This article is based on the proposition that people attribute a disposition to an actor by evaluating its consistency with other information about the actor or the situation. This strategy is assumed to be accompanied by a cognitive set or bias to view ambiguous information as consistent with the hypothesized disposition. Respondents were told that a student had chosen or had been assigned to write a proabortion or antiabortion paper, and they were or were not given an ambiguous description of the author's personality. In support of predictions, under choice conditions attitudes were always attributed in accordance with the paper's position, but under assignment conditions such attributions occurred only when respondents received the ambiguous personality description. A central focus of attribution theory is the extent to which an actor's behavior provides information about his or her stable underlying dispositions (cf. Ajzen, 1971; Jones & Davis, 1965; Steiner, 1970). Most analyses of the attribution process (e.g., Heider, 1958; Jones & Davis, 1965; Kelley, 1967) have likened observers to naive scientists who, except for a few motivational biases, make systematic use of the information available to them. It has recently been suggested, however, that instead of using sophisticated information-processing strategies, people rely on rather simple intuitive heuristics (Tversky and Kahneman, 1974) or cognitive scripts (Abelson, 1976) in making their judgments (see Slovic, Fischhoff, & Lichtenstein, 1977, for a review). Although these intuitive strategies often produce reasonable judgments, they are said to be capable of leading to systematic biases and errors (Ajzen, 1977; Kahneman & Tversky, 1973; Nisbett & Borgida, 1975). This article deals with what Ross (1977) has termed the fundamental attribution error, the assumed tendency for observers to overestimate the importance of dispositional fac