Three experiments investigated a phenomenon of memory distortion. Social influence, in the form of bogus feedback information about the accuracy of an interpersonal judgment, dramatically distorted people's recollections. Participants in all three experiments watched a short video of a couple interacting. After the video was over, participants either judged which person had an affair or which person committed suicide (Experiment 1 only). After making their decision, participants were randomly assigned to hear bogus confirming ("Yes, that is the person who had the affair [committed suicide]") or disconfirming ("Actually, it was the other person who had the affair [committed suicide]") feedback. Participants in Experiment 1 (N = 98) who heard confirming feedback reported recalling more certainty in their decision, making their decision more easily, having a better basis for their decision, making their decision more quickly, being better at making judgments about others in general, and other distortions in recollection. This pattern of results was labeled the "post-decision feedback effect." Experiment 2 (N = 128) eliminated the possibility that the post-decision feedback effect is caused by participants' self-presentation concerns. Experiment 3 (N = 429) tested competing hypotheses for the post-decision feedback effect: anchoring and adjustment versus biased search of memory. Three variables were manipulated: post-decision feedback (Confirming vs. Disconfirming), completing dependent measures questionnaire under time pressure (Yes vs. No), and completing the dependent measures under cognitive load (Yes vs. No). The magnitude of the feedback effect was not changed by the resource constraint manipulations suggesting that the feedback effect is a highly automatic process.