Acouple of years ago, Harvard Business Review asked Barbara Kellerman to join an online symposium on "the future of leadership." To Kellerman, a lecturer in public leadership at Harvard's John F. Kennedy School of Government, the future looked much like the past — with most of society's powerful seats occupied by men. She let loose with what she admits was "a pretty angry blog."

Under the title "The Abiding Tyranny of the Male Leadership Model — A Manifesto," she declared, "I'm sick of hearing how far we've come" — about the isolated promotions of occasional women, about the "pipeline" of potential female leaders rising in the ranks. "The fact is that so far as leadership is concerned," she wrote, "women in nearly every realm are nearly nowhere — hardly any better off than they were a generation ago."

Only 3 percent of Fortune 500 companies were headed by women, Kellerman noted in the piece, and only six of the top 100 technology companies had female CEOs. Not quite 17 percent of members of Congress were women. The proportion of women holding statewide office had dropped from 27.6 percent in 1999 to 22.6 percent in 2009, she reported, and they constituted only 19 percent of the Harvard Business School senior faculty.

It's true that most of those statistics have been flat for a decade or so (now 18 women are at the helm of Fortune 500 companies — or 3.6 percent). Yet, was Kellerman overstating her case by saying women are "nearly nowhere"? Think of Hillary Rodham Clinton as secretary of State, and before her, Condoleezza Rice and Madeleine Albright. Two of the most powerful figures in Europe are women: German Chancellor Angela Merkel; and Christine Lagarde, the International Monetary Fund's managing director. In the U.S. corporate world, Meg Whitman ran eBay and, after losing a California gubernatorial race, became Hewlett-Packard's CEO. Other female CEOs include Virginia Rometty at IBM, Patricia Woertz at Archer Daniels Midland, Indra Nooyi at PepsiCo, and Irene Rosenfeld at Kraft Foods — all companies in the top 50 of the Fortune 500.

Alice Eagly, a Northwestern University psychology professor and leading researcher on women and leadership, takes a sunnier view than Kellerman. The Bureau of Labor Statistics reports that 25.6 percent of U.S. chief executives are women, she noted. "That number has been creeping up, [by] about 1 percentage point a year. So it's not true there is no change. There is slow change." That a quarter of all CEOs are women "is hardly small," Eagly said, pointing out that in the 1940s and into the '50s, the proportion "was probably zero."

Nor is Big Business the only place of female leadership, Eagly said: "Women have been historically attracted to public service of various sorts, and to nonprofits — where, again, they're not the majority of people at the top, but they do better than in the Fortune 500."

It was precisely the recognition of the slow pace of change that set Kellerman off. The ire in her HBR blog post, she recounted, "was, "˜You're giving me the pipeline argument — just be patient and it'll all be fine, and in the fullness of time there will be equity.' And I'm going, "˜Screw this.' Partly what I'm lamenting in that piece is the lack of a more self-conscious feminist movement where women join together and work on their own collective behalf."

Some prominent female executives, such as Xerox ex-CEO Anne Mulcahy and Sheryl Sandberg, Facebook's chief operating officer, have been saying just that. In fact, Mulcahy made headlines recently when she criticized Facebook because all seven members of its board of directors are male. "It's unfortunate when companies with a large percentage of women constituents don't reflect that in their boardrooms," she told Bloomberg News. Mulcahy has boardroom cred on the issue; she promoted Ursula Burns to lead Xerox, making her one of the most prominent African-American women in corporate leadership.

So, is the glass ceiling showing signs of shattering or still firmly in place? Eagly has argued that the "glass ceiling" no longer accurately describes the impediment to reaching the top. In their 2007 book, she and coauthor Linda Carli suggest a new metaphor. "Paths to the top exist, and some women find them. The successful routes can be difficult to discover, however, and therefore we label these circuitous paths a labyrinth," they wrote in Through the Labyrinth: The Truth About How Women Become Leaders. The usefulness of the labyrinth metaphor is that it implies complexity. Kellerman and Eagly, it turns out, agree that when it comes to gender and power, the easy answers aren't the best ones.

HOW WOMEN LEAD

What is holding women back? "The answer to your question is: How many answers do you want?" Kellerman replied. "I can give you one or two; I can give you 10. The reasons for it are extremely complicated and multifaceted, and it's not nearly as simple as some of the literature suggests."

She ticked off several of the prevailing theories, including the persistence of a "male hierarchy" and the effects of work and family policies that hinder mothers in the workplace. Some "anecdotal evidence," she said, "suggests that women by no means are particularly kind or friendly to other women," and don't help one another along like men do. And she added the possibility — which she offered as only a "politically incorrect" theory — "that women are less zealous to reach the top than men."

Eagly, too, cited the "lack of family friendliness" in the business world. "The penalties for dropping out temporarily or for part-time work, which are options that some women desire when they have children, are greater in the corporate sector than they are in other kinds of jobs." An unequal burden between men and women in sharing domestic duties can also put women at a disadvantage, especially in jobs that demand long hours and near-total commitment.

The differences between men and women in divvying up the work at home are familiar. It's when the discussion shifts to the differences — and perceived differences — between how men and women lead in the workplace that the conversation gets interesting.

