Deception Blog

… according to a press release from the Economic and Social Research Council (7 June):

Shifting uncomfortably in your seat? Stumbling over your words? Can’t hold your questioner’s gaze? Police interviewing strategies place great emphasis on such visual and speech-related cues, although new research funded by the Economic and Social Research Council and undertaken by academics at the University of Portsmouth casts doubt on their effectiveness. However, the discovery that placing additional mental stress on interviewees could help police identify deception has attracted interest from investigators in the UK and abroad.

[...] A series of experiments involving over 250 student ‘interviewees’ and 290 police officers, the study saw interviewees either lie or tell the truth about staged events. Police officers were then asked to tell the liars from the truth tellers using the recommended strategies. Those paying attention to visual cues proved significantly worse at distinguishing liars from those telling the truth than those looking for speech-related cues.

[...] However, the picture changed when researchers raised the ‘cognitive load’ on interviewees by asking them to tell their stories in reverse order. Professor Aldert Vrij explained: “Lying takes a lot of mental effort in some situations, and we wanted to test the idea that introducing an extra demand would induce additional cues in liars. Analysis showed significantly more non-verbal cues occurring in the stories told in this way and, tellingly, police officers shown the interviews were better able to discriminate between truthful and false accounts.”

Asking an interviewee to tell their story in reverse order is not a new interview technique – it’s one of the techniques used in the Cognitive Interview, more usually deployed to get maximum detail in statements from victims and witnesses.

There are also detailed articles in the UK Times and Daily Telegraph newspapers based on (and building on) this press release.

More details, and links to downloadable reports, are available on the ESRC website via this link.

References:

• How to tell a liar: tell it backwards (Daily Telegraph, 7 June)
• Can the suspect tell his story backwards? If he can’t, he’s lying (The Times, 7 June)
• Vrij, Aldert (2007). Interviewing to Detect Deception: Full Research Report. ESRC End of Award Report, RES-000-23-0292. Swindon: ESRC

Photo credit: Bingo_little, Creative Commons License