The contagion heuristic is a psychological heuristic leading people to avoid contact with people or objects viewed as "contaminated" by previous contact with someone or something viewed as bad—or, less often, to seek contact with objects that have been in contact with people or things considered good. For example, we tend to view food that has touched the ground as contaminated by the ground, and therefore unfit to eat, or we view a person who has touched a diseased person as likely to carry the disease (regardless of the actual contagiousness of the disease).
The contagion heuristic includes "magical thinking", such as viewing a sweater worn by Adolf Hitler as bearing his negative essence and capable of transmitting it to another wearer. The perception of essence-transfer extends to rituals to purify items viewed as spiritually contaminated, such as having Mother Teresa wear Hitler's sweater to counteract his essence.
Inattention. Inattention is like the Freudian defense mechanism of denial, except that it may be much more passive. We simply do not think much about the interpersonal history of most objects we deal with. When we receive change in the store, we do not think of the long string of humans, no doubt some unsavory, who handled it previously; likewise for the interpersonal history of a public bathroom doorknob or a seat on a train. The domains of inattention vary across individuals and across cultures. For example, the contamination produced by the bottoms of shoes bringing outside filth into the home is salient for most Japanese, but not attended to by most Americans.
Ritual rules. Typically in religious systems, problems of contagion may be handled by establishing rituals to decontaminate and setting limits on the range of contamination. Such rules seem most prevalent in Judaism and Hinduism. A particularly clear example of a ritual boundary is the 1/60th rule of Kashrut, relating to contamination of kosher foods by non-kosher entities (Nemeroff & Rozin, 1992). According to this rule, if contamination occurs by accident and the contaminant is less than 1/60th of the total volume of the contaminated entity, the food remains kosher.
- Law of contagion
- List of topics characterized as pseudoscience
- Magical thinking
- Projective identification
- Sacred contagion
- Sympathetic magic
- Heuristics and Biases: The Psychology of Intuitive Judgement by Daniel Kahneman, p. 212.
- Heuristics and Biases - The Psychology of Intuitive Judgment Edited by THOMAS GILOVICH, Cornell University DALE GRIFFIN, Stanford University DANIEL KAHNEMAN, Princeton University (page 213)
- Nemeroff, C., & Rozin, P. (2000). "The makings of the magical mind: The nature of function of sympathetic magic." In K. S. Rosengren, C. N. Johnson, & P. L. Harris (Eds.), Imagining the impossible: Magical, scientific, and religious thinking in children (pp. 1-34). New York: Cambridge University Press.