@Lizzz @cassandra17lina * The whole host of reasons is studies show most will self-report the amount they tip is driven by quality of service they get. Yet those studies show in controlled tests, service quality is the least driver of how people actually tip. Real drivers are race and sex (of the server and the customer), attractiveness, how much they touch you, whether they squat by the table, etc.
Quality of service was purposely manipulated in the tests and it didn't change the amounts,