Repeated postevent questioning can lead to elevated levels of eyewitness confidence

Two experiments tested the proposition that postevent questioning can lead to later increases in witness confidence without corresponding changes in witness accuracy. After a staged interruption in a college classroom, participants were questioned about the event 5 times over 5 weeks in Experiment 1 (n=57) and 3 times over 5 days in Experiment 2 (n=79). During the final questioning session, the participant-witnesses consistently reported higher levels of confidence for those items that had been subject to repeated postevent questioning than for those items that were asked for the first time, yet there was no difference in the accuracy of the responses to the two sets of items. Additionally, in all conditions the participant-witnesses were generally overconfident in their responses. These results suggest that repeated postevent questioning can cause eyewitnesses' subsequent confidence estimates to be artificially inflated.