Irrationalities

Irrationality is cognition, thinking, talking or acting without inclusion of rationality. It is more specifically described as an action or opinion given through inadequate use of reason, or through emotional distress or cognitive deficiency. The term is used, usually pejoratively, to describe thinking and actions that are, or appear to be, less useful, or more illogical than other more rational alternatives.

Irrational behaviors of individuals include taking offense or becoming angry about a situation that has not yet occurred, expressing emotions exaggeratedly (such as crying hysterically), maintaining unrealistic expectations, engaging in irresponsible conduct such as problem intoxication, disorganization, or extravagance, and falling victim to confidence tricks. People with a mental illness like schizophrenia may exhibit irrational paranoia.

These more contemporary "normative conceptions" of what constitutes a manifestation of irrationality are difficult to demonstrate empirically because it is not clear by whose standards we are to judge the behavior rational or irrational. Irrationality, historically speaking, is an outcome of the ancient Greek separation of rationality (logos) from emotion and sensuality as the sources of "false" assumptions and statements.

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 propaganda.

Theories of irrational behavior include:

Factors which affect rational behavior include:

Irrationality is not always viewed as a negative. Dada Surrealist art movements embraced irrationality as a means to "reject reason and logic". André Breton, for example, argued for a rejection of pure logic and reason which are seen as responsible for many contemporary social problems.

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