Why groups tip less
In 1975, researchers Freeman, Walker, Borden, and Latané studied
tipping at a Columbus, Ohio restaurant. Their paper, aptly titled
“Cheaper by the Dozen,” documented something servers already knew:
42%Groups of 6 tip 42% less per person than solo diners.
19% tip for solo → 11% for groups of 6.
The phenomenon is called diffusion of responsibility.
In a group, everyone assumes someone else is handling the tip. “I’ll
just match what everyone else does.” But everyone thinks this
simultaneously—so everyone tips low.
19%average tip from solo diners
16%average tip from pairs
11%average tip from groups of 6
This is why many restaurants add automatic gratuity for large parties.
It’s not greed—it’s behavioral economics. Without it, servers who
work the hardest tables would earn the least. The problem is worst at
bachelor and
bachelorette dinners, where 12-person tables, varying drink
orders, and celebration dynamics amplify every group-size effect.
The 800,000-transaction study. In 2022, researchers
Haugom and Thrane analyzed over 800,000 restaurant transactions in
Norway. They confirmed the pattern holds across cultures: group size
and dining duration have hill-shaped nonlinear effects on
tipping behavior.
Sources: Freeman et al., Personality and Social Psychology Bulletin, 1975; Haugom & Thrane, J. Economic Behavior & Organization, 2022