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  1. Joachim I. Krueger

Published Online: 30 JAN 2010

DOI: 10.1002/9780470479216.corpsy0776

Corsini Encyclopedia of Psychology

Corsini Encyclopedia of Psychology

How to Cite

Krueger, J. I. 2010. Rationality. Corsini Encyclopedia of Psychology. 1–2.

Author Information

  1. Brown University

Publication History

  1. Published Online: 30 JAN 2010


With the study of human cognition comes the question of how well people can reason, and any answer requires standards with which observed cognitive performance can be compared. Cognition that does not meet these a priori standards is considered irrational. The Socratic philosophers held that rationality prevails unless disrupted by instincts, appetites, or emotions. They believed that only rational thought, but not momentary affect, can determine the best course of action. People are being irrational when they act against their own best interest, rationally defined. This conflict theory pervades Western philosophy and psychology. Of the topics for psychological research it has inspired, delay of gratification and temporal discounting are good examples. The theory holds that the rational mind takes the long-term view of the organism's well-being, whereas irrational forces demand rapid gratification. Although discounting of the future is not by itself irrational, its steep hyperbolic nature is. It is incoherent to prefer $50 now to $100 in a year, while at the same time preferring $100 in two years over $50 in a year (Ainslie, 2001).


  • cognition;
  • logical thinking;
  • rational thinking;
  • reasoning