Memory & Cognition

, Volume 30, Issue 2, pp 191–198 | Cite as

On the reality of the conjunction fallacy

  • Ashley Sides
  • Daniel Osherson
  • Nicolao Bonini
  • Riccardo Viale


Attributing higher “probability” to a sentence of formp-and-q, relative top, is a reasoning fallacy only if (1) the wordprobability carries its modern, technical meaning and (2) the sentencep is interpreted as a conjunct of the conjunctionp-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.


Noun Phrase Organize Sport Fallacy Rate Word Probability Conjunction Fallacy 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Psychonomic Society, Inc. 2002

Authors and Affiliations

  • Ashley Sides
    • 1
  • Daniel Osherson
    • 1
  • Nicolao Bonini
    • 1
  • Riccardo Viale
    • 1
  1. 1.Department of PsychologyRice UniversityHouston

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