A study is reported testing two hypotheses about a close parallel relation between indicative conditionals, if A then B , and conditional bets, I bet you that if A then B . The first is that both the indicative conditional and the conditional bet are related to the conditional probability, P(B|A). The second is that de Finetti's three-valued truth table has psychological reality for both types of conditional— true , false , or void for indicative conditionals and win , lose (...) , or void for conditional bets. The participants were presented with an array of chips in two different colours and two different shapes, and an indicative conditional or a conditional bet about a random chip. They had to make judgements in two conditions: either about the chances of making the indicative conditional true or false or about the chances of winning or losing the conditional bet. The observed distributions of responses in the two conditions were generally related to the conditional probability, supporting the first hypothesis. In addition, a majority of participants in further conditions chose the third option, “void”, when the antecedent of the conditional was false, supporting the second hypothesis. (shrink)

Two types of truth table task are used to examine people's mental representation of conditionals. In two within-participants experiments, participants either receive the same task-type twice (Experiment 1) or are presented successively with both a possibilities task and a truth task (Experiment 2). Experiment 3 examines how people interpret the three-option possibilities task and whether they have a clear understanding of it. The present study aims to examine, for both task-types, how participants' cognitive ability relates to the classification of the (...) truth table cases as irrelevant, and their consistency in doing so. Looking at the answer patterns, participants' cognitive ability influences their classification of the truth table cases: A positive correlation exists between cognitive ability and the number of false-antecedent cases classified as ?irrelevant?, both in the possibilities task and the truth task. This favours a suppositional representation of conditionals. (shrink)

Two types of truth table tasks are used investigating mental representations of conditionals: a possibilities-based and a truth-based one. In possibilities tasks, participants indicate whether a situation is possible or impossible according to the conditional rule. In truth tasks participants evaluate whether a situation makes the rule true or false, or is irrelevant with respect to the truth of the rule. Comparing the two-option version of the possibilities task with the truth task in Experiment 1, the possibilities task yields logical (...) answer patterns whereas the truth task yields defective patterns. Adding the irrelevant option to the possibilities task in Experiment 2 leads to a considerable amount of defective patterns in the possibilities task, but still to more logical patterns in the possibilities task than in the truth task. Experiment 3 shows that directionality matters since rule-to-situation tasks yield more logical answer patterns than do situation-to-rule tasks. We conclude that both task types are not comparable as such since wording, number of options and directionality influence the results. (shrink)