Multiple explanations for multiply quantified sentences: are multiple models necessary?

Johnson-Laird, Byrne, and Tabossi (1989) presented a theory of deductive reasoning for inference problems using multiply quantified premises (e.g., "All of the squares are connected to some of the circles"). Their theory classifies such problems into those that require subjects to construct only 1 mental model and those that require multiple models. They presented data that corroborate the theory. This article shows that Johnson-Laird et al.'s major results can be explained without invoking mental models or, in fact, deductive reasoning at all. Furthermore, it is demonstrated that, contrary to the assumption of these authors, reversing the order of the quantifiers in a multiply quantified sentence may produce a sentence that is both more difficult to comprehend and more ambiguous. Finally, some implications for theories of how people understand multiply quantified sentences are noted.