Overperceiving disease cues: the basic cognition of the behavioral immune system.

The behavioral immune system is designed to promote the detection and avoidance of potential sources of disease. Whereas previous studies of the behavioral immune system have provided insight into the types of heuristic cues used to identify disease carriers, the present research provides an understanding of the basic psychological processes involved in the detection of those cues. Across 4 studies, feeling vulnerable to disease, whether that feeling stemmed from dispositional tendencies or situational primes, facilitated a disease overperception bias--a tendency to overperceive people in the environment displaying heuristic disease cues. This disease overperception bias was observed in the outcomes of 2 cognitive processes: categorization and memory. When concerned about disease, participants set a lenient threshold for categorizing targets as displaying heuristic disease cues (e.g., obesity, old age). Additionally, concerns about disease led participants to set a lenient threshold for reporting on a recognition task that they had previously seen individuals displaying those disease cues. The present research provides insight into the basic cognitive mechanisms underlying the operation of the behavioral immune system.