The Pillars of Irrationality

1. Leaping to a decision.

Much irrationality results from simple laziness. “Jumping to a Conclusion” without taking the time to think things through. On the other hand, we all know people who analyze to excess.

When the cost of additional analysis exceeds the expected loss that may be avoided by such analysis (or the expected gain to be achieved thereby), it is time to stop.

2. Inadequate brain cache.

A human can hold only a small number of ideas in his mind at one time…… When faced with a complex decision, a decision maker must use at least elementary principles of decision theory if he is to arrive at an optimal result. Even the simple method outlined by Benjamin Franklin — writing down pros and cons in two columns on a sheet of paper — can greatly increase the probability of reaching a rational decision. More advanced techniques can be used to advantage in complex cases.

3. Self-deception.

This well-known pillar of irrationality can be explained by reference to the principle of cognitive dissonance — the mental conflict that occurs when cherished beliefs or assumptions are contradicted by new evidence. The tension aroused by this conflict is eased by various defensive mechanisms: denial, rejection, avoidance, and so forth.

The Pillars of Irrationality were suggested by a reading of Stuart Sutherland’s book Irrationality: Why We Don’t Think Straight (Rutgers University Press, 1995). Sutherland, a Professor of Psychology at the University of Sussex, reviews the mechanisms of irrationality in the light of recent psychological research.

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