I am female and have worked in computer science since the government first forced corporations such as AT&T to start considering women as candidates for technical jobs (back in the early 1980's). My specialty in college was computer hardware and operating systems--programming close to the metal, or what you might call embedded software. I was valedictorian in high school (out of 500 people), was a National Merit Scholar, and a Fulbright Scholar.
In computers, when you get closer to hardware, there are fewer women to start with. Usually, there have been anywhere from 5 to 15% females in my work groups, but over 30 years, this percentage has not increased and in fact has been actively decreasing.
Here is just a small sampling of things I have encountered over the years that might cause women to leave my profession:
1) In meetings, I make a suggestion. No one responds. Sometime later, a male makes the same suggestion, and the supervisor says, "Good idea!".
2) In social situations, colleagues remarked (without knowing anything about my actual abilities), "You were just hired to fill a quota."
3) In a meeting, I interrupt someone who has gone on a long time (who has previously interrupted me), and I'm told, "You interrupted me."
4) Someone asks me a question, and a man sitting next to me answers the question for me before I can open my mouth.
5) My software isn't interfacing correctly with a male colleagues software. When I arrive at work, they are awaiting me, and the first thing I hear is, "There is a bug in your software." I listen to them for 2 minutes and explain to them why the software is not responding. The error was in my male colleague's software (he had failed to read the interface specification). No one apologized for jumping the gun.
6) I go as the lead presenter on a sales team to a group of engineers in Bell Labs at Denver. We walk into the meeting room, and their chief engineer asks me to get coffee for him (and calls me "honey"). My group (all men) regard me in stricken silence. I get the man his coffee, and then I stand up and start the meeting.
7) In almost every venue, programmers and system administrators are spoken of as "guys". If I object, I'm told that I'm a wet blanket and should get over it.
8) During a social luncheon with colleagues, a male colleague tells a sexual joke about a man being serviced by oral sex by a woman. My male colleagues laugh. I am silent.
9) One year at Bell Labs, I received a low performance review and when I asked why, I was told that "You made errors." I asked what errors. I was shown a memo that I had written and was told that a certain sentence in the memo was incorrect. I looked at the supervisor and said, "You signed this memo after I wrote it. Did you get a bad performance review?" I didn't even believe that the memo contained an error. I asked, "Do you have any other instances of my having 'made an error'? And, who said this about me?" He had no answer, but my performance review was not revised upward. I concluded, after much thought, that the supervisor wanted to fire me because I had officially reported an egregious case of another woman being sexually harrassed (worse than anything I've reported here) on the project where we both worked. I transferred laterally within the company to escape from this supervisor.
10) The company's attorneys forbade me to speak to the woman whose harassment case I reported on. However, after she and I had both transferred to another part of the corporation, we became lifelong friends. (See, good things sometimes come out of tough times).
In recent years--now in my fifties and having continued to work hard, study, learn and deepen my experience in the profession--I ended up teaching computer science course at the University of Pennsylvania for a few years. When I started teaching (in 2002, I think), I assumed that most of this kind of behavior was now old hat and didn't happen any longer, and I made a point of never mentioning anything about gender to any of my classes or to students, especially females, in counseling sessions.
After graduating, however, a number of my former students who were female eventually reached out to me privately and asked me about certain experiences they had encountered on their jobs. Had I ever experienced anything like that, they asked? And so THEN we talked.
Now--most of my male colleagues are wonderful and would never, ever do anything like the things I have mentioned above. On the other hand, if these things happen when they are present, those same male colleagues have often given a green light to the behavior by remaining silent and acting as if there is no problem. Because FOR THEM, there was not a problem. But there is. I've found over time that the same kinds of bullies who target women for abuse--and they mostly know they are doing it--do so because they think that the women are weak and have no allies in the workplace. And as such, they also will target any male whom they consider to be poorly connected or less well regarded or weak.
So allowing that kind of thing to go unmentioned, unaddressed, and so forth, does make things worse for everyone. It affects productivity. It affects people's ability to earn a living for their families. It's just plain bad. And it does still happen.
I wouldn't change a thing I've done. Although I had little mentoring and had to learn a lot of the things I now know the hard way, I love computers and I've loved being able to work with them for so long, and sometimes, I'm great at it and that is satisfying.
Young women should not be deterred at all from entering technical fields despite all this. One thing I hate to see is parents who buy their sons computers and encourage their daughters to dress provocatively and paint their fingernails instead. It starts early in life, and it's everywhere, the signs of gender difference that are mostly all unnecessary if not useless, as far as I can tell.
Marissa Mayer's book about "bearing down" (or whatever it's called) is annoying to me in particular. Bear down my ***. Just bear it and keep on keeping on, I say. And tell the truth about what it's like--otherwise, things will never change. Her book is insulting because it makes it seem like women aren't really serious or aren't trying hard enough (excuse me, we've tried our guts out).