Talk:Subadditivity effect

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This text seems to be about some sort of heuristic rather than the subadditivity effect. --Spannerjam 07:30, 20 October 2013 (UTC)
The same mechanisms may underlie an effect of familiarity on probability judgment. More familiar events are more available. This is known as the availability heuristic. We find it easier to think of reasons why these events will and will not happen. In an experiment carried out by Fox and Levav (2000),[1] they asked students at Duke University which of two events was more likely to occur. The first one was "Duke men's basketball defeats UNC men's basketball at Duke's Cameron Indoor Stadium in January 1999," and the other one was "Duke men's fencing defeats UNC men's fencing at Duke's Cameron Card Gym in January 1999." The researchers postulated that since Duke students are much more familiar with basketball than with fencing, 75% of the students thought the basketball victory was more likely. Other students answered exactly the same questions, however, with Duke and UNC switched around. After the change, 44% of the students said that a UNC victory in basketball was more likely than a UNC victory in fencing. 44% plus 75% is 119%, which is larger than 100%, and only one such basketball game would be played. In this experiment, familiarity with basketball led subjects to think of the basketball event as more likely than the fencing event, regardless which basketball event was described.

References

  1. ^ Fox, C.R., & Levav, J. (2000). Familiarity bias and belief reversal in relative likelihood judgments. Organizational Behavior and Human Decision Processes, 82, 268–292.