Intelligence and negation biases on the Conditional Inference Task: a dual-processes analysis

Nina Fay Attridge, Matthew Inglis

Research output: Contribution to journalArticlepeer-review


We examined a large set of conditional inference data compiled from several previous studies and asked three questions: How is normative performance related to intelligence? Does negative conclusion bias stem from Type 1 or Type 2 processing? Does implicit negation bias stem from Type 1 or Type 2 processing? Our analysis demonstrated that rejecting denial of the antecedent and affirmation of the consequent inferences was positively correlated with intelligence, while endorsing modus tollens inferences was not; that the occurrence of negative conclusion bias was related to the extent of Type 2 processing; and that the occurrence of implicit negation bias was not related to the extent of Type 2 processing. We conclude that negative conclusion bias is, at least in part, a product of Type 2 processing, while implicit negation bias is not.
Original languageEnglish
Pages (from-to)454-471
JournalThinking & Reasoning
Issue number4
Early online date19 Mar 2014
Publication statusPublished - 1 Apr 2014


  • Negative conclusion bias
  • Implicit negation bias
  • Affirmative premise bias
  • Conditional inference
  • Dual-processes

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