There has been a lively debate recently about why there is still a persistent lack of women in executive suites and on corporate boards in the United States. Women now make up almost half of the workforce in the US (46.7 percent in 2010) and a majority of management, professional and related positions (51.5 percent), but they are still far behind in top leadership positions. In 2011, women held only 14.1 percent of executive officer and 16.1 percent of board of director positions.

Sheryl Sandberg, COO of Facebook and an outspoken advocate for women business leaders fighting for gender equality in the workplace, said in her speech in January at the World Economic Forum that it is an “ambition gap” in the way boys and girls are being raised.

Sandberg said in her speech:

We don’t raise our daughters to be as ambitious as our sons. Last month, there were t-shirts sold at this gymboree… that said “Smart like Daddy” for the boys and “Pretty like Mommy.” Not in 1951, last month. Little girls are called bossy… I challenge you, go find someone and watch them call a little boy bossy. Won’t see it. They’re not bossy, that’s the natural order of things…

Success and likability are positively correlated for men and negatively correlated for women. As a man gets more powerful and successful, he is better liked. As a woman gets more powerful and successful, she is less liked.

Sandberg argues that on a personal level, we must stop supporting gender stereotypes by not encouraging girls to be more ambitious, assertive and competitive and not encouraging boys to contribute more to child rearing and household management. She also points to the responsibility of corporate leaders to change the culture of gender equality in the workplace, citing the necessity of equal maternity and paternity leave and using the talents of the whole workforce regardless of gender.

Joe Keefe, President and Chief Executive of Pax World Management and Pax World Funds, also points to the bottom line as another reason to increase the number of women business leaders.

“When women are at the table, the discussion is richer, the decision making process is better, management is more innovative and collaborative and the organization is stronger,” Keefe said at the Women Advisors Forum in April. “It’s not just me saying this, it’s research saying this.”

Catalyst released a study in 2011 that found that from 2004 to 2008, companies with three or more women on their boards outperformed companies with no female board members by 84 percent for return on sales, 60 percent for return on invested capital and 46 percent for return on equity.

In 2008, McKinsey released a study that found that companies with more women in senior management roles had above average earnings and financial valuations.

Do you agree with Sandberg’s “ambition gap” analysis? What do you think would help increase the numbers of women in corporate leadership roles?