Not long ago, two researchers set out to define the qualities women bring to leadership roles.

Their findings, published on Harvard Business Review, showed that women leaders outscored men in almost all areas they measured, most dramatically in two typically male-ascribed abilities - taking initiative and driving for results.

Summing up their conclusions, the two had a follow-up question: "Why are we not engaging and fully employing these exemplary women leaders?" Good question.

Why Are We Not Fully Engaging Women?

According to last year's report by Grant Thornton, a full third of businesses worldwide still have no women at a senior management level. Worse, in five years, women's numbers have risen only a paltry 5% globally. Not surprisingly, there are costs. The Grant Thornton report says companies with male-only boards are losing billions. The flipside is the gender diversity makes organizations more profitable, with a McKinsey study showing that advancing women's equality could add $12 trillion to the global economy.

So what gives? Turns out, many of the wounds are self-inflicted. Employers are pushing back on working mothers, assuming (perhaps unconsciously) that motherhood is a woman's first step out the door. But it's not. Women told our Modern Family Index as much. Turns out, they want to work. The majority of them are not only committed to careers after motherhood; they're energized by them.

But many new mothers say the workplace has been less than hospitable, exacting tolls in lost opportunities and sideways glances from managers. Many say colleagues were skipped over for promotion by merely announcing a baby was on the way. Flashy maternity leave policies may be in vogue, but nearly half of new parents say having a baby has actually stifled their professional growth. More than half say motherhood will require a job change.

The Irony of How Women Leaders are Lost

The real irony? The certainty of a woman's departure seems to be the first domino that causes it. And it will take more than a change of heart to fix. Leave policies are a start. But grooming women for leadership roles is going to require more than high-level demonstrations. It will require down-the-chain support including conversations about careers before motherhood, outreach during leave, and on-ramping when women come back.  It will also require careful thought about the kinds of benefits that can support women (dependent care, flex time, nursing support), and how they're delivered.

Such efforts promise rewards beyond just today. An additional finding by Grant Thornton is the value of mentors, considered by women to be the most important factor in their success as leaders. Women mentoring women addresses the unique priorities and complex work/life balance equations women bring to the workplace. As our own COO Mary Lou Burke Afonso wrote on Fortune, "My mentor showed me it was possible to be successful in both my professional and personal lives."

That means more women leaders will mean more women leaders.

Given the talent at stake, that's a benefit not just to women...but to everyone.