I read &quot;What every body is saying&quot; by Joe Navarro, an ex. FBI agent a few years back, and one of things it spent a lot of time on was tearing apart the notion that we can recognise liars by body language without knowing them well first. People do have &quot;tells&quot;, but as the article says, they vary wildly from person to person.<p>They&#x27;re still interesting to look out for, though, as they&#x27;re helpful hints to let you direct your conversation to probe at areas that makes someone nervous and&#x2F;or to figure out what someones different tells means.