IMHO a more accurate description is "It's beneficial for me if my tribe acts to help its members at the expense of members of other tribes, instead of treating

IMHO a more accurate description is "It's beneficial for me if my tribe acts to help its members at the expense of members of other tribes, instead of treating everyone equally" (which may or may not be true depending on the situation, and how influential your tribe is), with no value judgement necessary.