Repeated information in the courtroom

It is widely understood among scientists and criminal and civil lawyers that eyewitnesses are often inaccurate, and that inaccurate information can contaminate memories of other eyewitnesses.1 It is less widely known—although no less true—that when misleading claims are repeated, they are more likely to damage other people’s memories than when those claims are made only once.2 But until recently, neither lawyers nor scientists knew the answer to these questions: Does one person repeating an inaccurate claim do more damage to the memories of other eyewitnesses than that same person making the claim only once? And when that inaccurate claim is repeated, does it matter how many people make it? In this paper, we address those questions.