In recent years, researchers have focused on how stereotypes about gender and leadership work against women. "A growing body of research points to stereotyping as one of the key contributors to this gender gap in corporate leadership," stated a 2007 report by Catalyst, a group that advocates for women in the workplace.

Three stereotypes are in play: one that defines women; one that defines men; and one that defines how a leader looks and acts. If the stereotypical view of leadership coincides with the masculine stereotype, women will be judged as lacking. In that case, women are "damned if you do, doomed if you don't," Catalyst's report concluded: Going for the "masculine" image tends to get them disliked; but if they seem too "feminine," they risk looking insufficiently tough for the job.

"Women are regarded as the nicer, kinder sex and thus have a cultural stereotype that is in general more positive than that of men," Eagly (and coauthors) wrote last year in Psychological Bulletin. But a nurturing stereotype "can come back to bite women," noted Janet S. Hyde, a professor of psychology and women's studies at the University of Wisconsin (Madison). "People react very negatively to women who violate that stereotype."

But suppose the stereotypes are mistaken. Catalyst has detected a "false dichotomy between men and women's characteristics." This premise finds support in both Eagly's and Hyde's research. In a 2005 article in American Psychologist titled "The Gender Similarities Hypothesis," Hyde suggested that most of the popular literature that focuses on huge differences between women and men — think Men Are From Mars, Women Are From Venus — aren't well supported by social-science findings.

Both Hyde and Eagly examined a broad range of psychological studies and then used statistical methods to determine the extent of gender differences. Some differences, Hyde found, can be considered moderate to large — in sexual behavior and attitudes, in athletic strength (but not flexibility), and in physical aggression. Yet, she reported that 78 percent of the gender differences studied are small or close to zero. Having looked at studies of children, adolescents, and adults, Hyde found negligible discrepancies in mathematical computation and problem-solving, in vocabulary and reading, in verbal aggression, in moral reasoning, and, notably, in "leadership style."

"There's a lot more variation from one woman to the next and from one man to the next," Hyde concluded, "than there are differences between men and women."

ANDROGYNOUS LEADERSHIP

When Harvard Business Review posted Barbara Kellerman's "manifesto," the reaction from readers was strong — and predictable. There were statements of solidarity from like-minded women, complaints about "whiny" feminists, anecdotal evidence about good — or incompetent — female bosses, and the inevitable anonymous comment that asserted, "Maybe men are just better leaders? Seems like the author is trying to go against nature and thousands of years of history."

The striking thing about such debates isn't just how emotional they are but how reflexively people turn their personal experience into generalizations. "I am a man working at a large American corporation that is over 70 percent female," wrote "Tony" in response to Kellerman's views. "It's absolutely one of the worst companies I have ever worked for," he judged, then went on to deplore "the feminization of society."

Anyone who pays attention to such a debate will notice how hard it is to discuss gender without resorting to stereotypes. Feminists have offered arguments that emphasize sharp differences between men and women in their interpersonal styles. Books such as Carol Gilligan's In a Different Voice (1982) and Deborah Tannen's You Just Don't Understand (1991) are still influential. Some of these books argue that women bring a distinct — and superior — style of leadership, such as Sally Helgesen's The Female Advantage: Women's Ways of Leadership (1990). John Gray's Men Are From Mars, Women Are From Venus (1992) was the best-selling (more than 30 million copies) promulgation of what Hyde calls "the differences model."

The feminist stereotypes — men are overbearing self-promoters and women are more caring and compassionate — imply that women bring something better to leadership than men do. Eagly doesn't reject that idea entirely, although she said the research indicates only "a small difference, on the average, [between genders], with huge variability within each sex." She and other leadership theorists like to distinguish between what they call "transformational" leaders, who try to empower subordinates and inspire teamwork, and more-traditional leaders who prefer rigid lines of authority. "The women are slightly more transformational," she said, "than the men."

Men, of course, can be "transformational," too. Gary Powell, author of Women and Men in Management, cited Alan Mulally of Ford Motor as well as Mulcahy, late of Xerox, as paragons of inclusive leadership. In Why the Best Man for the Job Is a Woman (2000), author Esther Wachs Book names Meg Whitman as a "new paradigm" leader and contrasts her with Linda Wachner, who in 1986 became the first woman to lead a Fortune 500 company. As the head of Warnaco Group, which makes women's clothing and Calvin Klein jeans, Wachner led in "a dictatorial, commanding style," Book wrote.

To the extent that an inclusive management style becomes increasingly admired, stereotypes about what makes a good leader may change more quickly — and decisively — than will the stereotypes about the nature of men and women. A "more androgynous" idea of leadership, as some observers describe it, would make it easier for women to escape double standards and double binds.

The more important point, according to Eagly, is that no credible research suggests that women do not make good leaders, even though such a bias survives. When The New York Times invited six experts to hold an online discussion in 2009 on whether women make better bosses, the 500 reader responses were full of the usual stereotypes and oversimplifications. But a few volunteered a generalization that seemed fair-minded — and plausible. "Women are no better or worse than men, in general. There are only good managers and bad managers," one wrote. Said another: "I have had good and bad experiences with both sexes. It completely depends upon the individual and not the sex."

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The author, a former editor at The Texas Observer and The American Prospect, is a writer living in Boston.

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