In the first few minutes of the first episode of Lie To Me the prisoner showed what we call an emblematic slip, the equivalent in gesture of a slip of the tongue. I use the term 'emblem' for any gesture that has a precise meaning known to all members of a cultural group - such as the A-OK emblem in the U.S. (Watch out; emblems are specific to each culture. Someone will slug you if make the A-OK emblem in Sicily where it refers to what is considered a perverse sexual practice!)

Typically emblems are made in what I call the 'presentation position', very noticeable because they are performed right in front of the person making it and very pronounced, with a beat. Emblematic slips are made outside of the presentation position, and usually they are only a fragment of the full emblem, performed without a beat. That is what the prisoner did, he showed just a fragment of the shrug that means 'I don't know' or 'I can't do it'. The person showing the emblematic slip knows what he or she is thinking but doesn't know it has leaked out. More about emblems in the third issue of my newsletter Reading Between The Lies.

Read Paul Ekman's comments on other events in each week's show in his weekly column

"The Truth About Lie to Me" by clicking here.