Abstract. We conducted a systematic review of longitudinal theory of mind (ToM) studies, focusing on the precursors to and functional outcomes of ToM in typically-developing samples. Our search yielded 87 longitudinal studies, all of which involved children and adolescents. Early attention skills, executive function development, and the use of language are precursors to ToM development. Additionally, quality interaction with parents and older siblings can foster early improvements in ToM. Healthy ToM development improves social relationships with peers and produces greater desire to engage in prosocial behaviors. However, victimized individuals with highly-developed ToM may engage in increased aggression. Future longitudinal research is needed to investigate the functional outcomes resulting from ToM changes in adulthood.

Nonprobative but related photos can increase the perceived truth value of statements relative to when no photo is presented (truthiness). In two experiments, we tested whether truthiness generalizes to credibility judgments in a forensic context. Participants read short vignettes in which a witness viewed an offence. The vignettes were presented with or without a nonprobative, but related photo. In both experiments, participants gave higher witness credibility ratings to photo-present vignettes compared to photo-absent vignettes. In Experiment 2, half the vignettes included additional nonprobative information in the form of text. We replicated the photo presence effect in Experiment 2, but the nonprobative text did not significantly alter witness credibility. The results suggest that nonprobative photos can increase the perceived credibility of witnesses in legal contexts.

Hindsight bias occurs when outcome information distorts people’s memories of past beliefs or exaggerates perceptions of outcomes’ foreseeability or inevitability. We investigated whether community and university participants in Canada and the U.S. exhibited hindsight bias for COVID-19. In Experiment 1 (N = 175), participants made original judgments about COVID-19 outcomes. Two months later, participants learned outcome information and recalled their original judgments (memory design). They also rated the foreseeability and inevitability of COVID-19. In Experiment 2 (N = 754), we used a hypothetical design. Participants learned outcome information before estimating how naïve peers would have responded 2 months earlier. Participants exhibited hindsight bias in memory and hypothetical estimations. However, they rated COVID-19 as unforeseeable and avoidable and generally did not exhibit differences in foreseeability and inevitability ratings across the two timepoints. Thus, hindsight bias for COVID-19 differs across memory distortions, foreseeability, and inevitability and extends to hypothetical judgments.

The sunk-cost effect (SCE) is the tendency to continue investing in something that is not working out because of previous investments that cannot be recovered. In three experiments, we examine the SCE when continued investment violates the ethic of care by harming others. In Experiment 1, the SCE was smaller if the sunk-cost decision resulted in harmful consequences towards others (an interaction between sunk cost and the ethic of care). In Experiment 2, participants considered vignettes from their own or another person's perspective. We observed an interpersonal SCEpeople showed the SCE when taking the perspective of others. We did not replicate the interaction found in Experiment 1. In Experiment 3, we used statistically more powerful analyses -Bayesian sequential hypothesis testingto examine the interaction between sunk cost and the ethic of care. We found evidence in favor of the interaction; the SCE was smaller if the sunk-cost decision harmed others. We suggest that violating one's ethic of care de-biases decision-making by overshadowing sunk costs. These findings may help explain decision-making in real-world situations involving large investments.