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Cognitive approach to lie detection rendered useless by made-up alibi

08 February 2018

The desire to catch people in a lie has led to the development of techniques that are meant to detect the physical markers of dishonesty – from the polygraph to brain scans. However, these methods are often found wanting.

The insights of cognitive psychologists have arguably fared better, based on the idea that lying is more mentally demanding than telling the truth – real knowledge is automatically called to mind when we are questioned, and this needs to be inhibited  before we answer, leading to slower responses.

Unfortunately new research in the Journal of Experimental Psychology: Applied seems to pour cold water on the idea of using these subtle reaction-time differences to develop objective (and cheap) measures to get at the truth. The findings suggest that all it takes to render this cognitive approach ineffective is a prepared false alibi.

The University of Würzburg team led by Anna Foerster set up a quasi-realistic situation, sending each of their 36 participants into a room – containing various items like a computer, pen and paper and USB stick – to read instructions in a sealed envelope that sent them on a mission. 

Read more on our Research Digest blog.


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