Psychologists at the University of Herefordshire in England have conducted studies on hundreds of people to determine what makes some people lucky and others not.  What is luck?  Where does it come from? And how do we get more of it?  Put aside your lucky charms, amulets, and talismans.  No need to awaken the tree gods by knocking on wood. The psychologists unearthed four principles that really work and which are accessible to all of us.