Here's a key reason why girls and women shy away from careers in computer science - environment.
According to a study, the stereotype of the nerdy computer scientist who stays up all night coding and has no social life may be driving women away from the field.
This stereotype can be brought to mind based only on the appearance of the environment in a classroom or an office.
"When people think of computer science the image that immediately pops into many of their minds is of the computer geek surrounded by such things as computer games, science fiction memorabilia and junk food," said Sapna Cheryan, a University of Washington assistant professor of psychology and the study's lead author.
"That stereotype doesn't appeal to many women who don't like the portrait of masculinity that it evokes," she added.
Such objects help create what Cheryan calls ambient belonging, or the feeling that you fit or don't fit in somewhere.
"It is the sense you get right away when you walk into a room. You look at the objects and make an instant appraisal of how you would fit with the objects and the people who are typically found in that environment. You also make a judgment of 'I like it here' or 'I don't belong here,'" she said.
Cheryan conducted four experiments involving more than 250 female and male students who were not studying computer science to look at possible reasons why the proportion of women in the field is dropping while the proportion of women in such disciplines as biology, mathematics and chemistry is increasing.