Intuitive Frequency Judgments as a Function of Prior Expectations, Observed Evidence, and Individual Processing Strategies.

Four experiments were carried out to answer a series of questions on how people formulate impressions of frequency for realistic, repetitive events. In all four studies, the basic paradigm consisted of generating or reinforcing prior beliefs regarding the causation of event streams, presenting evidence inconsistent with those prior beliefs imbedded within a primary judgment task, and measuring the perceived frequency of the observed evidence. The frequentistic events were applicants of a particular, easily recognized, and culturally salient type e.g., women minority groups. Prior expectations were created by reinforcing the actual base rates which were well known to most of the subjects with additional instruction andor consistent preconditioning data. While the findings did not answer all three questions conclusively, they suggested that prior expectations do play a significant role in subsequent estimates of observed event frequencies the effect can be ameliorated by task conditions or instructions designed to shift attention to the evidence, but much less easily than might be expected and the tendency to process or depth of processing frequentistic evidence is subject to a strong individual difference component. All these findings are consistent with an attention-control account of intuitive frequency records.