Did the study take 1,000 babies, male and female and raise them from birth in a completely neutral environment without any stereotyping whatsoever? If not, the subjects of the study were already tainted by sociological influences. So if women are given to believe that they are less capable of mathematic or scientific achievement, chances are that few will reach for that carrot. In fact, excessive displays of intellect or talent have historically been discouraged in females. That might tend to skew the results of any such study. Variability theory in males is not a new area of study. It goes back to Darwin. It is also highly disputed wrt human beings on the basis of environmental factors.