Irrationality


 * For irrationality as it relates to numbers, see irrational number.

Irrationality is talking or acting without regard of rationality. Usually pejorative, the term is used to describe emotion-driven thinking and actions which are, or appear to be, less useful or logical than the rational alternatives. There is a clear tendency to view our own thoughts, words, and actions as rational and to see those who disagree as irrational.

Types of behavior which are often described as irrational include:
 * fads and fashions
 * crowd behavior
 * offense or anger at a situation that has not yet occurred
 * unrealistic expectations
 * belief in logical fallacies
 * falling victim to confidence tricks
 * belief in the supernatural without evidence
 * stock-market bubbles
 * types driven by mental illness, including dwelling on obsessions or acting out compulsions driven by obsessive-compulsive disorder, or dwelling on a depressed mental state brought about by major depressive disorder.

Why does irrational behavior occur?
The study of irrational behavior is of interest in fields such as psychology, cognitive science, economics, game theory, and evolutionary psychology, as well as of practical interest to the practitioners of advertising and proda.

Theories of irrational behavior include:
 * people's actual interests differ from what they believe to be their interests
 * mechanisms that have evolved to give optimal behavior in normal conditions lead to irrational behavior in abnormal conditions
 * people's interests are controlled by emotional mechanisms, and "rationality" as such is a meaningless concept
 * apparently irrational decisions are actually optimal, but made unconsciously on the basis of "hidden" interests that are not known to the conscious mind
 * Some people find themselves in this condition by living "double" lives. They try put on one "mask" for one group of people and another for a different group of people. Many will become confused as to which they really are or which they wish to become.

Factors which affect rational behavior include:
 * stress, which in turn may be emotional or physical
 * the introduction of a new or unique situation