Pessimism Bias

Pessimism bias is the tendency to exaggerate the likelihood that negative things will happen, the mirror image of the more commonly discussed optimism bias, in which people generally overestimate the likelihood of positive events and underestimate the likelihood of negative events happening to them. Optimism bias operates across demographic groups and shapes decision-making in areas including public health, policy and economics, with its strength varying with a person's mood, their desired outcome, and how much they know about themselves compared with others. Pessimism bias is the less common reversal of that pattern, and people experiencing depression show a particular susceptibility to it, exaggerating the likelihood that negative events will happen to them rather than underestimating it.