Building and maintaining strong teams is one of the most important jobs that leaders have. It can also be one of the toughest, because it’s not always clear which people will work well together and whose skills will best complement each other.

Today, we’ll get some research-backed advice on assembling great teams. It’s from this article, which is one of my favorite pieces I’ve done at Insight. I’m highlighting it today in part because this will be my last The Insightful Leader newsletter, as I’m taking a new job. (But worry not, the newsletter will be in good hands with my Insight colleagues.)

Writing this newsletter has been another one of my favorite things about working at Insight. I wish all of you well in your leadership journeys!

Now, moving on to lessons about teamwork.

Teams are more important than they used to be

Before getting into advice on how to build a great team, let’s take a look at how important teams have become.

The world of scientific research offers a telling example: a study by professors Benjamin Jones and Brian Uzzi of 19.9 million scientific papers and 2.1 million patents generated over 5 decades shows that teams are increasingly producing more work than are individuals. And those teams are getting bigger over time.

Teams also generally produce research and patents that are more frequently cited—a measure of the paper’s or patent’s impact within its field—than research by individuals. That trend has also increased over time.

In other research, Jones identifies one explanation for this trend toward teams: As technology advances, the quantity of knowledge in the world grows. With more and more to know, it becomes harder and harder for any one person to have a deep general knowledge in a field. Instead, people are joining forces to combine their specific knowledge and cover more of a field. His study on 2.9 million patents issued from 1963 to 1999 shows that team-size increases are bigger in fields with a larger “depth of knowledge,” such as biotech.

Bring in new people periodically so your teams don’t get too insular

A couple weeks ago, I wrote about another study from Uzzi that looked at collaborations within Broadway musicals. He and his colleagues wanted to understand how having repeat collaborators or those with close associations on the team affected a show’s success. They found that both critical acclaim and financial success peak when there is a medium level of these tight-knit connections: Too much, and new ideas don’t flow in. Too little, and there aren’t enough of the common bonds that allow teams to establish trust and enable members to vouch for each other’s innovative instincts.

Another study, by professor Leigh Thompson, showed similar results.

She and a colleague looked at the benefit of bringing new people into team brainstorming exercises. In several experiments with three-person teams, groups that retained their same makeup generated fewer total ideas and fewer different kinds of ideas than did teams that had one of their three members swapped out.

And it wasn’t simply that the newcomers came in with their creative guns blazing. The study showed that having a productive new person join a team increased the productivity of the old-timers, as well.

It’s not just creative teams that benefit from new members. The finding extends to the financial world, too, perhaps counterintuitively to some, as investors often seek out team stability among private-equity managers with the assumption that this cohesion boosts profits.

But a study by Kellogg Dean Francesca Cornelli and finance professor Vikrant Vig shows that this is not the case. They looked at 138 private-equity managers over 20 years and found that some degree of team turnover actually improved fund performance over both the short and long term. This is likely because turnover helps get rid of poor performers while also bringing in team members with new skills, which helps private-equity companies adapt to a changing environment.

For more on how to assemble great teams, including why you shouldn’t necessarily pack them full of superstars, you can read the full article here.