Criteria you might use to label behavior as “abnormal”.

1. Distress or disability. An individual experiences personal distress or disabled functioning, which produces a risk of physical or psychological deterioration or loss of freedom of action. For example, a man who cannot leave his home without weeping would be unable to pursue ordinary life goals.

2. Maladaptiveness. An individual acts in ways that hinder goals, do not contribute to personal well- being, or interfere strongly with the goals of others and the need of society. Someone who is drinking so heavily that she cannot hold down a job or who is endangering others through her intoxication is displaying maladaptive behavior.

3. Irrationality. An individual acts or talks in ways that are irrational or incomprehensible to others. A man who responds to voices that do not exist in objective reality is behaving irrationally.

4. Unpredictability. An individual behaves unpredictably or erratically from situation to situation, as if experiencing a loss of control. A child who smashes his fist through a window for no apparent reason displays unpredictability.

5. Unconventionality and statistical rarity. An individual behaves in ways that are statistically rare and that violate social standards of what is acceptable or desirable. Just being statistically unusual, however, does not lead to a psychological judgment of abnormality. For example, possessing genius-level intelligence is extremely rare, but it is also considered desirable. Conversely, having extremely low intelligence is also rare but is considered undesirable; thus it has often been labeled abnormal.

6. Observer discomfort. An individual creates discomfort in others by making them feel threatened or distressed in some way. A woman walking down the middle of the sidewalk, having a loud conversation with herself, creates observer discomfort in other pedestrians trying to avoid her.

7. Violation of moral and ideal standards. An individual violates expectations for how one ought to behave with respect to societal norms. Thus, if people generally think it is important to provide care to one’s offspring, parents who abandoned their children might be considered abnormal.

Gerrig, R.J. (2012). Psychology and Life. (20th edition). (pp. 386-387) Pearson