I still feel quite confident that LessWrongers are likely, and more likely than the general population, to accept said value claim
Oh, sure, the surveys will tell you so directly.
But "more likely than the general population" is pretty far from "doesn't apply to the 10% of you who are egoists".
I'm currently unconvinced either way on this matter. However, enough arguments have been raised that I think this is worth the time of every reader to think a good deal about.
http://nothingismere.com/2014/11/12/inhuman-altruism-inferential-gap-or-motivational-gap/