Originally Posted by Sly

Safety is our root basic need. By sticking with our "tribes" we find safety, which solves one of our basic needs and thus allows us to focus our energy on other needs higher up the chain. Essentially a least common denominator that we want to solve as easily as possible, which again we do this by sticking with people that are "like" us. Be that religion, skin color, gender, values, location, experiences, beliefs, interests, the list goes on.

We are wired to fear "differences" because for hundreds of thousands of years, some body or some thing that was "different" meant death. Over the last several centuries we have socialized ourselves slowly out of that thinking but it's still built into us. We will always fear what we do not know and we will always gravitate towards what we do know.