Here is what I have seen............
Thin, good looking women dressed in the latest fashion generally improve quickly. If they wear red fingernail polish and heels, the improvement is even greater. Overweight frumpy women do not improve nearly as quickly if at all. Everyone remembers Miss Fashionable and everyone forgets Mrs. Frump.
I do not believe this improvement, although I have seen it, is a product of the woman, or how she recieves instruction. I believe it is a product of how the instructor provides instruction, and the instructors do not want to admit this.
In the pre-range safety lecture with new shooters, this idea of expectations is generally disseminated to the pupils. The cute women smile, the men start to get pissed. The stage is set for propogation of a fallacy. At the range the instructors generally align themselves near Miss Fashionable. Whether it is to be ready for a turning muzzle, or to get a better view is irrelevant. Miss Fashionable gets more attention as a result. The men see this, and begin to tune out the instructor. The fact is, if the instructors were all women, you would see the reverse effect, with the old geezers out shooting everyone. Want to see it happen? Attend one of Kay Clark's classes.
When it comes to shooting, and learning to shoot, men and women have the same level of ability given the same eyesight, motor skills and intelligence. As soon as they enter that class though, the bias and prejudices of the instructors begins to take hold, and it is accepted as gospel truth. Any man who has attended a class with two male instructors, four good looking female students, two men, and an elderly woman know exactly what I am saying.
When instructors find these results, they need to look inward.
The level of improvement in any student of any endeavor depends on two factors, the ability of the instructor to communicate what is to be taught, and the receptiveness of the student to that instruction. All students enter a class receptive to instruction. If that were not the case, they would not be there at all, would they? Some classes, such as at a police academy and CCW classes may be an exception, but in a voluntary class, this is always the case. Then within the first hour, or during the first break, the instructor begins to separate out the expected ability of his students based on nothing more than his own prejudices. The students have spent this time fearing they might fail, unsure if they will perform adequately, and wondering who will do best, and who will do worst. Then the instructor, the one who instructs, unleashes this "women shoot better" idea. The events that follow and how everyone views them are thus preordained.
Nomex on.
edited to add: Heck, we see the same thing on this forum. A male newbie comes along and posts a question about being new to shooting, and wanting to learn. He gets two encouraging responses, three flames, one criticism of his grammar, and the thread dies.
A newbie poster with a name like MissRedHot makes a post about being a new shooter and she gets over 30 responses of encouragement, ten invitations to go shoot, she is told she will outshoot everyone in two weeks, and the thread continues until it is revealed the ISP is the same as the first poster. Don't laugh. It happens on almost every forum.