title: Is probabilistic evidence a source of knowledge?
abstract: We report a series of experiments examining whether people ascribe knowledge for true beliefs based on probabilistic evidence. Participants were less likely to ascribe knowledge for beliefs based on probabilistic evidence than for beliefs based on perceptual evidence (Experiments 1 and 2A) or testimony providing causal information (Experiment 2B). Denial of knowledge for beliefs based on probabilistic evidence did not arise because participants viewed such beliefs as unjustified, nor because such beliefs leave open the possibility of error. These findings rule out traditional philosophical accounts for why probabilistic evidence does not produce knowledge. The experiments instead suggest that people deny knowledge because they distrust drawing conclusions about an individual based on reasoning about the population to which it belongs, a tendency previously identified by "judgment and decision making" researchers. Consistent with this, participants were more willing to ascribe knowledge for beliefs based on probabilistic evidence that is specific to a particular case (Experiments 3A and 3B).
authors.affiliation: Department of Psychology, University of Waterloo.
authors.forename: Ori
authors.initials: O
authors.lastname: Friedman
authors.affiliation: Department of Philosophy, University of Waterloo.
authors.forename: John
authors.initials: J
authors.lastname: Turri
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003657:Decision Making; D005260:Female; D006801:Humans; D007600:Judgment; D019359:Knowledge; D008297:Male; D008875:Middle Aged; D011336:Probability; D056345:Theory of Mind; D055815:Young Adult
keywords: Folk epistemology; Knowledge; Probabilistic evidence; Theory of mind