Monetary significance of the affiliative smile: A case for reciprocal altruism
Whether smiling could accrue monetary returns was tested. Two degrees of smiling to single men and women (N = 96) by a waitress in a cocktail lounge was evaluated in terms of number of drinks ordered, size of tip, and whether the customers smiled upon departure. A broad smile reaped more money than a minimal smile and more from men than from women patrons. The results are discussed in terms of reciprocal altruism.