Question

1. Causal Reasoning and Hindsight Bias Jennelle E. Yopchick (yopchick.j@husky.neu.edu) and Nancy S. Kim (n.kim@neu.edu) Northeastern University build causal path Prior Event Prior Event Prior Event LR-C Statement HR-NC Statement Prior Event Outcome Outcome Outcome Outcome Question Experiment 1a, cont’d Experiment 1b Experiment 2, cont’d • Hindsight bias (HB) is the phenomenon whereby the outcome of an event appears obvious only after the fact • Event information may be automatically assimilated with outcome information, making the outcome seem inevitable, ultimately resulting in HB (Fischhoff, 1975) • How does this assimilation process occur? • Previous work involving causal reasoning suggests that people spontaneously construct causal relations (Kunda, Miller, & Claire, 1990) and then use those causal relations to make inferences (Hastie, Schroeder, & Weber, 1990) • Drawing a causal link from an event to an outcome may make the outcome seem obvious and inevitable (Wasserman, Lempert, & Hastie, 1991) • Is causal reasoning one mechanism by which hindsight bias comes about? • Participants • 150 Northeastern undergraduates • Procedure • Foresight condition • Read about Judged the likelihood • an event of two possible outcomes • Baseline condition • Read about Read about the Judged the likelihood of • an event actual outcome two possible outcomes • of the event as if the actual outcome was not known • Four Plausibility/ Relevance conditions • Read about Read about the Read an • an event actual outcome additional statement • of the event • Judged the likelihood of two possible outcomes, • as if the actual outcome was not known • Hutu-Tutsi Scenario: • Event: In 1952, the Hutu tribe and the Tutsi tribe began a relentless battle. • Actual Outcome: In this particular battle, the Hutus won. • Additional Statement (between Ss) • High Plausibility Low Plausibility • High • Relevance • Low • Relevance • Judge Possible Outcomes: A Hutu Win; A Hutu Loss • Experiment 1a Results • ** p=.01 • Findings in Experiment 1a may have been due to the mere presence of the additional statement, from which conditional probabilities are inferred, rather than causal information per se (e.g., a higher conditional probability of winning with superior troops than when traveling west) • Stimuli • Formerly High-Relevance, now Non-Causal (HRNC) • During the battle, the Hutus showed superior discipline with their troops, but historians who have studied this particular battle unanimously agree that this did not actually affect the battle; rather, they believe that no particular factor led to the Hutu win – it is just something that happened by chance. • Formerly Low-Relevance, now Causal (LRC) • The Hutus began the day by traveling west, and found that they were facing away from the brilliant sunrise that effectively blinded the oncoming Tutsis, thereby becoming an important element in allowing the Hutus to win the battle. • Participants • 50 Northeastern undergraduates • Procedure • Identical to Experiment 1a • Experiment 1b Results Materials & Method Same as Experiment 1a, only the actual outcome was reversed (e.g., A Hutu Loss rather than A Hutu Win). Participants 75 Northeastern undergraduates Experiment 2 Results *p<.05 * Foresight Discussion • Causal reasoning is one mechanism by which hindsight bias comes about • When a causal link can be made from the event to the outcome, the outcome seems inevitable and HB results (Wasserman et al., 1991) • High Plausibility and High Relevance aid in the construction of a causal link from the event to the outcome • However, a priori plausible relevance itself is not necessary for HB to occur; rather, making a possible causal connection is • When the causal link can be more easily constructed to the alternative outcome, reverse HB will occur • Further research is needed to determine any mediating factors of the causal reasoning process of HB Logic • Increasing the ease of drawing this causal link should increase HB • We can accomplish this by adding a PLAUSIBLE and RELEVANT statement to the event (Wasserman et al., 1991) Hindsight bias arises through a causal link from the event to the outcome, rather than from the mere presence of the additional statement Plausible & Relevant Statement References ** Fischhoff, B. (1975). Hindsight  foresight: The effect of outcome knowledge on judgment under uncertainty. Journal of Experimental Psychology: Human Perception and Performance, 1, 288-299. Hastie, R., Schroeder, C., & Weber, R. (1990). Creating complex social conjunction categories from simple categories. Bulletin of the Psychonomic Society, 28, 242-247. Kunda, Z., Miller, D.T., & Claire, T. (1990). Combining social concepts: The role of causal reasoning. Cognitive Science, 14, 551-577. Ofir, C. & Mazursky, D. (1997). Does a surprising outcome reinforce or reverse the hindsight bias? Organizational Behavior and Human Decision Processes, 69, 51-57. Wasserman, D., Lempert, R.O., & Hastie, R. (1991). Hindsight and causality. Personality and Social Psychology Bulletin, 17, 30-35. Foresight (Exp.1a) Experiment 1a • Stimuli • Four event scenarios consisted of: • Event + Outcome + Additional Plausible/Relevant Statement • Plausibility = prior statistical likelihood of event occurring • Low Plausibility: Occurring 10% of the time in the past • High Plausibility: Occurring 90% of the time in the past • Relevance  pilot ratings confirmed the information was either highly relevant or irrelevant when trying to determine the actual outcome ** p=.01 (Exp.1a) Experiment 2 ** Reverse Hindsight Bias (Ofir & Makursky, 1997) “I never would have known it!” Causal Hypothesis of HB Predictions: If a causal link can be most easily drawn from the event to the alternative outcome, the actual outcome will be surprising (rather than obvious) and a reversal of likelihood estimates will occur Foresight