US researchers have issued a comprehensive roundup of research covering that hotly-debated topic: Why aren't there more girls in the sci/tech/engineering/maths-based world?

In broad outline, the Cornell Uni team of psych specialists (one male lead author, two female co-authors, hem hem) say that the consensus of science suggests that men's possible biological advantages in maths-based areas could well be a factor in the lack of girls. But that isn't enough of a factor to fully explain the almost total absence of women from such fields.

According to the new paper, Women's Underrepresentation in Science: Sociocultural and Biological Considerations, men in general aren't all that much better than women at maths. But at the high end of ability, especially in spatial and mech/electronic geek type reasoning, there are a lot more chaps:

For both spatial reasoning and mathematics, males are between 1.5 and 2.3 times more likely to be at the high end of the score distribution (including in some analyses >7 times more likely to be at the top 1%). Where males are hugely overrepresented at the high end is in areas of mechanical/electronic reasoning (by a factor of nearly 10 to 1).

But all that said, women today are much more present at the higher end of so-called STEM work (Science Technology Engineering and Mathematics) than they were: though a lot of the female inroads have been made in areas that aren't really very techie or maths-y.

In addition to their impressive gains in high school and college, women are increasingly attaining doctorates in STEM fields: By 2001, women earned 36.6% of PhD degrees in scientific and engineering fields, up from just 8% in 1966, though disproportionately more were earned in less math-intensive fields, such as the social and biological sciences (43.5%– 67.1%). Still, women have made impressive gains in attaining doctorates in math-intensive fields as well, obtaining 29% of the PhD degrees in mathematics, 17% in engineering, and 22% in computer sciences. Women’s successes have been even greater in other scientific fields, where they have obtained 50% of medical doctor (MD) degrees, almost 75% of doctor of veterinary medicine (DVM) degrees, and 44% of PhD degrees in biological sciences.

The researchers say that it's important not to make too much of the possible inbuilt differences between the sexes, saying that in fact these factors can be warped fairly easily by environment, training etc. For instance, one indicator thought by brain brainboxes to indicate STEM aptitude is the ability to visualise and understand rotations - as in engineering drawings, for instance.

But it appears that if you play enough action-oriented video games, your ability to perform this mental feat goes up - boy or girl. This may offer a clue as to why male college students seem to stay the course better in STEM:

A recent, well-controlled study found that merely playing action video games can narrow gender differences in mental rotation ... mental-rotation performance of college women who had one semester of video game training (Tetris) [was] only marginally lower than that of men who had no training (but were given repeated testing on rotation ability), and this was true regardless of pre-existing spatial experience. Perhaps with an even longer intervention, more complete gender convergence would occur.

Even if you assume that gentlemen are just better at maths than ladies are, and don't get into underlying differences like their parents not forcing little girls to play video games in their youth, females are still rarer than they should be according to the study.

"Women would comprise 33 per cent of the professorships in math-intensive fields if it was based solely on being in the top 1 percent of math ability," says Stephen Ceci, lead author. "But they currently comprise less than 10 per cent."

The research suggests a similar pattern across all STEM activities, in commercial and other non-academic contexts in Western-type societies. Ceci and his collaborators ascribe the remaining difference primarily to matters of family life, with women still taking more time out from work than men at critical times in their careers. Discrimination as such wasn't seen as so much of a factor.

There was also some suggestion that people naturally tend to drift out of the hardball end of STEM activity anyway, and that such a jump was easier and more attractive for those with the people skills at which women were deemed to excel.

"It appears that the family-career trade-offs constitute a major factor in the dearth of women in fields such as engineering, physics, computer science and in higher-level positions in non math-related fields," says Ceci. "Women who are good in math seem to have more career options. Those who are highly competent in math are more likely than men to have high verbal competence, too, thus opening up the option of going into the humanities or law, which may offer more flexibility in their career tracks."

Overall it seems the jury's still out on the underlying causes: but it may be some time before the sweaty locker-room/dungeon of the hardcore STEM geeks sees a (probably welcome) influx of females. The Cornell roundup paper was based on more than 400 previous works, comprising decades of research into the subject.

Those who fancy a proper academic punch-up should probably read the whole paper, here (pdf). ®