Virginia Rometty at IBM. Marillyn Hewson at Lockheed Martin. Meg Whitman at HP. Ellen Kullman at DuPont. Marissa Mayer at Yahoo. Phebe Novakovic at General Dynamics. The presence of these women would imply that science, engineering, and technology (SET) industries welcome women.

The fact is, senior female leaders in SET industries are still too few and far between. Even as these women blast open doors and blaze trails, new research (PDF) from the Center for Talent Innovation shows that U.S. women working in SET fields are 45% more likely than their male peers to leave the industry within the year.

Women in SET in the U.S., Brazil, China, and India are committed to their work and their careers. Over 80% of U.S. women love what they do; in Brazil, China, and India, the numbers are close to 90%. Over three-quarters (76%) of U.S. women consider themselves “very ambitious,” as do 92% of Chinese and 89% of Indian SET women. At the same time, a sizable percentage of SET women feel stalled, with young women feeling particularly frustrated.

Why are women turning off and tuning out? The study finds that powerful “antigens” (PDF) in SET corporate environments block them from contributing their full potential at work. Gender bias is the common denominator, manifesting in cultures hostile to women: the “lab-coat culture” in science that glorifies extreme hours spent toiling over experiments and penalizes people who need the flexibility to, say, pick up their kids from day care; engineering’s “hard-hat culture” whose pervasive maleness makes women do a “whistle-check” on their work clothes to avoid a barrage of catcalls; and tech’s “geek workplace culture” that women in our study often compared to a super-competitive fraternity of arrogant nerds. These cultures marginalize women, making them feel isolated: 21% of U.S. women in science say they experience “lab-coat cultures”; 25% in engineering face “hard-hat cultures”; and 31% in tech face “geek workplace cultures.”

Meanwhile, SET women perceive a double standard in how they are perceived by colleagues and managers. Bias in performance evaluation is systemic: 72% of women in the U.S. and 78% in Brazil perceive bias in their performance evaluations. More than half of U.S. women and more in emerging markets work alongside colleagues who believe men have a genetic advantage in SET fields.

All of these elements sap ambition. Furthermore, a dearth of female role models and effective sponsors leaves many SET women unsure of what it takes to be a leader: 44% of U.S. women and 57% of Chinese women feel that in order to progress they have to behave like a man. “What does it take to be considered leadership material?” asks a former project manager at Microsoft. She glumly concludes, “I think you have to be a man.”

In fact, 46% of U.S. SET women believe senior management more readily sees men as “leadership material.” Stunningly, a sizable percentage of senior leaders agree, with nearly one-third of senior leaders in the U.S. and more than half in China and India believing that a woman would never achieve a top position at their company, no matter how able or high-performing.

The result: Because women don’t look, sound, or act like the alpha male, or because they lack senior-level support, women’s ideas and innovations hit a choke point. SET men are 27% more likely to see their innovative idea make it to market than women (PDF). Unable to contribute their full innovative potential, it’s not surprising that so many SET women have one foot out the door.

There are, however, promising levers for change. The most obvious solution: sponsorship. Sponsors help their protégés crack the unwritten code of executive presence, improving their chances of being perceived as leadership material. Most important to the companies employing them, sponsors help women get their ideas heard — one of the best ways to engender respect and open opportunities to promotion.

We’ve discussed the power of sponsorship in previous posts. It’s especially necessary in SET, where the misogynistic antigens are even more deeply rooted and concentrated than in other fields, making it difficult for some leaders to imagine women holding positions that for decades were dominated by white men. “A sponsor can break down the unspoken biases by advocating for someone in a nontraditional role or offering a different perspective,” explains Christopher Corsico, Boehringer Ingelheim’s global head of Medicine and QRPE.

However, the difficulties women encounter in finding a sponsor in other fields are magnified in SET. Sponsors tend to help people who remind them of themselves. However, senior SET leaders are overwhelmingly white males, making it that much harder for female scientists, engineers, and technologists to trigger that instinctive outreach. The SET fields are also made up of extraordinarily tight-knit networks — of graduates from a particular academic institution, of veterans of a famous project, or of colleagues from a specific lab. Not belonging to the right network makes it much harder to benefit from the close connections that spawn sponsorship. Furthermore, SET women overwhelmingly confuse supporters — mentors and role models — with sponsors. Consequently, they target the wrong people: people they like, rather than leaders with the power to get them where they want to go.

The demand for SET talent is intensifying: The U.S. Bureau of Labor Statistics projects that SET jobs will increase by 17% between 2008 and 2018, a growth rate nearly twice that of non-SET employment. Meanwhile, demand far outstrips supply: Tech leaders like Google, Facebook, Amazon, and Apple will need to fill more than 650,000 new jobs (PDF) by 2018 to meet their growth projections, and two-thirds of those new hires will be for SET roles. Other SET fields are also massively undersupplied: There were six health care openings for every qualified graduate and four for every engineering degree. And this is just in the United States. The situation is multiplied in Brazil, China, and India, where SET industries are the dynamos propelling these economies.

Given the global scramble for SET talent, companies simply cannot afford a drain, much less a hemorrhage, of capable women.