Comment by godelski

  > say the top ranked CS school

I've worked with and written papers with enough people from top ranked CS schools (multiple from top 5 on csrankings) while I was at a top 100 and it is a very mixed bag. There were plenty of idiots in the top 5 and plenty of geniuses in the top 100s.

I'd agree that average shows a difference but I don't think it is nearly as big as people act. Even the intra-university variance isn't what people would think (top universities have a very narrow distribution while lower ranks have wider). The trend follows, but the variance of the variances is not that large.