The Game by Neil Strauss, the notorious chronicle-slash-manual of the "art" of pick-up artists. I've often thought about it since, so I thought re-reading was worthwhile.
The book is like the equivalent of Watching The English but for (American) men - an inside view from an outsider. Norah Vincent spent a year disguised as "Ned", in largely exclusively male environments (including bowling leagues, strip clubs and a monastery) and also in mixed environments (for example, dating) as a man. She discusses and make contrasts between the way men behave amongst themselves and received women's wisdom about how and why men act; and between women's assumptions about men's motives and what she discovers to be their real motives.
Since Norah Vincent is a journalist, this is an account of her journey and resultant opinions rather than anything scientific (is the latter even possible in this context?), but nevertheless she reaches the only reasonable conclusion: whatever generalisations, simplifications and stereotypes women and men hold about each other are both right and wrong. Or, to put it another way, it's not that simple. Yes, the stereotypes exist for a reason. No, that's not the whole story. Duh.
The book struggles a bit with length, since the material doesn't quite stretch, but it would be too much for a Sunday supplement article. Still very interesting. Now if only someone would do it the other way round!