When Matt Krentz became an entry-level consultant at BCG (Boston Consulting Group), he had a number of women colleagues. As he rose in the ranks, however, he found that at each level, there were fewer and fewer women.

By the time he was promoted to lead the Chicago office, he was dismayed to find that there wasn't a single female partner there.

So he started to take stock. For real. He took a hard look at the way men and women interacted at the firm, their habits, and their environments. And he began breaking down the company culture--specifically the aspects of it that were alienating women. One of his most important observations: 

"We are a very critical culture." 

Elaborating on the nature of the culture, Krentz told Lipman that at BCG, "we often tell people what they need to get better at."

While this kind of feedback can be effective for men, it is well-established that for women, it can be devastating. Research repeatedly shows that women react far more strongly to negative feedback than do men. When given both positive and negative feedback (such as in a performance review), men tend to focus on the positive, while women put a heavier emphasis on the negative. Over time, that emphasis can be crushing.

In other words, what was happening at BCG is likely what happens at most large consulting firms (not to mention the rest of corporate America). In Lipman's words, "women took the critical feedback to heart so strongly that it undermined their confidence."

This has major consequences in the workplace. At BCG at the time, it meant women were quitting at higher rates--and were being fired at a disproportionately greater rate. Teams were losing high-performing women at every level. This is important because it impacts not only the culture, but also the bottom line. Having more women at the top is repeatedly linked to a company's having higher profit margins. 

Rather than simply wringing his hands, though, Krentz was determined to do something about the situation. Along with several like-minded colleagues, he looked at his own contribution to the issue ... and considered how to adjust.

One of the conclusions he and other executives came to was that rather than asking women to change, to harden up, to "learn to take criticism," they needed to shift the culture. 

"[W]e need to change the environment in which we work," Krentz told Lipman, "how we give feedback, and more proactively engage on how we are mentoring, sponsoring, guiding [women]."

So they did.

One thing Krentz spearheaded was pairing women with successful partners in a program that emphasized more than just mentorship.

"A mentor isn't good enough," Krentz continued. "You need someone who will stick their neck out and say, 'Yes, I will vouch for this person.'"

You need a champion.

Women with champions, it turned out, wanted to stay at the firm a lot more than before. As the culture shifted, results followed: By the time Krentz moved on from the Chicago office, almost 20 percent of partners in the Chicago office were women.

Read that again: Shifting the culture in this way resulted in the firm going from 0 to 20 percent in women in executive leadership positions. 

The firm also changed how it did performance evaluations. BCG began focusing on strengths, not just weaknesses, and called out the areas of strength as places to develop (rather than ignore, since they seem fine). 

Managers were trained to scan their own feedback to ensure they didn't "fall back on male-dominated tropes," Krentz said. Tropes like "You need to be more confrontational in meetings, you need to speak out more." According to Krentz, "Just telling someone to do that and then watching to see if they can do it is poor development, but we default to that because men will respond."

Again, the result was dramatic. Within just four years, the number of women consultants grew by 70 percent. 

Seventy percent.

Most men I know want to see gender equality. They want to see more women business owners, more women executives, more women political leaders, more women in power everywhere.

But they feel helpless in terms of how to do so. (In case you're a man who does want to help, I can't recommend Lipman's book enough. It's both practical and illuminating.)

It's also important to call out the fact that Matt Krentz wasn't alone in his efforts. He was an ally to his women colleagues, but he also had allies--both male and female. For example, when he approached other like-minded male executives in his plan, they jumped on board.

When he and others trained male managers about the critical feedback, its effects, and how to shift it to make the environment a more welcoming place for women, many of those male managers responded.

They all worked together--and their focus was not on how women could change, but how they themselves could change their own culture. Their own words. Their own team meetings. Their own emails. 

It got personal.

They were willing to learn how to adjust their own ways of speaking and acting with their women colleagues, and that consciousness made a difference.

"[O]ur male leaders need to be engaged on this," Krentz said simply. If we want to move the needle, "we have to behave differently."

This conversation can be contentious and difficult and can prompt feelings of shame or fear. But it's important, and the victories we can win make it well worth it.

It doesn't have to take long, either. When both sides reach out across the gender divide toward one another, we make strides far bigger than we could ever make alone.