Racism is rational. For the same reason xenophobia is rational. Everyone practices it on a daily basis. Everyone trusts a family member who has done nothing wrong to them more than a stranger who has done nothing wrong to them. You prefer your tribe to other tribes. It's just that when it comes to race, (((some people))) have decided that it's morally wrong to be xenophobic. In reality, everyone who isn't affected by the brainwashing of the media and the school system will always have more trust for a member of their own race if all other variables are equal. That's just the natural way of things.