Estimating the effects of misleading information on witness accuracy: can experts tell jurors something they don't already know?

Abstract

This study investigated potential differences between expert and lay knowledge of factors influencing witness suggestibility. Expert psychologists (N ¼ 58), jurors (N ¼ 157), and jury-eligible undergraduates (N ¼ 220) estimated the effects of misleading information on witness accuracy for three age groups in various conditions. Respondents possessed similar knowledge of age-related trends in suggestibility, the positive effects of a pre-misinformation warning, and the negative influence of longer delays between the event/misinformation and event/final memory test. Compared to experts, laypeople underestimated the size of suggestibility differences between age groups and lacked knowledge about how event detail centrality, witness participation, and source prestige can increase witness suggestibility. Laypeople rated themselves as being largely unfamiliar with witness suggestibility research and thought that expert testimony would be beneficial. These data shed light on the potential helpfulness of expert testimony in cases involving witness suggestibility.

Jurors' perceptions of juvenile defendants: the influence of intellectual disability, abuse history, and confession evidence

“…These findings comport with the body of work finding that prospective jurors understand that child witnesses are more suggestible than adults in the context of forensic interviews (e.g. McAuliff & Kovera, 2007;Quas, Thompson, & Clarke-Stewart, 2005).…”

How Common is “Common Knowledge” about Child Witnesses among Legal Professionals? Comparing Interviewers, Public Defenders, and Forensic Psychologists with Laypeople

“…Previous research has consistently shown few differences between the responses of undergraduate college students and those of jury-eligible citizens (see Bornstein, 1999). Of importance, for the purposes of this study, Quas et al (2005) and McAuliff and Kovera (2007) found that beliefs or knowledge about child witnesses were rarely different for their college versus jury samples.…”

“…A second shortcoming of most studies is the use of the all-inclusive term "children" (for exceptions, see McAuliff & Kovera, 2007;Quas et al, 2005). Developmental changes in memory and suggestibility are pervasive and dramatic (Ceci & Bruck, 1993, 1995, with preschoolers being most vulnerable to memory loss, distortion and suggestibility (although see Brainerd & Reyna, 2012).…”

“…However, laypeople have limited knowledge about the influence of various suggestive techniques or other factors that influence memory accuracy. For example, they did not understand how participation in an event, the delay between the interview and event, or warnings about suggestive information influence misinformation effects (McAuliff & Kovera, 2007). The study by Quas et al (2005) presents the most detailed account of jury-eligible adults' knowledge of the scientific literature on children's suggestibility.…”

“…First, with a few exceptions (e.g., McAuliff & Kovera, 2007;Quas, Thompson, & Clarke-Stewart, 2005), these studies included only very general questions (e.g., "Children are more suggestible than adults," "Children are less accurate than adults," "Children can be good witnesses"). However, scientific research and expert testimony on children's memory and suggestibility involve far more than the average accuracy or suggestibility of children relative to adults.…”