A new study of 21 different nations has found that the male dominance of computer science at university level is pandemic.

At first glance the study looks to be yet more confirmation of what we already know. However, it gets more interesting. Differences between the countries indicate that women might not be genetically predisposed to shun all things high tech, and that there might be other factors at work.

The study, co-authored by Maria Charles, professor of sociology at the University of California and Karen Bradley of Western Washington University, found that men are over-represented among computer science graduates everywhere, but the degree of over-representation varies by as much as a factor of three.

So what is behind the variation? Turns out, it is not what you might expect.

Girls' higher achievement in maths or science did not seem to be related to the number of graduates, nor was cultural support for equal opportunities a good predictor of which countries had the most women Comp Sci graduates.

In Turkey, for instance, for every woman Comp Sci graduate there are 1.79 men, while at the other end of the scale, in the Czech republic men graduates outnumber women by 6.42 to one [perhaps they're all working as super-models and will return to their computing education at a later stage - Ed]. South Korea and Ireland also have more relatively high numbers of women graduating from computer science courses, but, like Turkey, neither of these nations is especially renowned for taking a hard line on sex equality.

Instead, it seems that restricting the choices available to adolescents, and making it mandatory for all pupils to study maths and science subjects throughout their secondary education, correlates with a higher proportion of women going on to study computer science at university.

"The principle of being free to pursue your preferences is compatible and coexists quite comfortably with a belief in essential gender differences. This essentialist notion, which helps to create what it seeks to explain, affects girls’ views of what they're good at and can shape what they like," said Charles.

She goes on to say that the implications for policy are clear: rather that letting kids discard subjects too soon, governments should insist on more maths and science for everyone, for longer.

"As other research has repeatedly shown, choices made during adolescence are more likely to be made on the basis of gender stereotypes, so we should push off choice until later," she concludes. ®