When you take the test, you're shown a short video clip of someone smiling and asked whether you think it's real or fake. I didn't do so well - 12/20, but I do have some advice: just go with your instincts, they aren't trying to fake you out. I second-guessed myself on a lot, and the times when I second-guessed myself were where I made the mistakes. I think there were only 2 or 3 where I really was totally off, the rest of the ones I got wrong were just a case of thinking they must be trying to trick me and switching my answer. I dunno.
http://www.bbc.co.uk/science/humanbody/mind/surveys/smiles/index.shtml
