The meaning(s) of conditionals: conditional probabilities, mental models, and personal utilities.
Five experiments were conducted to test the hypothesis that people understand conditional statements ("if p then q") as indicating a high conditional probability P(q/p). Participants estimated the probability that a given conditional is true (Experiments 1A, 1B, and 3) or judged whether a conditional was true or false (Experiments 2 and 4) given information about the frequencies of the relevant truth table cases. Judgments were strongly influenced by the ratio of pq to p not q cases, supporting the conditional probability account In Experiments 1A, 1B, and 3, judgments were also affected by the frequency of pq cases, consistent with a version of mental model theory. Experiments 3 and 4 extended the results to thematic conditionals and showed that the pragmatic utility associated with believing a statement also affected the degree of belief in conditionals but not in logically equivalent quantified statements.
Oberauer
Klaus
K
Allgemeine Psychologie I, University of Potsdam, Germany. ko@rz.uni-potsdam.de
Wilhelm
Oliver
O
D000293:Adolescent; D000328:Adult; D003071:Cognition; D005260:Female; D006801:Humans; D008037:Linguistics; D008128:Logic; D008297:Male; D012660:Semantics