Hindsight bias

Hindsight bias, sometimes called the I-knew-it-all-along effect, is the inclination to see events that have occurred as more predictable than they in fact were before they took place. Hindsight bias has been demonstrated experimentally in a variety of settings, including politics, games and medicine. In psychological experiments of hindsight bias, subjects also tend to remember their predictions of future events as having been stronger than they actually were, in those cases where those predictions turn out correct.

Prophecy that is recorded after the fact is an example of hindsight bias, given its own rubric, as vaticinium ex eventu.

One explanation of the bias is the availability heuristic; the event that did occur is more salient in one's mind than the possible outcomes that did not.

It has been shown that examining possible alternatives may reduce the effects of this bias.

Classic studies
Paul Lazarsfeld (1949): Lazarsfeld gave participants interpretive statements that seemed like common sense immediately after they were read, but in actuality the opposite was true.

Karl Teigen (1986): Teigen gave participants proverbs to evaluate. When participants were given the proverb "Fear is stronger than love", most students would rate it as true; when given its opposite ("Love is stronger than fear"), most would also rate that as true.

Phrases
The following common phrases are expressions for hindsight bias:


 * "With the wisdom of hindsight."
 * "Retrospective foresight."
 * "Hindsight is 20/20."
 * "We're all Monday morning quarterbacks."