Public eyewitness confidence can be influenced by the presence of other witnesses.

Four experiments were conducted to examine whether witnesses' public confidence ratings differ from their private ratings when there are social pressures to use confidence as an impression-management tool. In all four experiments, participants answered questions about a source event (a series of faces in the first three experiments and a simulated crime scene in the fourth). Half of the responses and confidence ratings were given privately and anonymously, and half were given publicly in front of one or more mock jurors. Two central findings emerged from the results. First, public confidence differed from private confidence only when there was more than one witness; when there were no other witnesses, public and private confidence were the same. Second, the direction of the change in public confidence in the multiple-witness settings was influenced by whether or not there was a possibility of being contradicted by the other witnesses. When there was no chance that the participants' responses could be contradicted, they raised their confidence ratings in public; when there was a chance that the other witnesses might contradict them, the participants lowered their public confidence ratings. The results are discussed in terms of self-presentation theory and implications for the legal system.