But Carrier, like many female engineers and scientists I've spoken to over the past five years, was frankly puzzled about why anyone might see her as a victim. All along she has felt her choices were entirely her own. She always liked math and was encouraged by her parents, especially her father, who also likes numbers, to study Pure and Applied Science. Then she went into a Forestry program, but she switched out of that because "it was too touchy-feely. It was like, is this environment good for squirrels? I needed to go into something where there's a right answer." So she transferred into agricultural engineering, and told me she enjoyed it immensely---the university program, as well as the work that came afterwards. So, what about the AAUW's conclusion that women avoid studying engineering because role models are scarce, and university programs are hostile to women? "Hostile environment? Not at all. We had excellent professors. Many female professors, too." There were also many other young women in the program, she said, because students could specialize in food or water treatment and most of the women planned to work in the developing world. Not Carole. "From university I went to work at a cement company because of my love of heavy machinery. They have their own open pit mine, and it was fantastic! I loved every minute of it. I loved the work, and the people there. We worked extremely well together. I started out as a mechanical engineer working on reliability issues, then worked on production, then on machinery output." The company was good at staff development, offering courses and the opportunity to advance, she added, and she "mixed well" with employees, and was well-liked, especially on the shop floor, where she considered other employees' real life expertise as instructive as her academic training. She even had an octengenarian male mentor. Hers seemed like an unequivocally happy story, so thin on the ground these days.

Still, before too long Carrier had handed in her resignation. Why? It turned out that her employer had offered her a promotion, but company policy stipulated that professional staff had to relocate in order to advance. "They wanted to ship me to Albany. Then after that they wanted me to go somewhere else. And I thought, uproot your entire family for a few more dollars? No thanks. I love my city. I love my mom and dad, who live here too. So, no."

The yawning gap between Carrier's expectation of her career -that it could be combined with a stable and fulfilling personal life---and the reality of the lockstep, geographic moves expected in most engineering and computer firms (not to mention academe), is just one of many explanations for the STEM gender gap that is missing from the AAUW report. Though it weighs in at over a hundred pages, the report trains its sights on the suggestion of subtle, hidden stereotypes, and rarely questions how many women are actually that keen to sign on to all aspects of "male-typical" STEM careers; to wit, frequent moves, prioritizing salary and promotions over personal happiness, or sacrificing one's deep interests in other fields, say in history, human development, or public policy---all in order to fix, sell or distribute widgets, or, as one disgruntled female engineer put it, to spend the best years of one's life planning air conditioning ductwork for luxury condos.

Starting from the assumption that anything predominantly "male" is the desirable standard, the AAUW report never questions why women should choose technical fields over other disciplines, except to echo the sixties era notion that any ratio that tilts towards male must reflect something worth having. It does state, reasonably, that women in STEM careers have the opportunity to earn more, quoting as evidence the starting salary of a mechanical engineer ($59,000), versus the starting salary for someone with a bachelor degree in economics (just under $50,000). What the authors leave out is that several non-STEM careers where women now predominate pay nearly twice this much. The median salary of first-year lawyers---60 percent of whom are now women-- is $110,000, whereas recent medical, veterinary, or pharmacy graduates, the majority of whom are also women, earned over $150,000 in 2008, according to the US Bureau of Labor Statistics. In any case, for most women career decisions are not all about money, according to research by the American economist, Sylvia Ann Hewlett, and population studies by the British economist, Catherine Hakim. For 75 to 85 percent of women, other values came first, such as flexibility, autonomy, the ability to make a difference, or to work with people they respect. These values--- more than a chilly university climate-- are often what motivate them to avoid or exit physical science careers. One woman in her early forties who was among the top 10 percent of students in her university engineering class, told me she was cheered on by her engineer father and male science professors ("Ninety-nine percent of my professors were great," she told me), and enjoyed a full-speed-ahead engineering career for over a decade.... until a cancer scare got her acquainted with her priorities in a jiffy. "I just got tired of mixing petrochemicals and debugging software" she told me when I asked why after such success she radically changed tacks. "I wanted to spend more time with people I love. I like how I now get to manage my time."

The decades-long, longitudinal research project on gender differences in career motivations across the lifespan, by research psychologists Camilla Benbow and David Lubinski, is another area this report omits. A person's genuine interests play a role in what they choose to study, including the nature and breadth of the questions one gets to ask, in the lecture hall and ever after. My own field, psychology, is broad enough to allow me to draw on biology, economics, neuroscience and literature, among other interests, and the fact that computing theory, or materials science doesn't enter into that mix is a matter of choice, not hardship. As a woman picking social science as my area of study I am hardly alone. Three quarters of the graduate students in psychology are now female, as are most of the professors, and the social scientists who wrote the AAUW report have similar backgrounds. Its three authors, Catherine Hill, Christianne Corbett, and Andresse St. Rose, have advanced degrees in public policy, cultural anthropology and education, respectively, and 12 of the 15 female members of its advisory committee are social scientists with PhDs in psychology or education. Not, as Jerry Seinfeld would say, that there's anything wrong with that.

In fact there's good evidence that on average, women choose different disciplines than men do--or in different proportions--and they do so with their eyes and options open. While some women are like Carole--they feel confident about their math skills and just love big earth-moving machines, there are many other women with a math and science bent whose career choices and achievements are invisible in this AAUW report. What about Margaret Chan, the head of the World Health Organization and arguably the world's most powerful public health official, or all the other talented women who go into biology, medicine, dentistry, ecology, pharmacology, neuroscience, or veterinary science, all science programs that were mostly male forty years ago, but are now dominated by women on every university campus? Do the women really choose these fields over physics and engineering because they've been convinced by subliminal forces that their math skills are sub-par?