Paper on reasoning about facts and possibilities out in Cognitive Science

I have a new paper out in Cognitive Science with Ruth Byrne and Phil Johnson-Laird. We developed a theory about “sentential reasoning”, which is the sort of reasoning that occurs when you think about sentences that are connected by words such as “and”, “or”, or “if.” Cognitive theories have yet to explain the process by which people reason about sentences that concern facts, and possibilities, and so we built a theory around the idea that humans reason about sentences by simulating the world around them as sets of possibilities. We designed a computational model and applied it to explain some recent data on sentential reasoning.


The paper is available for download here, and here’s the abstract:


This article presents a fundamental advance in the theory of mental models as an explanation of reasoning about facts, possibilities, and probabilities. It postulates that the meanings of compound assertions,
such as conditionals (if) and disjunctions (or), unlike those in logic, refer to conjunctions of epistemic possibilities that hold in default of information to the contrary. Various factors such as general knowledge can modulate these interpretations. New information can always override sentential inferences; that is, reasoning in daily life is defeasible (or nonmonotonic). The theory is a dual process one: It distinguishes
between intuitive inferences (based on system 1) and deliberative inferences (based on system 2). The article describes a computer implementation of the theory, including its two systems of reasoning, and it shows how the program simulates crucial predictions that evidence corroborates. It concludes with a discussion of how the theory contrasts with those based on logic or on probabilities.


If you want to check out any of the computational modeling code or the data for it, they’re available via OSF.