Extra Effort During Memory Retrieval May Be Associated with Increases in Eyewitness Confidence

When testifying in court, witnesses are motivated to try as hard as possible to give an accurate account. This study tested the proposition that extra effort by eyewitnesses during a memory test can lead to higher confidence ratings without any accompanying changes in accuracy. Participant-witnesses answered multiple-choice questions about a classroom visitor who had spoken 5 days earlier. In the high-motivation condition participants could earn prizes based on their memory test performance; in the low-motivation condition there were no special incentives. Although the motivation manipulation did not affect mean witness confidence, the confidence–accuracy and effort–accuracy correlations were substantially smaller in the high-motivation condition than in the low-motivation condition. Furthermore, the confidence ratings for those participants who reported expending high levels of effort in both motivation conditions were significantly higher than the confidence ratings for the low-effort participants, despite the fact that response accuracy did not differ as a function of reported effort. These findings have important implications for understanding how pressures to perform well in the courtroom can affect eyewitness confidence.     

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.     

Public Eyewitness Confidence Ratings Can Differ from Those Held Privately

Despite much research on eyewitness confidence, we know very little about whether confidence ratings given in public might differ from those held privately. This study tested a prediction derived from self-presentation theory that eyewitnesses will give lower confidence ratings in public when there is a possibility of their account being contradicted by other witnesses as compared to when they report their confidence in private. In groups of 3 or 4 people, 96 participants watched a videotape of a simulated robbery and then answered 16 forced-choice questions about details from the videotape. In half of the experimental sessions, the participants shared their answers and confidence ratings aloud with the other participants (public condition), and in the other half, the answers and ratings were not shared (private). As predicted, confidence ratings were significantly lower in the public condition than in the private condition, but the privacy manipulation had no effect on response accuracy. These results are consistent with a self-presentation explanation, and they highlight the need to examine public confidence ratings more thoroughly.