title: Exemplars in the mist: the cognitive substrate of the representativeness heuristic.
abstract: The idea that people often make probability judgments by a heuristic short-cut, the representativeness heuristic, has been widely influential, but also criticized for being vague. The empirical trademark of the heuristic is characteristic deviations between normative probabilities and judgments (e.g., the conjunction fallacy, base-rate neglect). In this article the authors contrast two hypotheses concerning the cognitive substrate of the representativeness heuristic, the prototype hypothesis (Kahneman & Frederick, 2002) and the exemplar hypothesis (Juslin & Persson, 2002), in a task especially designed to elicit representativeness effects. Computational modelling and an experiment reveal that representativeness effects are evident early in training and persist longer in a more complex task environment and that the data are best accounted for by a model implementing the exemplar hypothesis.
authors.affiliation: Department of Psychology, Uppsala University, Uppsala, Sweden. hakan.nilsson@psyk.uu.se
authors.forename: Håkan
authors.initials: H
authors.lastname: Nilsson
authors.forename: Peter
authors.initials: P
authors.lastname: Juslin
authors.forename: Henrik
authors.initials: H
authors.lastname: Olsson
mesh_terms: D000328:Adult; D003071:Cognition / Q000502:physiology*; D003198:Computer Simulation; D003657:Decision Making / Q000502:physiology; D005260:Female; D006801:Humans; D007600:Judgment / Q000502:physiology*; D008297:Male; D008960:Models, Psychological; D011237:Predictive Value of Tests; D011336:Probability; D011337:Probability Learning; D013334:Students / Q000523:psychology; D013647:Task Performance and Analysis