I like your points about what makes an organization have influence over its members, and I think you are spot-on about the different ways that are effective in creating group cohesion. However, I don't think that Catholic charity is so much mandated by the church as a rule or even an expected behavior as it is a product of the culture. When Catholics give to charity, it feels like an individual and optional choice. Whereas going to church and not using birth control may feel more like following the rules. I think there is a difference between behaviors that are done to identify with a group verses behaviors that done because you identify with that group..

The analogy would be rationalists doing something rational not because they're told to, but because they believe in rationality. That's why they're in the group in the first place.