ABSTRACT
Belief revision occurs when one moves from one belief state to another after encountering some data that are inconsistent with one’s initial belief set. Experiments in belief revision have demonstrated that the initial logical structure of an argument affects how reasoners revise their beliefs. When arguments for changing beliefs are made in a logical form, the typical finding is that the major premise is revised more frequently than the minor premise. This is evident when the modus ponens (MP) inference is contradicted (if p then q; p; therefore, q), while there is no clear preference when the modus tollens (MT) inference is contradicted (if p then q; not q; therefore, not p) (Dieussaert, Schaeken, De Neys, & d’Ydewalle, 2000; Elio & Pelletier, 1997; Politzer & Carles, 2001). Others have reported a different finding: reasoners revise belief in the major and minor premises equally often in MP problems, but prefer to disbelieve the minor premise in MT problems (Revlin & Calvillo, 2002; Revlin, Cate, & Rouss, 2001). In three experiments, we explore possible explanations for these two different patterns of results.
