Personal note: I've been meaning to put together a post, but got caught up in an email exchange over natural philosophy.
Interesting result reported by Reuters: Married men earn more if wives do the chores-study (Thanks to Compuserve)
He said analysis suggests there could be two explanations for the results:
A marriage might allow a husband and wife to focus their activities on tasks to which they are most suited. Traditionally, this would result in the man concentrating on paid work enabling him to increase productivity and in consequence his wages.
Taylor said another explanation could be that marriage may increase the amount of time a man has to hone work-related skills which could trigger higher wages.
So perhaps this study vidicates the traditional husband-wife division of labor as most natural to the skills of men and women.
An interesting follow-up would study whether the wife would earn more if the husband remained at home to do chores. I would doubt it: husbands have a reputation for being inept at household tasks, so that it's not so much that men are better in the work-world, but that women are better in the home. (Chortle!)
(The deeper explanation is that men's brains are not as interconnected as women's brains and not as tightly integrated with memory and the senses. This fact makes men good at doing specialized tasks that require concentration and abstraction, but poor at more generalized tasks, such as integrating verbal and non-verbal signals to better communicate.)
Also of interest: Where the Smart Women Are
On brain differences between the sexes, there are a number of books out there. This one I've read and it's good enough to recommend:
Anne Moir and David Jessel, Brain Sex: The Real Difference Between Men and Women (Delta, 1992).