I've often heard LWers describe themselves as having autism, or Asperger's Syndrome (which is no longer considered a valid construct, and was removed from the Diagnostic and Statistical Manual of Mental Disorders two years ago.) This is given as an explanation for various forms of social dysfunction. The suggestion is that such people have a genetic disorder.

I've come to think that the issues are seldom genetic in origin. There's a simpler explanation. LWers are often intellectually gifted. This is conducive to early isolation. In The Outsiders Grady Towers writes:

The single greatest adjustment problem faced by the intellectually gifted, however, is their tendency to become isolated from the rest of humanity. Hollingworth points out that the exceptionally gifted do not deliberately choose isolation, but are forced into it against their wills. These children are not unfriendly or ungregarious by nature. Typically they strive to play with others but their efforts are defeated by the difficulties of the case... Other children do not share their interests, their vocabulary, or their desire to organize activities. [...] Forms of solitary play develop, and these, becoming fixed as habits, may explain the fact that many highly intellectual adults are shy, ungregarious, and unmindful of human relationships, or even misanthropic and uncomfortable in ordinary social intercourse.

Most people pick up a huge amount of tacit social knowledge as children and adolescents, through very frequent interaction with many peers. This is often not true of intellectually gifted people, who usually grew up in relative isolation on account of lack of peers who shared their interests.

They often have the chance to meet others similar to themselves later on in life. One might think that this would resolve the issue. But in many cases intellectually gifted people simply never learn how beneficial it can be to interact with others. For example, the great mathematician Robert Langlands wrote:

Bochner pointed out my existence to Selberg and he invited me over to speak with him at the Institute. I have known Selberg for more than 40 years. We are on cordial terms and our offices have been essentially adjacent for more than 20 years.This is nevertheless the only mathematical conversation I ever had with him. It was a revelation.

At first blush, this seems very strange: much of Langlands' work involves generalizations of Selberg's trace formula. It seems obvious that it would be fruitful for Langlands to have spoken with Selberg about math more than once, especially given that the one conversation that he had was very fruitful! But if one thinks about what their early life experiences must have been like, as a couple of the most brilliant people in the world, it sort of makes sense: they plausibly had essentially nobody to talk to about their interests for many years, and if you go for many years without having substantive conversations with people, you might never get into the habit.

When intellectually gifted people do interact, one often sees cultural clashes, because such people created their own cultures as a substitute for usual cultural acclimation, and share no common background culture. From the inside, one sees other intellectually gifted people, recognizes that they're very odd by mainstream standards, and thinks "these people are freaks!" But at the same time, the people who one sees as freaks see one in the same light, and one is often blind to how unusual one's own behavior is, only in different ways. Thus, one gets trainwreck scenarios, as when I inadvertently offended dozens of people when I made strong criticisms of MIRI and Eliezer back in 2010, just after I joined the LW community.

Grady Towers concludes the essay by writing:

The tragedy is that none of the super high IQ societies created thus far have been able to meet those needs, and the reason for this is simple. None of these groups is willing to acknowledge or come to terms with the fact that much of their membership belong to the psychological walking wounded. This alone is enough to explain the constant schisms that develop, the frequent vendettas, and the mediocre level of their publications. But those are not immutable facts; they can be changed. And the first step in doing so is to see ourselves as we are.