Across consequential attributions of attitudes, ability, emotions, and morality, people make correspondent inferences. People infer stable personality characteristics from others' behavior, even when that behavior is caused by situational factors. We examined the structure of correspondent inferences and report the development and validation of an instrument measuring individual differences in this correspondence bias (a Neglect of External Demands scale, or "NED"). The NED is internally consistent and distinct from scales and measures of intelligence, cognitive ability, cognitive reflection, general decision making ability, preference for control, and attributional style. Individual differences in correspondence bias predict blaming people for harmful accidents, believing coerced confessions, correcting for job and task difficulty when making performance evaluations and incentive-compatible personnel selections, and separating market and fund performance when making incentive-compatible investments. Fortunately, the tendency to commit correspondence bias can be reduced. Making situational information easier to process debiases those most prone to correspondence bias.