Proximity bias: Interactive effect of spatial distance and outcome valence on probability judgments

Across a range of decision contexts, we provide evidence of a novel proximity bias in probability judgments, whereby spatial distance and outcome valence systematically interact in determining probability judgments. Six hypothetical and incentive-compatible experiments (combined N = 4007) show that a positive outcome is estimated as more likely to occur when near than distant, whereas a negative outcome is estimated as less likely to occur when near than distant (studies 1-6). The proximity bias is explained by wishful thinking and thus perceptions of outcome desirability (study 3), and it does not manifest when an outcome is less relevant for the self, such as the case of outcomes with little consequence for the self (studies 4 and 5) or when estimating outcomes for others who are irrelevant to the self (study 6). Overall, the proximity bias we document deepens our understanding of the antecedents of probability judgments.

Automated summary

We have discovered a new proximity bias in probability judgments, where spatial distance and outcome valence interact in determining probability judgments. Through six hypothetical and incentive-compatible experiments (combined N = 4007), we found that positive outcomes are estimated as more likely when near and negative outcomes are estimated as less likely when near. This bias is explained by wishful thinking and perceptions of outcome desirability, and it does not manifest when the outcome is less relevant for the self or when estimating outcomes for others who are irrelevant to the self.