Interesting idea. How much shared experience is there though - for example between poor and affluent people of the same race? What about immigrant groups who look similar but have very different culture and experiences? I cannot imagine an affluent black African immigrant will have much in common with a poor black American. I know that (in the UK, but it would be just as true in the US) that I do not have much shared experience with other people who look like me (South Asian to Western eyes) but come from different cultures types of area (urban vs rural is a big difference) and family backgrounds.