Gender equality?

Since I got my copy if Bushido in the mail a few days ago, I have been studying FGU rules. This got me thinking. There was a time when it felt like all games was very much about simulationism. I don't mean that specifically in the way Forge people do, just that the idea that rules should cover all bases and make it feel real.

I have gotten the impression that one very common rule back then was to give females higher dexterity than males.

Since I have been starting a exercise program, focusing on stretching and muscle building, thoughts on my own stiffness is very common in my mind. Naturally, I wonder if this is somehow related to my maleness? Is it really so that women are more agile than men?

While it's quite easy to understand why a penalty to strength is common for females, I wonder if the bonus to dexterity is there only to balance the penalty or it it's there for a "simulation" reason, if you see what I mean?

My wife thought it was just a question of game balance. For her it didn't make sense that women should be more agile, just because of their sex. She is far less stiff than I am, but extrapolating from us two seems silly. I guess there might be some facts out on the web, but finding it? Don't get my started on how to verify your sources on the net...

If this isn't a rule grounded in anatomical truths, I wonder how many other rules "simulating" reality is also pure game artifacts?