My general impression is that there actually two different fault-lines about race -related questions on Lesswrong.
One is: Are there biologically-determined differences in politically-sensitive traits like intelligence between races? (One should note here that a) there is more to biology than genes and b) "race" is an amorphous term and the layman's use of it based on a rough eyeballing of skin color doesn't necessarily line up well with "genetic cohort"; a desire not to have to explain these nuances over and over again is another reason for people to take the agnostic-leaning against position.)
The second fault line I've observed is about statistical discrimination -- given an individual from a supposedly "inferior" cohort who has nevertheless provided independent bits of information about their intelligence (e.g. scored far above the mean on an IQ test) , should one argue that the more individualized bits screen off whatever information one might have argued just based on their cohort, or should one privilege the cohort information and assume the individual bits of information would just regress to the mean on further investigation. (Someone who is less inclined to the former position than I am might do a better job phrasing the latter; I suspect I'm strawmanning it somewhat but I leave it to its advocates to articulate it better.)
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A note for theists: you will find the Less Wrong community to be predominantly atheist, though not completely so, and most of us are genuinely respectful of religious people who keep the usual community norms. It's worth saying that we might think religion is off-topic in some places where you think it's on-topic, so be thoughtful about where and how you start explicitly talking about it; some of us are happy to talk about religion, some of us aren't interested. Bear in mind that many of us really, truly have given full consideration to theistic claims and found them to be false, so starting with the most common arguments is pretty likely just to annoy people. Anyhow, it's absolutely OK to mention that you're religious in your welcome post and to invite a discussion there.
A list of some posts that are pretty awesome
I recommend the major sequences to everybody, but I realize how daunting they look at first. So for purposes of immediate gratification, the following posts are particularly interesting/illuminating/provocative and don't require any previous reading:
More suggestions are welcome! Or just check out the top-rated posts from the history of Less Wrong. Most posts at +50 or more are well worth your time.
Welcome to Less Wrong, and we look forward to hearing from you throughout the site!
Note from orthonormal: MBlume and other contributors wrote the original version of this welcome post, and I've edited it a fair bit. If there's anything I should add or update on this post (especially broken links), please send me a private message—I may not notice a comment on the post. Finally, once this gets past 500 comments, anyone is welcome to copy and edit this intro to start the next welcome thread.