Another bitter stereotype contributing to the US cultural divide. I live in an economically diverse but mostly well-off white collar suburb (not in CA), and we have a strong sense of community. We walk to each other's houses on a whim, we help each other get things done, we shovel the snow for the older folks, we watch out for each other and text each other, we organize community get-togethers. I realize this is an anecdote - I am not saying the correlation you're describing isn't statistically real, just that it's pointlessly negative.