It's an evolutionary benefit, really. The closer they are genetically to you, the closer it is between you passing on your genes and them passing on their genes. Doesn't make too much of a difference between an individual having kids and a family having kids. It's evolutionarily useful to care for the family's kids because they aren't that far off.

Plus, if you are willing to help a genetically similar person, since they are genetically similar it is fairly likely they may be willing to help back if they can.

I don't think the hierarchy of yourself, family, extended family/tribe, race, will ever completely go away, nor do I think it really should. If it did then groups would be acting in self destructive ways which I think is happening a bit today with white people and some "anti-racist" measures such as affirmative action.

I figure that ideally it just won't be especially important for any group and we'll be able to coexist fine. The problem exists when one race holds race to be more important when other races do not. It's a terrible idea to be impartial others aren't.