The art of haggling is a very particular skill. Mind games play a huge role and it can be next to impossible to figure out whether or not you are really getting the best deal. However, it's not just the mind that comes into play when trying to negotiate a bargain - analysing body language is just as important as weighing out the pros and cons of a deal. According to Wray Herbert, author of On Second Thought: Outsmarting Your Mind’s Hard-Wired Habits, there are four key signs that indicate the person you are dealing with is not trustworthy. Referring to a body language study which saw participants attempt to detect fraudulent behaviour, he notes: "They isolated the specific cluster of cues that were actually present when volunteers successfully detected others’ self-serving intentions. "Again and again, it was a cluster of four cues: hand touching, face touching, crossing arms, and leaning away.  "None of these cues foretold deceit by itself, but together they transformed into a highly accurate signal. And the more often the participants used this particular cluster of gestures, the less trustworthy they were in the subsequent financial exchange." Hmm. Good to know.