Representativeness Heuristic Definition
According to some social psychologists, human beings have the tendency to be cognitive misers—that is, to limit their use of mental resources when they need to make a quick decision or when the issue about which they must make a decision is unimportant to them. People have several strategies they can use to limit their use of mental resources; one such group of strategies is heuristics.
Heuristics are cognitive shortcuts or rules of thumb that are used when one must make a decision but lacks either ample time or the accurate information necessary to make the decision. Heuristics are advantageous in that they aid in quick decision making, but the use of heuristics can lead to inaccurate predictions. In general, heuristics are automatic cognitive processes; that is, people use them in decision-making situations without necessarily being aware that they are doing so.
One common heuristic is the representativeness heuristic, a rule of thumb used to determine whether a person or an event should be put into a certain category by judging how similar the person or event is to the prototypical person or event of that category. The prototypical person or event of a given category is the one that possesses the highest number of representative characteristics of that category; for example, the prototypical chair might have four legs, a seat, and some sort of back. If the person or event one is judging is similar to the prototype, then the person or event is likely to be placed in that category. If there is no similarity to the prototype, then the person or event may be judged as unlikely to be a member of the category. For example, in a freshman psychology course, Andrew meets Anne.
Andrew notices that Anne is petite, blonde, and very outgoing. Andrew tells his friend Jeff that he met Anne in class, and Jeff asks if Andrew met Anne the cheerleader or Anne the biology major. Andrew matches the petite, blonde, outgoing Anne he met to prototypes from the categories “cheerleader” and “biology major” and matches Anne to the “cheerleader” category because the prototypical cheerleader is petite, blonde, and outgoing. Because she fits the prototype of one category, Andrew may quickly categorize her and subsequently ignore information that would lead him to place Anne more accurately. Conversely, Andrew meets Heidi, who is tall, has short dark hair, and wears glasses. Because Heidi does not match the prototype of “cheerleader,” Andrew will likely assume that Heidi is not a cheerleader and may ignore evidence that indicates that she is a cheerleader.
Representativeness Heuristic and Decision Making
The representativeness heuristic can hinder accurate judgments of probability by emphasizing aspects of the event in question that are similar to the prototype or by masking other diagnostic information that demonstrates the event’s dissimilarity to the prototype. For example, in the previous Andrew and Anne scenario, Andrew assumes Anne is a cheerleader because she closely matches his prototype of that category. However, Andrew has ignored important information that might cause him to make a different judgment of Anne; in particular, he has ignored base rates, or the rate at which any one type of person or event occurs in the population at large. At any given university, the number of cheerleaders is typically quite small. On the other hand, the number of biology majors at any given university is much larger than the number of cheerleaders. If Andrew had used base rates instead of the representativeness heuristic as a basis for determining category membership, it is far more likely that he would determine that Anne is a biology major rather than a cheerleader. This example demonstrates the danger of relying on the representativeness heuristic when making decisions about category membership because the desire to use cognitive shortcuts may supersede the desire to seek accurate and complete information. Andrew’s dismissal of Heidi as a cheerleader is equally erroneous; it is just as likely that Heidi is a cheerleader as it is that Anne is a cheerleader, but because she does not appear to represent the cheerleader category, Andrew is unlikely to judge that she belongs to that category.
Representativeness Heuristic and Social Psychology
The representativeness heuristic is typically mentioned in the contexts of social cognition (the way people think about the people and situations with which they interact) and categorization (the process of classifying people and events based on their prominent attributes).
- Kahneman, D., & Tversky, A. (1972). Subjective probability: A judgment of representativeness. Cognitive Psychology, 3, 430-454.
- Kahneman, D., & Tversky, A. (1982). On the psychology of prediction. In D. Kahneman, P. Slovic, & A. Tversky (Eds.), Judgment under uncertainty: Heuristics and biases. New York: Cambridge University Press.
- Tversky, A., & Kahneman, D. (1993). Probabilistic reasoning. In A. I. Goldman (Ed.), Readings in philosophy and cognitive science. Cambridge: MIT Press.