The Utilitum Game and the Mazzi Gankar

The Mazzi Gankar are pretty individualistic and independent. They're not worried about things like conformity compared to other populations I've worked with. In a behavioral game called the ultimatum game, they would make very low offers that were almost always accepted. This got me wondering what's explaining this difference and this inclinations towards fairness. These are just tapping norms about how to deal with people you don't have relationships with in monetary interactions.