Sense about Science ? equipping people to make sense of science and evidence
News and Comment
Sense About Lie Detectors is published today
31 July 2012
Lie detectors have been around for nearly 100 years. Despite debates over their accuracy and the ethics and legality of their use, the public and professionals remain intrigued by them. Lie detectors mainly consist of polygraphs, voice analysis or brain imaging. These technologies are different but three points are relevant to all:
- They are not accurate.
- They do not measure lies but rather something that could be a proxy for lies.
- They all rely on the deterrent effect (that is, fear of being caught lying).
Even though there is no good evidence for their accuracy, lie detectors are routinely used in the US justice system and UK statutory bodies and the Government have been interested in them. The Department for Work and Pensions tried using voice analysis lie detection to identify benefit cheats over the phone. This technology was criticised by Professor Francisco Lacerda and colleagues at Stockholm University in a review article which had to be removed after a threat of libel action. In March 2010 we arranged for Professor Lacerda to speak to MPs in the House of Commons and in November 2010 the DWP dropped the voice analysis lie detector after a review. More on this on the Liberal Conspiracy blog.
The Ministry of Justice recently recommended the use of polygraphs in managing convicted sex offenders. The report downplayed the observer bias in the research; there is a short critique of the paper by Dr Chris Tyler here.
Download the PDF of Sense About Lie Detectors here. Thank you to Dr Jamie Horder for researching and drafting the leaflet.