Pessimism Bias
The tendency to overestimate the likelihood and severity of negative outcomes, particularly prominent in people experiencing anxiety or depression.
Origin
The concept emerged as the counterpart to optimism bias within cognitive psychology. Aaron Beck, the American psychiatrist who founded cognitive therapy, described the "negative cognitive triad" in 1967 — depressed individuals holding pessimistic views of themselves, the world, and the future. Lauren Alloy and Lyn Abramson's 1979 "depressive realism" hypothesis added nuance, showing that depressed people may sometimes be more accurate than their optimistically biased peers. Neil Weinstein at Rutgers formalized the framework in 1980 with his work on unrealistic optimism.
Everyday Use
Before a job interview, you're convinced you'll blow it, even though your track record says otherwise. Pessimism bias is the flip side of optimism bias — instead of assuming things will work out, you weight the worst-case scenario too heavily. It can be protective (preparing for the worst), but it can also paralyze decision-making and fuel chronic anxiety.