When predicting the future, people tend to overestimate the intensity of their emotions, a phenomenon known as the impact bias. Design: In two studies, we examined the impact bias for health outcomes. In Study 1, participants were randomized to think about a negative health outcome in the future or one in the past. In Study 2, participants came to the laboratory and were asked to predict and report their emotions surrounding an actual health outcome (consuming an unhealthy food). Results: In both studies, an impact bias emerged. In Study 1, participants thinking about an outcome in the future estimated more negative emotion than those thinking about an outcome in the past. In Study 2, when facing an actual health outcome, participants anticipated more negative and positive emotion than they experienced. Impact biases were also associated with behavioral motivation - desire to change the outcome (Study 1) and increased preventive intentions (Study 2). Additional analyses revealed that regret was a particularly important emotion. Conclusion: Although research has highlighted an impact bias for severe health outcomes like disease, these studies provide evidence of an impact bias for health outcomes generally. They also suggest that the bias may have implications for behavior intentions.
Keywords: Impact bias; affective forecasting theory; health behavior; regret.