Over the last several decades, women have made tremendous gains in many professions. Women physicians, for instance, were a rarity in the 1960s. Today, about 35% of physicians are women, and the representation will only increase as women—who constitute over half of new medical students—proceed through the career pipeline. Women have made similar gains in professions such as law, veterinary science, and dentistry.

But progress has lagged in other fields. Only 18% of new computer science grads are women, and a paltry 11% of top corporate executives are women. What is holding women back? What can be done to help more women enter and achieve parity in these predominantly male fields?

There are many possible reasons for the gender gaps. They include gender biases and “bro culture” that can make male-dominated environments unwelcoming to women. Another possible explanation is that the gender gap is itself to blame—women don’t get enough support because there aren’t many other women around. Perhaps women would benefit from simply having more women among their peers.

There is some evidence supporting this. Studies show that women in undergraduate engineering programs with more female graduate mentors are more likely to continue in the major, and women who are friends with high-performing women are more likely to take advanced STEM courses.

But these studies are limited. It may be that women aren’t benefiting from the support, but that women with greater commitment to a field tend to gravitate toward similar women. This is what economists refer to as the problem of selection bias, which makes it unclear whether the peer group is what causes success. Another issue is that some surprising studies show that women’s success is actually hampered by having more female peers. This can happen when women are put in positions where they must compete with one another, because of quotas, for example, so having more women around actually makes it harder to succeed.

How do we know whether women actually help other women? Ideally, we would do something like a medical experiment where women are randomly assigned to treatment and control groups. Women in the treatment group would have women peers, and women in the control group would not. If women in the treatment group do better than women in the control group, then we have good reason to conclude that the relation is cause-and-effect.

Such opportunities for randomization are rare, but we found one. We took a cue from economist David Lyle, who recognized that student cadets at military academies are randomly assigned to peer groups called cadet companies. This can create a natural experiment for studying peer effects without concern about selection bias.

West Point

The United States Military Academy at West Point is a four-year college founded in 1802. Its mission is to train cadets to be Army officers, and the program is challenging. Standards are high and cadets’ performance is closely monitored. The student body (or Corps of Cadets) is structured as a hierarchy comparable to the Army. It is divided into four regiments, which are each divided into three battalions, which are each divided into three companies. There are 36 companies, each contain about 32 cadets per class, or about 128 members in total.

We studied the classes of 1981 to 1984, the second through fifth graduating classes that included women. In those years, cadets had few opportunities to interact with the outside world. There was no email, internet or cellphones. External communication involved snail mail or a shared pay phone. Cadets were isolated within the Academy as well. They were required to live, have meals, and participate in activities with their own companies. Opportunities to interact with cadets in outside regiments were even more limited.

Many graduates recall a brutal freshman year at West Point. Senior-ranking cadets are charged with instructing more junior cadets in military protocol and disciplining them for infractions. In the late 1970s and early 1980s, this often amounted to severe hazing.

When women first entered West Point in 1976, there was considerable controversy. Women were often singled out for particularly harsh treatment, though there was substantial variation across the student body. And with an average of 103 women spread across the academy each year, compared to 1,146 men, women had little opportunity to interact with other women. Not surprisingly, women’s attrition rates were about five percentage points higher than men’s on average—a big difference when attrition rates for men are only about 8.5 percent.

Women and Peer Groups at West Point

We collected our data from the 1976 to 1984 West Point yearbooks, which contain group photos of cadets by company and class; these were our peer groups. With this information, we were able to track each cadet’s randomly-assigned peer group by gender, and their progression from year to year.

We found that, when another woman was added to a company, it increased the likelihood a woman would progress from year to year by 2.5%. This means that, on average, an extra two women in a company on top of what it already had would completely erase the five percentage point female/male progression gap.

Another way to think about the size of the effect is to consider only first-year cadets, who have the worst attrition rates. Women in first-year groups with only one other woman only had a 55% chance of sticking around for the next year. But women in the most woman-heavy groups, with 6 to 9 other women, had an 83% chance of continuing to the next year.

One concern, however, is that while the addition of more women helps other women, it may make men less likely to progress. But, when we compared results for men with results for women, we found no effect of women peers on men, positive or negative. In other words, there was only an upside to increasing the number of women in the group.

Beyond West Point of the 1980s

Unlike other studies, the natural randomization of cadets to companies has made it possible for us to say that there is a substantial benefit to women from having women peers. But West Point of the 1980s was unusual. How would these results apply more generally?

Things have changed considerably at the institution in the past 40 years. In 1990 a woman was appointed to the prestigious position of First Captain—the lead cadet of the entire student body, and 22% of the incoming class of 2020 were women. Extreme hazing has been eliminated, and cadets have more opportunities to interact with friends and family outside and other cadets within the Academy. The need for support may have changed as the experience has eased.

There are many other reasons that these results may not carry over to a college or workplace of 2018. There is greater awareness now of the challenges that women face when they are in a small minority and greater willingness of leaders to mitigate the challenges. It would be interesting to see what a similar study would show in a corporate workplace. Until that time, the best evidence is that attending to gender when assigning women to groups can be a powerful tool for increasing the representation of women in male-dominated fields.

from HBR.org https://ift.tt/2r7kzi2