It turns out that Tim Worstall, whose pithy blog I read regularly, also writes for a site dedicated to the differences between men and women, La Difference. And he's emailed me with some important observations:

[Y]es, it might be that Simon Baron-Cohen would disagree with your precis.

His research is really stating that there is such a thing as a male brain (systemizing, list making etc), the female brain (empathic) and a balanced type, and that yes, autism can be seen as an extreme form of the male brain.

However, while we might expect women to have female type brains and men male, that isn't actually the way it works out. Some 17% of either sex have the other (if that makes sense?).

Where this begins to make sense, actually become useful, is in looking at certain jobs and professions and seeing what the sexual mix is in them. If women are more likely to have female type brains, we would expect to see more of them in a highly empathic occupation like nusrsing, which indeed we do. If there are certain jobs which appeal a great deal more to systemizing traits, then we'd expect to see many more men in it. But not all one sex or the other, as a significant portion of men are empathic etc etc.

This gives an idea:

If it is true that economic models are very like maps (which Chris Dillow thinks they are) and that understanding them requires the spatial skills known to be associated with the male type brain, then we would expect to see many more male economists than female. Further, we would expect those economists who are female to display attributes of the male type brain, which in the instance of Lynne Kiesling, we do: her map reading skills are much higher than the average man's let alone woman's.

Note that a female's possession of a male type brain is nothing to do with any other male attributes. Ms.Kiesling is quite the hottie (as is Virgina Postrel, another possible data point).

If you're so minded, you can take Prof Baron-Cohen's two tests to discover if you've got a "male" or "female" or "balanced" type brain.