There is a general idea that waiters and waitresses are more likely to receive larger gratuities from large groups of people. A recent research study suggests this is not true. The researchers examined the relationship between the size of tips in restaurants and the number of meals charged on the bill. They found that, while most tips were around 15 percent, the minimum percentage considered appropriate, people dining alone tipped consistently more (19 percent) and those dining in groups of four or more tipped considerably less (13 percent) than this 15 percent standard. These results strongly suggest that people dining in a group are less likely to feel personally responsible for leaving an adequate or generous tip.