The primacy of generalities in hypothetical reasoning

Abstract

Subjects were given a noncontradictory set of propositions followed by a sentence which they had to accept as true. This sentence introduced an inconsistency which the Ss were required to resolve by assigning truth values to the statements. In previous work, the authors found that when forced to choose between the truth of a generality ( All A's are B's) and that of a particular fact ( This Y is a Z), subjects consistently rejected the fact in favor of the generality. Affirmative generalities were accepted more often than negative ones, and those expressing class-inclusion were accepted more often than those expressing property-assignment. The present experiments show that preference for generalities is independent of (a) the superficial form of the generality (i.e., the surface presence of a quantifier), (b) the polarity of the contrasted fact (affirmative or negative), and (c) the terms used to express the relations ( is a and has a). The preference for reasoning with generalities is enhanced when they assert generally known facts which are not delimited in space or time. A theoretical treatment of the results employing the calculus of modal logic was explored.