What happens when workplace colleagues compete outside of work? A study from Wharton explores this question, using sports data to show how outside rivalries affect teamwork—and offering managers ways to keep teams united. The findings apply far beyond sports.

The study examines how people’s connections to organizations beyond their workplace can put them in competition. For example, two executives might serve on rival corporate boards, or employees may back opposing political parties, creating tension.

Friendly rivals

To study this, researchers looked at professional soccer players. These athletes play for the same club—like Real Madrid, Manchester United, or Bayern Munich—but often compete against each other in international tournaments like the FIFA World Cup.

The researchers tracked how often club teammates passed the ball to each other before and after playing as rivals for their national teams. The results were striking: after facing off in the World Cup, teammates passed the ball to each other 11% less often in the next club season. This shows how external rivalries can reduce cooperation, even after players return to their shared team.

“Their tendency to collaborate drops significantly after facing each other at the World Cup,” the researchers explain.

The effect was stronger for players with deeper ties to their national team. Those without dual citizenship, for instance, were more affected than those with weaker national identities.

A sense of unity

“This suggests the importance of strengthening the sense of unity within an organization,” the authors note. “When employees see themselves as part of a team, they are less likely to let outside rivalries interfere.”

The researchers see parallels in business. Executives who serve on rival corporate boards may carry that tension into their main workplace, leading to reduced collaboration or even distrust. At Home Depot, for example, former executives Carol Tomé and Marvin Ellison held board positions at UPS and FedEx—two logistics firms in direct competition. Such roles can create conflicts that weaken teamwork.

How can companies prevent external rivalries from harming internal collaboration? The researchers offer practical steps for managers:

• Foster a culture of collaboration. When employees see each other as teammates rather than competitors, outside conflicts are less likely to spill over.
• Set clear boundaries. Companies can create policies on external engagements to minimize conflicts of interest. Some, like Basecamp, have even banned political discussions at work to reduce workplace tension.

Ultimately, external connections can be valuable, but organizations must be mindful of their effects. A strong team identity can help prevent outside competition from disrupting workplace cohesion.