Abstract:

Studied whether subjects understand conditional statements ("if p then q") as indicating high conditional probability. In a series of 5 experiments (paper-and-pencil as well as Internet-based), a total of 4,376 participants estimated the probability that a given conditional is true or judged whether a conditional was true or false, after being provided with information about the frequencies of the relevant truth table cases. Judgments were influenced by the ratio of cases in which p is q and p is not q, the frequency of cases in which p is q, and the pragmatic utility associated with believing a thematic conditional statement. Results are concluded to support the conditional probability account, mental model theory, and the influence of personal utilities in the cognitive processing of conditional statements.