"There are some pointers to the evolutionary origins of deceit. A few years ago, animal researcher Maxine Morris observed some rather curious behaviour among a group of Asian elephants at Washington Park Zoo. At feeding time, each elephant was given a big bundle of hay. Morris noticed that a couple of the elephants tended to eat their own hay quickly, sidle up to their slower-eating companions, and then start swinging their trunks from side to side in a seemingly aimless way. Morris's repeated observations suggested that this apparently innocent behaviour masked a duplicitous intent. Once the trunk-swinging elephants were sufficiently close to another elephant, they would grab some of the uneaten hay, and quickly gobble it up
Liars often try psychologically to distance themselves from their falsehoods, and so tend to include fewer references to themselves in their stories.
According to Freud, jokes act as a kind of psychological release valve that helps prevent the pressure of repression from becoming too great."
