The effect ofsome andall on reaction time for semantic decisions.

Two experiments tested a model proposed by Meyer (1970) to account for the times required to verify semantic-memory statements quantified byall orsome. Each S was presented with bothall andsome statements in a mixed list, and the discriminability of false statements of the two quantifier types was controlled. In Experiment I positive subset statements ("horses are animals") were verified more quickly when quantified byall rather thansome; the reverse ordering occurred for negative subset statements ("horses are not animals"). Sentences with pseudowords in subject or predicate position took longer to reject than false real-word sentences. These findings contradict :Meyer's theoretical predictions and suggest that his earlier results were artifactual. Experiment II replicated the faster verification of positive subset statements quantified byall. This result was further shown to be predictable from the frequency with which Ss gave the predicate as a completion ofAll/Some S are _. The production frequency of predicates which form subset statements was lower when the quantifier wassome rather thanall. However, holding predicate production frequency constant, sentences with different quantifiers were verified equally quickly.