An inferential approach to the knew-it-all-along phenomenon.

Two studies tested the hypothesis that the knew-it-all-along effect may be the result of an inferential process. Specifically, that individuals use their feelings and experiences (e.g., "This question seems so familiar to me, surely I would have known the answer!") to infer their judgement. Drawing on subjective feelings such as certainty or perceptual fluency, individuals can use a provided actual value as an informational cue and draw inferences from it. Thus, the occurrence of the knew-it-all-along effect is expected to depend on the experienced feeling of confidence with a question. This feeling may indicate to an individual that he or she did know the answer; a total lack of such a feeling may suggest that he or she never would have known the answer. In the reported studies we both measured feelings of confidence (Study 1) and induced them by manipulating perceptual fluency (Study 2) to show that the knew-it-all-along effect proves to be a phenomenon of inferences based on these experienced feelings. Participants experiencing high confidence or high perceptual fluency more strongly assimilated their judgements to the provided values, than did participants experiencing low confidence or low perceptual fluency.