The similarity heuristic
Article first published online: 13 NOV 2009
Copyright © 2009 John Wiley & Sons, Ltd.
Journal of Behavioral Decision Making
Volume 24, Issue 1, pages 23–46, January 2011
How to Cite
Read, D. and Grushka-Cockayne, Y. (2011), The similarity heuristic. J. Behav. Decis. Making, 24: 23–46. doi: 10.1002/bdm.679
- Issue published online: 13 NOV 2009
- Article first published online: 13 NOV 2009
- heuristics and biases;
- fast-and-frugal heuristics;
- representative design;
- base-rate neglect;
- Bayesian inference
Decision makers often make snap judgments using fast-and-frugal decision rules called cognitive heuristics. Research into cognitive heuristics has been divided into two camps. One camp has emphasized the limitations and biases produced by the heuristics; another has focused on the accuracy of heuristics and their ecological validity. In this paper we investigate a heuristic proposed by the first camp, using the methods of the second. We investigate a subset of the representativeness heuristic we call the “similarity” heuristic, whereby decision makers who use it judge the likelihood that an instance is a member of one category rather than another by the degree to which it is similar to others in that category. We provide a mathematical model of the heuristic and test it experimentally in a trinomial environment. In this environment, the similarity heuristic turns out to be a reliable and accurate choice rule and both choice and response time data suggest it is also how choices are made. We conclude with a theoretical discussion of how our work fits in the broader “fast-and-frugal” heuristics program, and of the boundary conditions for the similarity heuristic. Copyright © 2009 John Wiley & Sons, Ltd.