Larger scientific groups have become much more common over the past 50 years. And these larger groups outperform smaller ones, producing research that is more cited by other scholars. That was the key finding of a 2007 paper from the Kellogg School’s Brian Uzziprofessor of management and organizations, and Benjamin Jonesstrategy teacher.
Now researchers are not only looking at the size of a group but also its composition. In new research, Uzzi and Jones found that the gender mix in teams matters. Mixed-gender teams produce more novel and effective scientific research than all-male or all-female teams, according to the paper, which was authored by Yang Yang of the University of Notre Dame, Yuan Tian of New York University and Teresa Woodruff of Michigan State University.
In fact, “the more gender-balanced the team is, the better the team does,” Uzzi says. Simply put, “men and women are part of the recipe for success in science. We are better together.”
Mixed Gender Teams perform better
Uzzi, Jones and their colleagues analyzed 6.6 million biomedical scientific papers published from 2000 to 2019, using an algorithm to infer the gender of authors from their names. (This method, while imperfect and unable to capture the complexities in gender expression or identity, was highly effective and produced evidence consistent with official data on the gender composition of medical school faculty.)
The researchers then calculated the impact and novelty of each paper at the time of publication. Impact was measured by the number of citations the paper received. a paper was considered highly cited if it was in the top five percent of citations in a given year.
The researchers measured innovation by examining the citations each paper contained. “If I see in the reference section of a paper that they cite Leonardo da Vinci and Einstein—and Einstein and Leonardo da Vinci have been cited together in many other papers—we would consider it a conventional mix,” Uzzi explains. “But if Einstein is paired with Maya Angelou for the first time in the citations of a scientific paper, that would be a new combination,” and one that suggests new knowledge is being advanced. The researchers used this citation information to calculate a novelty “score” for each paper in the dataset.
Mixed-gender teams significantly outperformed same-sex teams in both innovation and impact, the researchers found.
A mixed-sex group of six or more researchers was 9.1 percent more likely to produce a new paper and 14.6 percent more likely to produce a highly cited paper than a same-sex group of the same size. Furthermore, the benefits of innovation and impact were stronger when the teams were gender balanced—that is, a team of three men and three women was more likely to produce highly cited new research compared to a team of four men and two women.
They then examined whether these findings would hold even when accounting for a variety of non-gender factors that could influence the outcome of a team’s scientific research.
For example, the researchers considered the possibility that groups with men and women had more areas of expertise, which could explain why those groups’ research appeared more original. There was some truth to that story, they found: mixed-gender teams “tend to have a greater diversity of expertise,” says Uzzi. “But you still have a distinct innovation just from having a mixed-gender team.”
The benefits of mixed-gender teams also remained when considering the size of the authors’ professional networks and the geographic diversity of the team, as well as the research areas represented, such as cardiology or neurology.
In addition, the researchers conducted a preliminary survey on the gender of the group in other areas of science. They looked at more than 20 million more papers in 18 scientific disciplines other than medicine and found that the same pattern extended to papers published in all scientific fields—not just medicine—over the past 20 years.
Gender diversity is better for creativity
While the research didn’t directly address the question of why mixed-sex teams outperform same-sex teams, Uzzi has a general hypothesis. “We think gender affects the process by which scientists generate ideas and then choose the best ideas to pursue,” she says. In other words, perhaps the exchange of ideas is more lively, creative and constructive in a racially diverse group.
Whatever the exact reason for the benefit, Uzzi says he tries to make the most of it in his own research. In his lab, for example, he makes sure the research teams are gender diverse. “I feel like it leads to better results,” he says, “and I think it helps make the process more productive and fun.”
Mixed-gender groups are more common — but still underrepresented
However, not everyone does this. The researchers found that while the percentage of mixed-gender teams is increasing — between 2000 and 2019, the percentage of four-person teams that were mixed-gender rose from 60 to 70 percent — there are still fewer than would be expected if the teams were assembled without to take gender into account.
To quantify this, the researchers developed a theoretical model that randomly generated groups while holding constant factors such as the medical subfield represented, the geographic diversity of the group, and the number of author citations. This model revealed that mixed-gender groups are underrepresented by up to 17 percent.
“The benefits of gender diversity are kind of hidden,” says Uzzi, “and because they’re hidden, they’ve been underutilized. People are not taking advantage of this potential approach to do better science.”
