I'm part of a lot of communities, and clearly HN is one of the rare where I am, more often than not, answered in comments by people more intelligent than me. So even if I'd consider myself an average Joe, it seems a good sign that HN has quite a lot of intelligent people. At least more than average.
While I cannot be certain that a randomly selected HN participant is above average intelligence, the average and is clearly is at least 1 SD above average, and the median is not 100. The quality of posts, in-depth knowledge expressed, nuanced, fluid, and flexible thinking, makes this a community in which I wish to participate, and this is coming from someone who frequently communicates with academic researchers and intellectuals in his daily life.
"but if you can’t reasonably quantify it based on anything empirical,"
Simply the writing quality, grammar and sentence structure of the comments on HN would easily be enough to prove that HN readers (well, commenters) are above average.
I spend enough time glazing over headlines, stories and comments from other sites out of casual interest and I'll bet any amount of money this is true.
Maybe it’s also the culture around here. I’ve seen a few casual lololol comments that get downvoted a lot, so it creates an impression that if you’re going to say something, at least do it stylishly. (Of course value is important too..)
I like HN, but can’t see it as a social space like most forums are. (And yes I like HN for that reason too!)
