for the legal rights of people committed to mental institutions led to a radical shift of public policy in America. New laws made it much harder to keep people in mental institutions involuntarily.

This became known as the deinstitu­tionalization movement. "Deinstitution­alization" refers to the release of patients formerly housed in mental hospitals to the outside world.

There were several reasons why the deinstitutionalization movement spread through the United States and Canada and many other countries. Scholars like Thomas Szasz argued that mental illness was unjust if a person had not proven dangerous to others. Govern­ment panels projected excessive public expenditures if the populations of mental hospitals continued to grow.

Critics pointed to evidence that staying in a mental hospital could do more harm than good. New psychiatric drugs allowed many people to live success­fully outside hospitals, especially if they received supervised care.

What was the deinstitutionalization movement, and what were some of the factors that caused it?

New laws declared that people could not be hospitalized against their will unless they were an obvious threat to others. Suddenly many former mental patients were free to leave the hospital, for better or for worse, until they were proven dangerous. If they managed to live on their own without getting into trouble with the law, they could stay free.

Unfortunately, many people released into urban areas could not find jobs or housing. The result was a sudden increase in the number of homeless people in the 1970s and 1980s.

Mental patients seemed to exchange one form of misery for another. Many of the former mental patients got into trouble and ended up being incarcerated again, this time in jails instead of mental hospitals.

Northwestern University psychiatry professor Linda Teplin studied this problem for decades. She found, for example, that inmates of the Cook County jail in Chicago had rates of mental illness two to four times higher than the general population (Teplin, 1984).

What problems did deinstitutionalization create?

Teplin found that 9 percent of male in­mates and 18.5 percent of females had serious psychiatric disorders like psy­chosis. She said the percentage of female inmates with mental disorders was higher because "only the most messed-up women end up in jail, the drug users and prostitutes," while criminal activity was more common among men.

A report released in 1990 declared that the Los Angeles Country Jail, with an estimated 3,600 inmates who were seriously mental ill. This qualified the Los Angeles County Jail as the largest "de facto mental hospital" in the United States.

What was the largest "de facto mental hospital" in the United States, in 1990?

A 2012 survey showed that "the number of people suffering from serious mental illness in jails and prisons is now 10 times the number receiving treatment in state psychiatric hospitals." There were 350,000 in prisons in the U.S. at the time of the survey, compared to 35,000 in mental hospitals (Mahoney and Thompson (2015).

"It is well known that US prisons and jails have taken on the role of mental health facilities," wrote Janie Fellner, a senior advisor at Human Rights Watch, in 2015. The alternatives, community-based outpatient and residential programs, were often unavailable or too expensive.

Mahoney and Thompson (2015) pointed to laws that aggravated the situation. For example, in the U.S., Medicaid (the free insurance for poor people) stops if a person is arrested. Then they no longer have access to doctors, medicines, or a means to pay for them. "Their mental health soon deteriorates and they frequently wind up back in jail."

Fellner (2015) charged that prison officers received minimal training for dealing with mentally disturbed people, except to restrain them by force. Complaints of unnecessary, excessive, and even malicious force against mentally disturbed inmates were common. Behaviors like banging on doors or urinating on cell floors might be severely punished.

Fellner (2016) offered no easy solutions except a plea for compassion, tolerance, and training. Prison staff should know how to use nonviolent means of dealing with problems before resorting to force. She also pointed out that decrim­inalizing "minor symptoms of mental illness" such as "homelessness, poverty, and substance abuse" would help keep people out of the prison system.


Cadoret, R. J., O'Gorman, T. W., Troughton, E. & Haywood, E. (1985) Alcoholism and antisocial personality. Archives of General Psychiatry, 42, 161-170.

Fellner, J. (2015) Callous and cruel. Human Rights Watch. Retrieved from:

Fellner, J. (2016, May 9) How to keep mentally ill from getting behind bars. New York Times. Retrieved from:

Fischer, P. J. & Breakey, W. R. (1991). The epidemiology of alcohol, drug, and mental disorders among homeless persons. American Psychologist, 46, 1115-1128.

Kety, S. S. (1974) From rationalization to reason. American Journal of Psychiatry, 131, 957-963.

Mahoney, D. & Thompson, J. (2015, June 26) The Hill. Retrieved from:

Szasz, T. (1961) The Myth of Mental Illness: Foundations of a Theory of Personal Conduct. New York: Hoeber-Harper.

Teplin, L. A. (1984). Criminalizing mental disorder. American Psychologist, 39, 794-803.

Wakefield, J. C. (1992). The concept of mental disorder: On the boundary between biological facts and social values. American Psychologist, 47, 373-388.

Write to Dr. Dewey at

Don't see what you need? Psych Web has over 1,000 pages, so it may be elsewhere on the site. Do a site-specific Google search using the box below.