Interpretational errors in syllogistic reasoning

Abstract

The purpose of this research was to investigate whether subjects interpret quantifiers in the way predicted by theories of syllogistic reasoning. In Experiment 1, subjects indicated which Euler circle diagrams were appropriate with different quantifiers, and the results provided support both for conversion theory and for predictions derived from Grice's (1975. Syntax and Semantics, Vol. 3, Speech Acts. New York: Academic Press) theory of conversational implicatures. In Experiment 2, subjects carried out both an Euler circle task and an immediate inference task, followed by a test of syllogistic reasoning performance. It was found, surprisingly, that interpretational errors as determined using the Euler circle task showed no correlation with the same errors measured using an immediate inference task. It was concluded that performance on both these tasks can be affected by response biases, but that they are valid in certain contexts. Both conversion theory and Gricean theory were supported by the results of the syllogistic reasoning task, since subjects assessed as making these interpretational errors produced the predicted responses on this task.