The present study was designed to test whether or not the use of representativeness and causality heuristics in decision-making results from insufficient or nonvigilant information processing rather than from an inherent deficiency in human information-processing ability. It was hypothesized that subjects who were distracted while making predictions (field-dependent subjects who were continuously aware of other subjects' performance in the experimental session) would fail to use the base rate to a greater extent than would nondistracted subjects (field-dependent subjects who were not aware of the other subjects' performance, and field-independent subjects). As predicted, when other subjects' performance was public, field-independent subjects conformed more to the base rate than did field-dependent subjects. In the private condition, however, the opposite pattern emerged. The results were discussed in terms of the drive theory of social facilitation and non-vigilant information processing.