Are you a good lie detector?

Many thanks to Dr Sharon Leal, Senior Research Fellow in Psychology at Portsmouth University, who has contributed the following ‘guest blog’.  PwC Fraud Academy members will have the opportunity to learn more from Dr Leal about detecting liars, by attending the next PwC Fraud Academy event, in London on Wednesday 8 June 2011.

Do your many years of experience in the field make you better at catching a liar than the average lay person? Sadly the chances are that they do not! Scientific research has demonstrated that most people grossly overestimate their ability to detect lies. In reality they are typically very bad at it; even professional lie catchers such as police officers and fraud investigators are barely above chance ….you’d get similar accuracy levels if you simply tossed a coin!

Why are people so bad at catching a liar? There are a number of reasons. Interview techniques are usually poor and the interviewers tend to look for completely the wrong verbal and non-verbal cues to detect deceit. Other reasons include a worrying tendency for the use of technological ‘toys’ that sound impressive but have no hard evidence to show that they work. An example of this is voice stress analysis. Indeed, the European consortium of Psychological Research for the Detection of Deception (E-PRODD www.eprodd.net), which consists of top scientific experts in the field of deception detection, warn against the use of this and other gadgets that have no scientific underpinning at all.

So can people improve their ability to detect lies? The answer is yes: by learning how to conduct better interviews and identifying the correct indicators of deceit. Both are achievable through using scientifically sound, evidence-based tools. As a result lie detection significantly improves!

Unlearning old habits and heuristics for lie detection is not easy, it takes thought and effort and of course an admission to yourself that you may have got it wrong in the past.  The benefits of more accurate lie detection far outweigh these costs though. Erroneous veracity judgements based on poor forensic techniques are not only morally wrong, they waste time, money and in some cases cost lives.