title: On the reality of the conjunction fallacy.
abstract: Attributing higher "probability" to a sentence of form p-and-q, relative to p, is a reasoning fallacy only if (1) the word probability carries its modern, technical meaning and (2) the sentence p is interpreted as a conjunct of the conjunction p-and-q. Legitimate doubts arise about both conditions in classic demonstrations of the conjunction fallacy. We used betting paradigms and unambiguously conjunctive statements to reduce these sources of ambiguity about conjunctive reasoning. Despite the precautions, conjunction fallacies were as frequent under betting instructions as under standard probability instructions.
authors.affiliation: Rice University, Houston, Texas 77251-1892, USA.
authors.forename: Ashley
authors.initials: A
authors.lastname: Sides
authors.forename: Daniel
authors.initials: D
authors.lastname: Osherson
authors.forename: Nicolao
authors.initials: N
authors.lastname: Bonini
authors.forename: Riccardo
authors.initials: R
authors.lastname: Viale
mesh_terms: D003657:Decision Making; D006801:Humans; D011336:Probability