'Atmosphere', matching, and logic in syllogistic reasoning

The frequency of error in syllogism solving suggests that not all subjects are using logic. The atmosphere and matching hypotheses suggest what they might be doing instead but predict some of the same (correct and incorrect) responses. Reexamination of the data supporting the atmosphere hypothesis (Sells, 1936) shows that the procedure employed was unsatisfactory and that the results obtained support the matching hypothesis as well as they support the atmosphere hypothesis. It is argued on theoretical grounds that the matching hypothesis should be preferred. An experiment is reported in which subjects (N = 71) were required to draw conclusions from syllogistic premises and to construct premises from which given conclusions followed. It is shown that subjects may be divided into three groups: (n = 16) consisting of subjects who used logic and made few errors; (n = 25) of subjects whose correct and incorrect responses were in accordance with the matching hypothesis; and (n = 30) of subjects who were not matching but trying to do logic and not doing it well.