The Counterfactual Detective: People Think About What Could Have Been to Uncover Past Events

We reveal a way that people use counterfactual thinking: They use it to infer motives and solve mysteries about what happened in the unseen past. In three preregistered experiments, participants (total N = 1,242) were asked to determine which of two competitors in a contest had sabotaged a third competitor. Participants often succeeded in identifying the culprit when counterfactual reasoning could be used to judge whether each suspect profited from the sabotage. Participants had more difficulty, though, when the mystery required using counterfactuals to judge how much each suspect profited. These findings show that people can use counterfactual reasoning to infer others’ motives and to determine who was most likely to have produced past events. But they find this easier when counterfactuals support binary judgments rather than graded ones. Besides revealing a way that people use counterfactual reasoning, the findings are informative about how people learn about the unobserved past.