I think of rationality as a kind of discipline more than an inborn trait, per se. It's a habit of consistency between thought and action. I think that if women are perceived as more irrational, it is because they are devalued in thought or action, making it seemingly not worth the trouble to acquire the skill of aligning the two.
It comes down to incentives. Traditionally, women were encouraged to maximize their interest in only certain areas of the private sphere, and largely dis-empowered elsewhere. The notion of the "irrational" women is basically emblematic of not only the limitation of her agency, but also a means by which to undercut the areas where she might apply herself. That covers emotional labor or nearly anything else that prioritizes the interests of the collective--whether it be her intimate relationship, her family, or community--above that of the individual.
On the flip side, the social consequences to a man for
not exhibiting rationality as I've defined it were and are severe. A man incapable of acting in way consistent with his
own goals is essentially a man without integrity. It reveals the double bind for women, though. In order to be respected for her rational capacity, she has to behave in a way that puts her outside the expectations of her sex.
So to answer your question, [MENTION=8413]Zarathustra[/MENTION], the average woman is most likely less rational than the average man, not because of anything inherent to her capacities, but because the society is more permissive of it. While fully acknowledging the political context of the thread, I'd venture to say a more interesting question to explore might be would the woman feel as entitled to act like a crazy bitch if she felt more personal agency? If she felt more agency, would it increase her sense of personal responsibility? And if she felt a greater sense of personal responsibility, would her actions not in turn be more rational?
ETA: Conversely, we could all just let our freak flag fly, and just have an
exquisitely nice time of it.
