The new Yerkes study showing that chimps conform to cultural norms is all over the place and it will be interesting in the context of reading Tomasello's book in CogBlog:
Yerkes-based Experiment Confirms Cultural Transmission And Conformity In Chimpanzee Communities
Chimps Found to Conform to Cultural Norms
Chimps show social conformity
Culture and Chimpanzees
When in Rome - Chimps conform like humans.