Outcomes Affect Evaluations of Decision Quality: Replication and Extensions of Baron and Hershey's (1988) Outcome...

Outcome bias is the phenomenon whereby decisions which resulted in successful outcomes were rated more favorably than when the same decisions resulted in failures. We conducted a pre-registered replication and extension of Experiment 1 (original's: N = 20) from the classic Baron and Hershey (1988) with an online Amazon Mechanical Turk sample using CloudResearch (N = 692), switching from a within-participants design in the original experiment to a between-participants design. We tested outcome bias by measuring participants' ratings of the quality of decisions in medical scenarios. For the replication (pre-registered) part of the study, we successfully replicated signal and direction of the outcome bias (original: d_paired = 0.21 - 0.53; replication: d_independent = 0.77 [0.62, 0.93] to 1.1 [0.94, 1.26]), and even for participants who stated that outcomes should not be taken into consideration when evaluating decisions (d = 0.64 [0.21, 1.08]). For the extension part of the study, we found differences, dependent on outcome types, in evaluations of the perceived importance of considering the outcome, the perceived responsibility of decision-makers, and the perception that others would act similarly given the choice by outcome type. Materials, data, and code are available on Open Science Framework (OSF): https://osf.io/knjhu/.