As a SoCal transplant to the bay area, my biggest observation is that it's basically mandatory to "have a cause" in the bay area. It doesn't really matter what it is. It could be cycling over driving. It could be how you eat. It could be political activism. But it has to be something, or people look at you funny.

Aside from the Venice Beach / Santa Monica scene (which is absolutely superficial), I find SoCal to be much more laid back. Live and let live, if you will.