MURAL - Maynooth University Research Archive Library

    Surprising rationality in probability judgment: Assessing two competing models

    Costello, Fintan and Watts, Paul and Fisher, Christopher (2018) Surprising rationality in probability judgment: Assessing two competing models. Cognition, 170. pp. 280-297. ISSN 0010-0277

    Download (958kB) | Preview

    Share your research

    Twitter Facebook LinkedIn GooglePlus Email more...

    Add this article to your Mendeley library


    We describe 4 experiments testing contrasting predictions of two recent models of probability judgment: the quantum probability model (Busemeyer, Pothos, Franco, & Trueblood, 2011) and the probability theory plus noise model (Costello & Watts, 2014, 2016a). Both models assume that people estimate probability using formal processes that follow or subsume standard probability theory. One set of predictions concerned agreement between people’s probability estimates and standard probability theory identities. The quantum probability model predicts people’s estimates should agree with one set of identities, while the probability theory plus noise model predicts a specific pattern of violation of those identities. Experimental results show the specific pattern of violation predicted by the probability theory plus noise model. Another set of predictions concerned the conjunction fallacy, which occurs when people judge the probability of a conjunction P ( ) A B ∧ to be greater than one or other constituent probabilities P (A) or P ( ) B , contrary to the requirements of probability theory. In cases where A causes B, the quantum probability model predicts that the conjunction fallacy should only occur for constituent B and not for constituent A: the noise model predicts that the fallacy should occur for both A and B. Experimental results show that the fallacy occurs equally for both, contrary to the quantum probability prediction. These results suggest that people’s probability estimates do not follow quantum probability theory. These results support the idea that people estimate probabilities using mechanisms that follow standard probability theory but are subject to random noise

    Item Type: Article
    Keywords: Probability; Quantum theory; Conjunction fallacy;
    Academic Unit: Faculty of Science and Engineering > Theoretical Physics
    Item ID: 13097
    Identification Number:
    Depositing User: Paul Watts
    Date Deposited: 23 Jun 2020 15:28
    Journal or Publication Title: Cognition
    Publisher: Elsevier
    Refereed: Yes

    Repository Staff Only(login required)

    View Item Item control page


    Downloads per month over past year