People Should Know When They're Conquered [Updated Six Times]

Or so says the Russel Crowe character in Gladiator after taking a look at the German opposition who appear to think they're still going strong. Had to think of it when I read Bryan Caplan's last post. A few days ago, he had a post comparing US women's liberties ca. 1880 and ca. 2010, for which he got torn to pieces by his commenters, many of which share his general outlook. By "torn to pieces" I don't just mean that they criticized him in no uncertain terms; it was a bit like watching Grün-Weiß Gelmer under-11s take on FC Barcelona. (You may not have heard of the former outfit. I used to play for them.)

This was the most impressive example I had ever seen of an obviously intelligent person (in the sense of "does well on an IQ test") make a complete ass of himself. Until, that is, I read his "Reply to My Critics".

As someone with an interest in psychology, I seriously wonder how such a thing can happen. All I can think of is a love of contrarianism and an infatuation with counter-intuitive claims. But surely that doesn't explain all of the mystery? Suggestions are welcome.

Added: John Holbo's reaction. The comments thread, inlcuding links to Caplan's homepage, is pretty funny.

Added (2/4): Caplan's "Further Replies" and the "Postcard Version" of his argument.

Added (3/5): Will Wilkinson's comment. And another.

Added (6): And her's Tyler Cowen.