This also explains a lot of things. People regard IQ as if it is meaningless, just a number, and they often get defensive when intellectual differences are acknowledged. I spent a lot of time doing research on adult giftedness (though I'm most interested in highly gifted+ adults) and, assuming the studies were done in a way that is useful (I've heard there are problems with this), and my personal experiences talking to gifted adults are halfway decent as representations of the gifted adult population, there are a plethora of differences that gifted adults have. For instance, in "You're Calling Who A Cult Leader?" Eliezer is annoyed with the fact that people assume that high praise is automatic evidence that a person has joined a cult. What he doesn't touch on is that there are very significant neurological differences between people in just about every way you could think of, including emotional excitability. People assume that others are like themselves, and this causes all manner of confusion. Eliezer is clearly gifted and intense and he probably experiences admiration with a higher level of emotional intensity than most. If the readers of LessWrong and Hacker News are gifted, same goes for many of them. To those who feel so strongly, excited praise may seem fairly normal. To all those who do not, it probably looks crazy. I explained more about excitability in the comments.

I also want to say (without getting into the insane amount of detail it would take to justify this to the LW crowd - maybe I will do that later, but one bit at a time) that in my opinion, as a person who has done lots of reading about giftedness and has a lot of experience interacting with gifted people and detecting giftedness, the idea that most survey respondents are giving real answers on the IQ portion of the survey seems very likely to me. I feel 99% sure that LessWrong's average IQ really is in the gifted range, and I'd even say I'm 90%+ sure that the ballpark hit on by the surveys is right. (In other words, they don't seem like a group of predominantly exceptionally or profoundly gifted Einsteins or Stephen Hawkings, or just talented people at the upper ends of the normal range with IQs near 115, but that an average IQ in the 130's / 140's range does seem appropriate.)

This says nothing about the future though... The average IQ has been decreasing on each survey for an average of about two points per year. If the trend continues, then in as many years as LessWrong has been around, LessWrong may trend so far toward the mean that LessWrong will not be gifted anymore (by all IQ standards that is, it would still be gifted by some definitions and IQ standards but not others). I will be writing a post about the future of LessWrong very soon.