Proceedings of the Annual Meeting of the Cognitive Science Society

Recent research has provided experimental support for a new ``Inferentialist'' theory of conditionals, challenging the Equation P(If A, C) = P(C | A) and theories that support it. The key evidence comes from probability judgments involving conditionals whose antecedent and consequent are relevant vs. irrelevant to each other. Expanding on recent experimental work, we argue that Inferentialism has difficulty explaining the data. However, theories that support The Equation theory are well-placed to account for the results once we recognize an independent phenomenon of pragmatic intrusion on probability judgment - in this case, participants' tendency to assign lower probability to conditionals that are pragmatically incoherent.