Christine Gallagher Kearney is a Public Voices Fellow with The OpEd Project and President of DePaul University’s Women’s Network and the Business Manager for the Office of Public Relations and Communications.

I’ve been thinking a lot about what it means to be a woman leader in the 21^st century in the context of the 50^th anniversary of The Feminine Mystique as two women leaders left the spotlight during these past few weeks while a third prepares to instruct others to Lean In.

Within days of each other Pauline Phillips, the Dear Abby columnist, passed away in Minneapolis at age 94, Hillary Clinton prepared to step down as Secretary of State, and Sheryl Sandberg moved onto the public stage ahead of the release of her new book, Lean In: Women, Work and the Will to Lead. On the surface, these three women have little in common, one the doyenne of advice, another the doyenne of diplomacy, the third a corporate female success story. But all three negotiate their femininity as prominent women leaders to varying effect.

Phillips and Clinton held, and still hold, a unique place as leaders in American culture. They are both role models to women across the country and both women played the femininity game, leaning in and out of stereotypical feminine traits to get the job done. Phillips was trusted with intimate details of American lives. She trucked in the personal, but she also acknowledged the political. Clinton demonstrated a full spectrum of strengths during her tenure as Secretary of State, most recently at the Benghazi defense hearing, where she showcased her power, knowledge and authority in addition to her compassion and sensitivity.

As a society, we still expect women to abide by classical feminine traits and some women leaders are accepted as more feminine than others. There are those—Michele Obama, Sarah Palin—who are acceptably feminine; there are those—Margaret Thatcher, Supreme Court Justice Sonia Sotomayor—who are not. This isn’t new, and some women are making gains in the workplace, regardless.

A 2011 study completed by researchers at Stanford Graduate School of Business confirmed that women are indeed moving forward, “In the business world, women who are aggressive, assertive, and confident but who can turn these traits on and off depending on the social circumstances get more promotions than either men or other women.”

That doesn’t change the fact that women’s leadership is plagued with double standards, with the expectation that public women must be nurturing, collaborative, graceful and maternal. This expectation is ingrained in our social fabric, and both Phillips and Clinton tried, at times, to fit the mold. Phillips answered her letters sharply without losing her so-called feminine graces. For example, in 1979 she acutely suggested that “Nob Hill Residents” move after expressing discomfort with having gay neighbors. Many readers perceived her response as too liberal, but Phillips didn’t balk at the criticism. Hillary Clinton answered questions during the Benghazi defense hearing with anger and compassion, never backing down in the face of questions that had been asked a million times before. She, like Phillips, responded with wit. But humor was lost in the undercurrent to the extreme frustration Clinton felt as she slammed answers back at the panel much to the nation’s apparent surprise. Feminine women, after all, don’t show anger in public.

If we—including Sandberg—can learn anything standing in the line to leadership, we can and should look to Phillips and Clinton. We can play the femininity game, because whether we like it or not, women leaders need to come across to some extent as “still” feminine if they are to succeed. A female leader’s femininity becomes the point of departure for media analysis, character assessment and just about everything else. Instead of focusing absolutely on her strengths, regardless of gender, Barbara Walters asked Clinton a personal question—about her hair—during her recent 10 Most Fascinating People special. Case in point.

But, if we are ever to gain equity in leadership, this double standard needs to change from day one. What cannot be forgotten is that gender characteristics—masculine and feminine—are socialized traits. Girls and boys learn from a very young age what is, and what is not, an appropriate expression of their biological sex. There are consequences to stepping outside a stereotypical gender line. For example, the backlash against women’s advancement that Susan Faludi wrote about way back in 1991. More than 20 years later, there are moments of backlash still; witness the resistance to women participating in front-line combat. And there are still conservatives who respond to women’s gains by encouraging them to lean back into the figurative kitchen—permanently.

Personally, I don’t think there are too many of us from Generation Y willing to lean into the kitchen, and only the kitchen, anymore. I recognize the fantastic gains made by our foremothers with a great shout out to all the women that paved the path for women born in the 80s and beyond. But we cannot be lulled by the nostalgia of the previous generations. Mad Men is a TV show, not a model for 21^st century living. Phillips left her life as a homemaker to write, Clinton left her husband’s side to run for office, and Sandberg is encouraging us to aggressively pursue our lives in and outside the home.

Sonny Mehta, Knopf’s Chairman and Editor in Chief, believes that Sandberg’s forthcoming book “has the power to change not only our outlook, but also the world, and that it will become a touchstone publication for a generation of women.” We surely could use one, suggests Rachel Shetir, who took current women writers—Liza Mundy, Anne-Marie Slaughter, Caitlin Moran—to task in a recent article in The Chronicle of Higher Education titled “Feminism Fizzles: Where is Betty Friedan when you need her?” Shetir strongly feels that current writing on women “barely acknowledge[s] the psychological complexities, the subterranean and contradictory forces pulling at women, as well as new possibilities offered.”

The Feminine Mystique, of course, radically changed a generation of American women, including Phillips and Clinton. Sandberg has the opportunity to challenge the direction and influence the fate of the current generation of women by her example, but time will tell if playing the femininity game will be enough to change double standards around leadership placed on women at the top.

I hope Sandberg, and her book, helps challenge our outdated yet still potent double standards, because I’m next in the leadership line. By the time I’ve leaned all the way in, I can only hope playing the femininity game will be a quaint relic of times past.