It is not the case that if you understand a conditional you know how to negate it

Abstract

We report the results of an experiment to test the cognitive processes underlying inferences from negated conditionals, e.g., ‘it is not the case that if A then B’. The results show that people endorse not only the conditional conclusion ‘if A then not B’ but also ‘if not A then B’. We discuss the implications of the results for competing explanations of reasoning about negated conditionals.

Keywords:

• Conditionals
• Negation
• Reasoning

Acknowledgements

The research was carried out while Orlando Espino was a visiting academic at Trinity College Dublin in 2008 supported by a grant from the Government of the Canary Islands. We thank Phil Johnson-Laird, Sunny Khemlani, and Linden Ball for helpful comments.