Hindsight Bias: A Preregistered Replication Study Of Fischhoff (1975) With An Extension On Depressive Symptoms As Moderation.

Replicability and reproducibility are essential for scientific credibility, and both are promoted through open science practices and replications. In the area of mental health, there is low adherence to these practices. Moreover, there is low replicability of classic studies of human behavior, which makes it essential that studies in replication-extension models be better investigated. Fischhoff's (1975) seminal study gave rise to the “hindsight bias,” one of the most studied decision-making phenomena, described as a belief that the outcome of an event could have been predicted after it had already happened. However, this study has only one published replication. In addition, recent studies have revealed associations between hindsight bias and depressive symptoms under the memory design and with emotionally relevant outcomes. This association has not yet been investigated in a hypothetical design with neutral outcomes, such as Fischhoff's (1975) experiments. In the present study, we conducted a preregistered direct replication of Fischhoff’s Experiment 2 in the Brazilian population (n = 431) with extensions to investigate associations with sociodemographic variables and depressive symptoms. There was no difference (p < 0.05) between retrospective and prospective judgments in our sample. No significant association (p < 0.05) was found between hindsight bias and depressive symptoms or other sociodemographic variables. An exploratory analysis aggregating all comparisons obtained a small effect size for hindsight bias (d = 0.12; 95% CI [0.07; 0.37]). These results suggest a low replicability of Fischhoff's (1975) seminal experiment as well as the absence of associations with depressive symptoms when the phenomenon is obtained through a hypothetical design and with neutral outcomes.