You seem uncharacteristically un-skeptical of convergence within that very large group, and between that group and yourself.
You are correct that there is a possibility of divergence even there. But, I figure that there's simply no way to narrow CEV to literally just me, which, all other things being equal, is by definition the best outcome for me. So I will either stand or fall alongside some group that is loosely "roughly middle-of-the-range-politically, intelligent, sane westerners.", or in reality probably some group that has that group roughly as a subgroup.
And there is a reason to think that on many things, those who share both my genetics and culture will be a lot like me, sufficiently so that I don't have much to fear. Though, there are some scenarios where there would be divergence.
The Open Thread posted at the beginning of the month has gotten really, really big, so I've gone ahead and made another one. Post your new discussions here!
This thread is for the discussion of Less Wrong topics that have not appeared in recent posts. If a discussion gets unwieldy, celebrate by turning it into a top-level post.