"Good, you identified the suspect": Feedback to eyewitnesses distorts their reports of the witnessing experience.

TLDR

Participants watched a security video, attempted to identify the gunman from a photo spread, and then received either confirming, disconfirming, or no feedback about their identification. Because the actual gunman was absent from the photo spread, all witnesses made false identifications, and the feedback manipulation markedly altered their retrospective reports of certainty, view quality, memory clarity, identification speed, and other measures, even among those who denied being influenced.

Abstract

People viewed a security video and tried to identify the gunman from a photospread. The actual gunman was not in the photospread and all eyewitnesses made false identifications (n = 352). Following the identification, witnesses were given confirming feedback (Good, you identified the actual suspect), disconfirming feedback (Actually, the suspect is number ―), or no feedback. The manipulations produced strong effects on the witnesses' retrospective reports of (a) their certainty, (b) the quality of view they had, (c) the clarity of their memory, (d) the speed with which they identified the person, and (e) several other measures. Eyewitnesses who were asked about their certainty prior to the feedback manipulation (Experiment 2) were less influenced, but large effects still emerged on some measures. The magnitude of the effect was as strong for those who denied that the feedback influenced them as it was for those who admitted to the influence.