ForensicsEyewitnesses who collaborate make fewer mistakes in police interview
Two recent studies show that witnesses make fewer errors when they are interviewed together than when they are interviewed separately. This stands in sharp contrast with current police guidelines to always interview witnesses separately.
Study indicates courts may have relied on less than reliable evidence // Source: theconversation.com
Two recently published research studies by legal psychologists Annelies Vredeveldt and Peter van Koppen at Vrije Universiteit Amsterdam show that witnesses make fewer errors when they are interviewed together than when they are interviewed separately. This stands in sharp contrast with current police guidelines to always interview witnesses separately.
VU says that in a unique collaboration between VU Amsterdam and the Toneelschuur theatre in Haarlem, in the first study the researchers asked attendees of an emotional play to testify about a rape-and-murder scene they saw a week earlier. Witnesses were interviewed either in pairs or alone. Two witnesses who were interviewed together reported the same amount of information but made substantially fewer errors than two witnesses interviewed separately. In the second study, the researchers interviewed a larger number of witnesses (80 people) and found the same result.
These findings are surprising in light of previous legal psychological research showing that witnesses can contaminate each other’s memory. The difference is that in those studies, artificial ways were used to increase errors, such as letting the witness talk to a ‘fake witness’ who purposefully introduced errors in the discussion. In contrast, the research by VU Amsterdam investigated naturalistic discussions between witnesses.
Moreover, the research showed that couples with an effective communication style remembered more together than couples who communicated less effectively. The research shows that the best way of collaborating is to repeat or rephrase your partner’s statements and then elaborate by adding extra information.
“The research findings show that collaboration between witnesses can also have benefits”, the researchers said. “Until now, most people assumed that discussion between witnesses has only disadvantages.” Vredeveldt and Van Koppen expect that this research will lead to widespread interest from both academics and police practitioners.
The studies form part of the research conducted by the Amsterdam Laboratory of Legal Psychology (ALLP).
— Read more in Annelies Vredeveldt et al., “Acknowledge, repeat, rephrase, elaborate: Witnesses can help each other remember more,” Memory 24, no. 5 (May 2016): 669-82 (DOI: 10.1080/09658211.2015.1042884); and Peter J. van Koppen et al., “When discussion between eyewitnesses helps memory,” Legal and Criminological Psychology (24 June 2016) (DOI: 10.1111/lcrp.12097)
