With the movement to end restaurant tipping steadily gaining momentum, or at least greater acceptance, the parallel debate over how discriminatory the practice actually is has become more prominent. The answer to that question, according to science and compiled very scarily by The New Republic, is "probably several thousand ways."
The New Republic has a few concrete examples, based on real research published between 1980 and 2012, of what customers looking to leave an arbitrary percentage of the dinner check are possibly responding to, you know, on a deeper level. Sure, service with a smile is always a plus, but a number of studies allegedly indicate, for what it's worth, "attractive" women are tipped better. Not only that, but in what sounds like a set of rules formatted by sexist eleventh-grade dudes, more tips are reportedly allocated to the aforementioned servers who also:
• Are blonde.
• Wear red. (This snags "significantly larger tips" than other colors.)
• Briefly touch the customer's hand twice, and twice-only, for half a second. (Tips climb from 12 to 17 percent.)
• Draw smiley faces on the check. (Men, take heed: It's "cute" coming from a woman, but "effeminate" from a man.)
• Put a flower, a barrette, an ornament, something really doesn't matter what in their hair.
• Crouches beside the table.
So, basically, everyone's worst nightmares about the service industry come true.