When someone smiles, the effects are often positive: a glum mood lifts; an apology is accepted; a deal is struck; a flirtation begins. But change the circumstances or the cast of a smile and the terms shift: a rival grins to get under your skin; a bully's smirk unsettles his mark. "A masterly example of social sciences at its best" (The Wall Street Journal), Why Smile? investigates the familiar grin and finds that it is not quite as simple as it first appears. Marianne LaFrance shows how the smile says much more than we realise - or care to admit. This groundbreaking and insightful work explores such questions as whether popular or unpopular children show more fake smiles or whether it is good or bad when a bereaved person smiles. To read it is to learn just how much the smile influences our lives and our relationships.