A Comparison of Hindsight Bias in Groups and Individuals: The Moderating Role of Plausibility


  • Dong-Won Choi,

    Corresponding author
    1. California State University, East Bay
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    • The authors made an equal contribution to the article, and the order of authorship was decided by a coin toss. The authors thank Peter Carnevale, Yimoon Choi, Reeshad Dalal, Ralph Evans, Sam Fraidin, Chu Kim-Prieto, Pat Laughlin, Jong Taek Lee, Hye Kyung Park, Seungho Shin, and Travis Sola for their helpful comments on an earlier draft of the article.

  • Incheol Choi

    Corresponding author
    1. Seoul National University
      Seoul, South Korea
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Dong-Won Choi, Department of Psychology, California State University, East Bay, 25800 Carlos Bee Boulevard, Hayward, CA 94542. E-mail: dong-won.choi@csueastbay.edu or to Incheol Choi, Department of Psychology, Seoul National University, Shilim-dong, Kwanak-gu, Seoul, South Korea. E-mail: ichoi@snu.ac.kr


We compared the magnitude of the hindsight bias in individuals and groups with the prediction that the plausibility of an outcome would affect the magnitude of the group–individual difference. We provided groups and individuals with outcomes of scientific studies, and asked them to predict the probability of those outcomes as if they did not know the given outcomes and to report their level of surprise at the outcomes. Overall, groups were more prone to hindsight bias than were individuals, but the group–individual difference was present only when the given outcomes were relatively implausible (Study 1). Moreover, this difference was not eliminated even when participants were asked to consider alternative outcomes (Study 2). Implications are discussed.