Using the latest scientific research he believes anyone can spot a fake smile, tell if someone is lying and - perhaps most importantly of all - tell if a member of the opposite sex is interested in you. Fertility expert Lord Winston, who researched the subject for his BBC1 programme The Human Mind, to be broadcast on 15 October, said: "Going to a party is one of the most complex things our brain undertakes. It performs a phenomenal amount of extremely complex tasks, all at an amazing speed."