When it comes to disparities in gender among various, there are no limits to the hypotheses laid out to explain differences, usually in sync with the cultural agenda of the proponent. Engineering, for example, pays women more equally than any field in America but has far fewer women than environmentalist groups, which pay women about $.70 compared to men - yet engineering is criticized for having fewer women. Medical doctors have equal representation while the social sciences have fewer men and the hard sciences have fewer women.

University of Washington psychologist Sapna Cheryan and colleagues instead believe women are more sensitive about media stereotypes. She and colleagues studied whether the stereotypical view of the geeky male nerd so often portrayed in the media, like CBS's "The Big Bang Theory," discouraged women from pursuing computer science degrees. Computer science isn't science per se, and the characters on that show are two particle physicists, a theoretical physicist, and an engineer - the supporting cast contains a microbiologist, a neuroscientist and a waitress. No computer scientists. But if you are going to get surveys of undergraduates into a paper, it helps to have a topical hook in the press release.

Science, technology, engineering and math – STEM careers – has gotten billions of dollars in Federal money for marketing, yet women remain underrepresented in some of them, especially computer science. The question then becomes: Are women just not interested in that field of work, or is something else keeping them away? Advocacy groups will insist it is entrenched sexism while Wikipedia, where gender is not known and users are anonymous but are obviously computer-heavy, have far more men than even computer science, according to their internal surveys.

It may be that perception matters more to women than men. So Cheryan and colleagues conducted two surveys. First, they asked undergraduates from the UW and Stanford University to describe computer science majors.

They found students who were not computer science majors believed computer scientists to be intelligent but with poor social skills; they also perceived them as liking science fiction and spending hours playing video games. Some participants went so far as to describe computer scientists as thin, pale (from being inside all the time), and having poor hygiene.

"We were surprised to see the extent to which students were willing to say stereotypical things, and give us very specific descriptions. One student said computer science majors play 'World of Warcraft' all day long. And that's a very specific, and inaccurate, thing to say about a very large group of people," Cheryan said.

However, women who had taken at least one computer science class were less likely to mention a stereotypical characteristic. There was no difference in men's descriptions, whether or not they had taken a computer science class.

In a second experiment, they asked male and female participants to read fabricated newspaper articles. One article claimed that computer science majors no longer fit those stereotypes, while the other article claimed they actually do reflect those stereotypes. The articles were identical except when claiming the field did – or did not – reflect the stereotypes. Students then rated their interest in computer science.

Men were unaffected by how computer science majors were represented, but women who read the article with non-stereotypical images were significantly more interested in majoring in computer science than women who read the article with gendered stereotypes.

"It doesn't take much to change these stereotypes. We gave them a very short article, and we were able to shift their thinking about computer science," Cheryan said of the female participants. "Our message is not that the people in computer science need to change. It's a marketing issue. When students think of computer science, they think of all these stereotypes that are not accurate. If we could expose students to what computer scientists are really like and all the varied and interesting things they do, we can have a positive effect on participation in the field."

Published in Sex Roles with Caitlin Handron and Victoria C. Plaut and Lauren Hudson from the University of California, Berkeley. Cheryan also co-authored a paper in Sex Roles on precluded interest, which sought to explain underrepresentation in men in the humanities and social sciences, along with women in some fields of science.