Is it true, as Facebook COO Sheryl Sandberg recently told graduates of Barnard College, that college-educated men are more ambitious than their female counterparts? Does that ambition gap account for the disproportionately small number of women who hold positions of power in the government and private businesses? Giving the keynote commencement address at Barnard - an all-women's college located in New York City - Sandberg said that gals need to " think big "when it comes to their careers and not shy away from high-power positions.

Men, she told the audience, "are more ambitious the day they graduate from college; they remain more ambitious every step along their career path. We will never close the achievement gap until we close the ambition gap. But if all young women start to lean in, we can close the ambition gap right here, right now, if every single one of you leans in. Leadership belongs to those who take it." An inspiring message, to be sure, but are we certain the problem is that women just aren't dreaming big enough? Women in the working world are forced to make extremely difficult decisions, especially if they decide to have a family.

Employers skip over women for promotions, assuming that they'll soon drop out of the workforce because of pregnancy or childrearing. Although motherhood is a goal for many young women, it is often not compatible with high-caliber professional work - it really is tough for ladies to have it all. Can we be both the CEO and the perfect housewife? We will be frowned upon if we appear to be choosing our jobs over our kids, but we'll never reach those high-powered positions if we aren't totally committed to the job. Men rarely have to face this kind of scrutiny, even if they have a family - maybe that's why more of them are CEOs.