The major distinction is that, in theory, some of those tribes are by choice, and some are unable to be changed. In the US, discrimination against unchangeable

The major distinction is that, in theory, some of those tribes are by choice, and some are unable to be changed. In the US, discrimination against unchangeable characteristics is illegal in many cases (skin color, gender, etc...) I can choose to join the vegetarian tribe, and I can choose to leave it. I cannot choose the color of my skin or my race.