Sylvia Ann Hewlett had a piece in the Financial Times this weekend highlighting a study she co-authored (called "The Athena Factor" published in the Harvard Business Review) about how women tend to drop out of the science industry, especially in a corporate setting. Many cite factors such as isolation, like being the only woman on a project, and what Hewlett calls "male behaviour" since "63 per cent of women in science, engineering and technology have experienced sexual harassment." The fact that women aren't as prevalent in science as they could be isn't a new idea. I reported a story about female academics in hard sciences last year for Campus Progress.
One of the greatest factors really can be a lack of mentorship. When a woman feels isolated by being the only woman on the team, and there aren't any strong mentors in the company that they can turn to because other women have "dropped out" the job itself becomes very demoralizing, even if it's in a field that these women have chosen to dedicate their lives to. One thing I discovered while reporting the story was a book written by Ellen Daniell called Every Other Thursday, in which women in the hard sciences found each other and formed a group to help each other stay focused, vent about sexist shit that happened in their department, or just encourage each other in their personal lives. The women in the book really found their own kind of mentorship that they just weren't getting from other people in their departments. Those kind of relationships shouldn't be taken for granted.