The authors outline a theory of conditionals of the form If A then C and If A then possibly C. The 2 sorts of conditional have separate core meanings that refer to sets of possibilities. Knowledge, pragmatics, and semantics can modulate these meanings. Modulation can add information about temporal and other relations between antecedent and consequent. It can also prevent the construction of possibilities to yield 10 distinct sets of possibilities to which conditionals can refer. The mental representation of a conditional normally makes explicit only the possibilities in which its antecedent is true, yielding other possibilities implicitly. Reasoners tend to focus on the explicit possibilities. The theory predicts the major phenomena of understanding and reasoning with conditionals. You reason about conditional relations because much of your knowledge is conditional. If you get caught speeding, then you pay a fine. If you have an operation, then you need time to recuperate. If you have money in the bank, then you can cash a check. Conditional reasoning is a central part of thinking, yet people do not always reason correctly. The lawyer Jan Schlictmann in a celebrated trial (see Harr, 1995, pp. 361–362) elicited the following information from an expert witness about the source of a chemical pollutant trichloroethylene (TCE):

this paper is to show that this misunderstanding of the nature of logic by these and other prominent programs of research into human reasoning, has led to an impoverishment of empirical investigation into what subjects are doing in the selection task and to a wholly unnecessary and damaging rift between logically based cognitive theories of natural language interpretation on the one hand, and psychological experimentation on reasoning on the other. We will show that when empirical exploration is based on an informed understanding of logically based cognitive theory, the evidence strongly suggests a nearly opposite evolutionary account of the relation between the emergence of human communication capacities and economic exchange, and that logical semantics already has accounts of context senstivity to o#er far in advance of mental models theory's new creations

Abstract not found

We propose a general and predictive explanation of the Wason Selection Task (where subjects are asked to select evidence for testing a conditional "rule"). Our explanation is based on a reanalysis of the task, and on Relevance Theory. We argue that subjects ' selections in all true versions of the Selection Task result from the following procedure. Subjects infer from the rule directly testable consequences. They infer them in their order of accessibility, and stop when the resulting interpretation of the rule meets their expectations of relevance. Subjects then select the cards that may test the consequences they have inferred from the rule. Order of accessibility of consequences and expectations of relevance vary with rule and context, and so, therefore, does subjects ' performance. By devising appropriate rule-context pairs, we predict that correct performance can be elicited in any conceptual domain. We corroborate this prediction with four experiments. We argue that past results properly reanalyzed confirm our account. We discuss the relevance of the Selection Task to the study of reasoning. 1.