A Heart-Shaped Bowl Makes You More Altruistic

46.3% of restaurant customers left tips when they were given heart-shaped dishes for their money, compared with just 31.2% and 26.2% when the tip dishes were round or square, respectively, says Nicolas Guéguen of the Université de Bretagne Sud in France (the experiment was conducted in France, where tipping is not expected because a service charge is included in the bill). The findings suggest that a simple physical cue such as a heart-shaped bowl can induce thoughts of love, which activate altruism and helping behavior.