That's not the issue.
The issue is when the next logical step is claimed to be that women (or men) are therefore less suited to certain opportunities, and that trying to balance this inequity is simply a desire to bow at the altar of "political correctness."
Joe's bell curves are nicely illustrative, but they are addressing the argument at the extremes, where perhaps these innate differences DO manifest into distinct differences. Thing is, extreme circumstances make for bad law, or something along those lines. The vast majority of us operate in the middle by definition, where even the bell curve enthusiasts are forced to admit that the differences in application are minor. So when there's an initiative to get more women into STEM, for example, it's not addressing the outliers at the end (no one would have denied Stephen Hawking a spot on the podium in the interest of gender diversity), but rather the middle positions where institutional issues make the ratio 90/10 instead of a natural 45/55 or whatever.
This is just not the way that those bell curves should be looked at. I would agree that for most interpretations, working in the extremes or only looking at them would not be correct. But this situation is different and partly the reason why you are having a false interpretation of these curves is that I did not fulling explain them. So lets post them again this time and describe what each side means.
When it comes to interest in work, working with people vs working with objects are opposites. So, in the graph, the far left side of the curve are filled with people who really like working with people above all else. The far right side are those whom really enjoy working with objects. The middle are those benevolent souls who are not one way or the other, or maybe only by a bit. As you can see, the graphs overlaps but are slightly off. The female graph trends to the left and the male graph trends to the right.
(By the way, if you have any doubt these slight differences exist biologically, it has been proven ... by studying females who were victims of Congenital Adrenal Hyperplasia, a situation were higher amount of male hormones were present during gestation, and comparing them to their unaffected sisters. Since you are comparing two sisters whom were raised by the same parents in the same socialization, all factors are reduced greatly except biology. So the differences have to be biological, especially if you find this to be the case across a sample of 125, which is how big the study was. If you think 125 is small, for many medical studies it might be. But we are talking about a group of people whom you can only be sure were affect by this by analyzing the embryonic fluid through out the pregnancy. After birth, it is impossible to determine if someone was affect by CAH, and the fact is that not too many mothers would be open to constantly have their fluids tested. So there are not a high number of known test subjects out there to look at. Also, a properly sourced random sample of 30 will generate an accurate view of a population, so 125 is certainly a large enough group.)
And in both extremes, the corresponding gender has a much greater representation then by how much the average is off by.
Now, the question is what type of careers will fall towards either end and what towards the middle?
You mention that since most of us fall in the middle, only looking at the extremes would not make sense. I would agree with you if the only careers that existed were those at the extremes. But what you fail to recognize is that most jobs fall in the middle too. So for the most of us middle of the road people, on which the majority of both genders are, there are a very large amount of jobs that would fit the interests of the middle of the roaders. So it is with these jobs most people find themselves in. However, the jobs that are very people oriented or very object oriented are at the extremes and thus would only attract those at the extremes as well.
Jobs like programming or nursing.
So when looking at these jobs that fall at the extremes it makes perfect sense to think about those people at the extremes as filling them. So, case in point, looking at the ends of the bell curves for interest when looking at jobs that also fall at those ends is the correct thing to do.
In a response to you first statement about next logical steps, this is just simply not the case nor what I advocating. As was pointed before, I am merely talking about interests and not ability. They are unrelated and just because you may not be interested in doing something does not mean you will be bad at it, and of course vis versa. So using this data as a reason to discriminate is just wrong and inappropriate. This is not what I am advocating.
I am merely pointing out a difference in interests exists between genders and that is probably the main reason for the disparities. It is a result of purely innocent decisions made on a personal level in regards to what career path that individual wants to follow. And to imply that in today's political correct world, were companies are bending over backwards to hire women at all costs but still can't fill the quotas, that there exist some underlying sexism keeping women back just makes no sense.
