It may seem strange to ask — at a time when women account for almost 40 percent of all managerial positions, according to data from the Bureau of Labor Statistics — why so few women have made it to the very highest levels of corporations. Yet after decades of progress, the percentage of women in top management positions remains under 9 percent. And in professional positions (for example, chief financial officer) where women have done relatively well, the percentage of woman has actually declined in recent years, falling to 12.8 percent in 2011 from a high of 14.2 percent in 2004.
What factors make it more or less likely that a firm will have a woman as a top manager? While many anthropological and anecdotal studies have explored this question, few statistical studies have been undertaken. New research by Professor David Ross, working with Cristian Dezsö of the University of Maryland and Columbia Business School doctoral student Jose Uribe, is one of the first large statistical analyses of whether a given top managerial position is likely to be held by a woman. Their study, which analyzed 20 years of data from the 1,500 largest US firms, identified a single significant predictor. “If a firm already has one woman in a top management position, then the odds that another woman will also have a top position is lower,” Ross says. “It’s as if women are over-distributed among firms, or spread out more evenly than chance alone would dictate.”
Researchers have offered a wide range of theories about the underlying causes of this phenomenon, which can be broadly divided into two categories: behavior by women and behavior by men. Behavior by women includes the tendency, among some women, to not seek each other out in a corporate environment. Prior studies have shown that junior women tend not to choose female mentors and that women at the senior level tend not to take on female mentees. “Women might actually be avoiding each other, almost as if they were magnets with opposite polarities,” Ross says.
Take the perspective of the lone woman in a firm who has achieved a senior position, he explains. She occupies what might be considered an ecological niche. “If you introduce another woman who could be a competitor, that represents a threat,” Ross says. “It is as if you have two hunting animals in an area of the forest where there is really only room for one.”
A junior woman at a firm may have other reasons to avoid seeking out a female mentor. For example, research has shown that some women have internalized society’s conflicting norms about female behavior. “Some young women will encounter a female executive and will be put off that the senior woman is behaving in ways that executives tend to behave and not the way that society says women should behave” — confident and decisive, rather than inclusive and nurturing, Ross explains. “That can create personal friction.”
Behavior by men in the corporate sphere also exerts a significant influence. Organizations are under a good deal of pressure, both internally and externally, to alleviate their demographic disparities. If a firm has an all-male executive team, it may devote considerable resources to recruiting a high-profile woman from outside the firm or promoting a junior woman to the top team. However, once that first woman is in place, the urgency to find a second declines sharply.
“Even though a corporation might have only one woman in its top five positions, it sees itself as having moved one step closer to equality,” Ross says. “And frankly, that corporation is probably doing as well as or better than most other firms in terms of resolving gender disparity.”
Additionally, the tension of majority-minority relations might be at play. A majority’s reaction to a small entry by a minority into its territory — such as an all-male executive team — might be neutral or even positive. Yet once a minority reaches a certain threshold, the majority often feels threatened. Studies suggest this threshold is about 20 percent, which corresponds to one woman on a five-person team. “The attitude of the male majority might go from actively looking for a woman, and feeling good about that, to a sense that they already have one woman and don’t really need another,” Ross says.
All of these mechanisms provide theoretical reasons for why women are over-distributed in firms. Or, in other words, why a firm with one woman at the top is less likely to have another. In fact, the effect is particularly strong if a firm has a woman as its CEO. “You might expect that when a firm chooses a woman as its chief executive, it is ushering in an era of other women being promoted to the top management,” Ross says. “But that isn’t the case.”
It is both a counterintuitive and troubling finding, but one that suggests that the reasons behind the continued lack of women in top management are complex and difficult to remedy. “We have evidence that male behavior is contributing to this, because we can look at similar job categories and see how women are being selected and placed,” Ross says. “And we can see how women are influencing this by looking at women CEOs who have the power to have a tremendous effect on the gender balance of the top management team.”
David Ross is the Sanford C. Bernstein & Co. Associate Professor of Leadership and Ethics in the Management Division at Columbia Business School.
David Ross was a Columbia Business School faculty member from to 2016.