UC San Diego researchers say we’re nowhere near the “end of men,” and that to reverse gender inequality will require more than just “leaning in.”

In her new memoir/manifesto Lean In, Facebook COO Sheryl Sandberg demands that women workers take risks, seek professional challenges, and always smile during tough negotiations.

These traits appear to have propelled Sandberg, Yahoo! CEO Marissa Mayer, and 2016 presidential darling Hilary Clinton into positions of power and influence.

But these high-profile success stories conceal a hard truth: women are still underpaid and under-represented in high-powered professions, despite a recent rise in women’s college attendance.

“In our society we tend to look at the individual for explanations of success—education, hard work, moral fiber and so on,” Mary Blair-Loy, an associate professor of sociology at UC San Diego and founding director of the Center for Research on Gender in the Professions said in a press release. “Even Sheryl Sandberg’s critique is focused on the personalities and willpower of individual women. But there are also structural factors at work, not just individual.”

Blair-Loy and her research team published an in-depth study last week on the relative influence of women in law, medicine, science, and engineering.

Blair-Loy’s report lays out a sobering set of statistics: women make up only 21 percent of all scientists and engineers. In science and engineering university teaching, women hold 36 percent of adjunct and temporary faculty positions but only 28 percent of tenure-track and 16 percent of full professor positions.

In medicine, women make up only 34 percent of physicians but 91 percent of registered nurses. And in law firms, women make up 45 percent of associates but only 15 percent of equity partners.

This gender gap manifests in wage differences as well. The study authors report that among full-time workers, women earn only 81 percent of what men do, even after controlling for experience level and specialty.

In Hanna Rosin’s 2012 best-seller The End of Men: And the Rise of Women, she argues that men have utterly failed to adapt to the decline in manufacturing, construction, and finance brought on by the 2008 recession.

Service sector jobs have largely replaced manufacturing positions, and many women are making in-roads, especially at the entry level. However, there’s a big difference between a service job in retail and one in law or medicine.

According to Blair-Loy, what keeps women out of the best-paid, highest-prestige service positions is a complex interplay of gender stereotypes, rigid workplace policies, and stalled legislative gains.

“Four decades after Title IX, the low-hanging fruit is gone, and the why is complicated,” Blair-Loy said. “There are a series of interlocking factors that include workplace cultures that privilege men and cognitive biases that shape what we notice and remember about male and female workers.

“Even the most well-intentioned people among us default to cultural stereotypes—that men are more likely to be competent and professional while women are more likely to be warm and nurturing—that undermine our efforts to reward talent alone,” she added.

It’s clear that individual initiative and a greater number of college degrees will not be enough to overcome systemic inequality. Workplace policies that encourage the hiring and promotion of women and recognize their unique needs are a good first step.

“We need to make legal and organizational changes,” Blair-Loy said, “from better access to childcare and greater acceptance of flexible work schedules to more transparent hiring, evaluation, and promotion procedures.”

Today, President Obama appointment the first ever female head of the Secret Service, Julia Pierson. Women have made spectacular gains in the past few decades in terms of college admissions, pay increases, and greater “work-life balance,” but there is still a very long way to go before we can declare the battle of the sexes finished.

Note: Image courtesy of the UC San Diego Center for Research on Gender in the Professions.