Witnesses' susceptibility to misleading post-event information delivered in a social media-style video

In many criminal cases, outcomes rely on eyewitness evidence. Exposure to misleading information after an event reduces the accuracy of witnesses' memories. In some circumstances, warnings about misinformation can protect witnesses. As social media is a growing source of misleading information, this study examined the effect of misleading post-event information delivered via a social media-style video, as well as the utility of a minimal versus detailed warning. Participants (N = 145) watched a video showing an electrician stealing items from a client's home. Next, they received one of three pre-warnings regarding forthcoming misleading information: a minimal warning indicating that caution should be taken, a detailed warning specifying the presence of misleading information, or no warning. Participants received the misleading information via a social media video or a standard text-based narrative. Finally, they completed a recognition test. Although delivery method did not affect errors for misleading items, detailed warnings were only effective against text-based misleading information. Participants were more confident about their correct than incorrect responses for misleading items; confidence was not affected by delivery method or warning. This experiment is the first to demonstrate people's susceptibility to misleading post-event information delivered in a social media-style video using an eyewitness paradigm.