Everyone lies every day. One study concluded that strangers and loose acquaintances lie to each other at the rate of about three times in a ten-minute conversation. Several studies have concluded that most people are on the receiving end of two hundred lies in a waking day. That’s twelve lies an hour! Lies are to human interaction as bacteria are to food: they’re all over it and you have no idea. The good news is that most of the time it doesn’t matter. But what if something big is at stake, like your money or your heart? Assuming their nose doesn’t grow an inch or their pants don’t catch on fire, how can you know you’ve got a liar on your hands?