The effects of alcohol and co-witness information on memory reports: a field study

Abstract

Rationale Witnesses who discuss a crime together may report details that they did not see themselves but heard about from their co-witness. Co-witness information may have beneficial and harmful effects on memory accuracy depending on whether the information was correct or incorrect. Objectives Given the prevalence of intoxicated witnesses, it is imperative to understand how alcohol influences this effect. Methods The present study asked pubgoers (n = 67) at varying levels of intoxication to recall a mock crime video after having also watched a video witness statement containing both correct and false information. Results Increased intoxication was associated with decreased confidence, completeness and accuracy, but no increased tendency to report false information. Exposure to incorrect post-event information (PEI) can lead to the incorporation of incorrect information, whereas exposure to correct PEI increased accuracy, regardless of individuals’ alcohol intoxication status. Conclusions Thus, whilst discussion and intoxication can negatively impact eyewitness memory, discussion may also have benefits for both sober and intoxicated witnesses.

The importance of the smallest effect size of interest in expert witness testimony on alcohol and memory

“… Crossland et al (2020) , for example, showed that although intoxicated participants did not additionally benefit from receiving a well-conducted interview, all participants (intoxicated or not) did have more complete statements when a well conducted interview was applied. Apart from Jores et al’s meta-analysis, future meta-analyses might concentrate on other important practical aspects on how alcohol affects memory such as whether it might affect the reporting of suggested information or whether a Cognitive Interview might counteract the debilitating memory effects of alcohol (see also Bartlett et al, 2022 ).…”