Helping with all your heart: the effect of cardioid dishes on tipping behavior

Some studies have shown that figurative cues, presented in the immediate environment of an individual, affect his/her later behavior. This effect was studied in a tipping behavior context. In three restaurants, each bill was placed under a dish, which had a cardioid shape, a round shape, or a square shape. Results showed that more tips were left in the bill dish with the cardioid shape. The activation spreading theory is used to explain these results.