I heard recently (maybe on BBC R4?) a suggestion that the increase in cases of AS and autism, although partly due to fewer undiagnosed cases, is also partly real. As there are more successful nerds (for want of a better word) like, er, me for instance -- having computer skills which didn't exist a generation ago -- who are less good at social interaction, they tend to marry each other. The combination of "nerdy" genes is likely to result in "nerd-squared" children. I'm being deliberately simplistic here, but you can follow the reasoning.

My other half is talented in wildly different directions from me, so our kids are creative and bright, but much better with their social skills than me, thank goodness. On the other hand, I don't believe we can take much blame or credit for the inherited characters of our kids: you'd have to have a great many children to make up a statistically meaningful sample.

Steve