Who would have guessed that the song “When You’re Smiling” is evidence-based? According to management professor Sigal Barsade, not only do facial expressions transfer from person to person; so do moods and emotions. “If I smile, you’ll smile, but it’s not just mimicry,” Barsade said during her whiteboard lecture on emotional contagion at work, adapted from her Emotions in Organizations course for Wharton Executive Education. “We actually feel the emotion.” What’s more, people don’t realize that they’re experiencing the mood because it’s been passed along; instead, Barsade said, “They own the emotion as their own.”

Most of us have observed the effect in our day-to-day lives: When another person smiles, we tend to smile, too. Emotional contagion has been recorded in humans as young as six weeks old. In the workplace, astute customer-service workers know that when they smile, customers respond in kind—and leave bigger tips.

Barsade recently heard from a professional working with youth correctional facilities who used emotional contagion research to help create a new program that treats and deescalates aggression. Both the young people and the staff were successfully trained in understanding how emotions are passed along and how to avoid spreading further aggression.

Emotional contagion can also ignite anxiety and even have an adverse impact on group effectiveness. To test the theory, Barsade planted an accomplice in a group and watched the dynamics. “When he was positive,” said Barsade, “the group he was in was more cooperative and felt more successful.” But when he was negative, his group was more conflictual. Barsade noted that the mood of someone at the center of attention—like a supervisor—can have a great impact. In other words, managers can use this knowledge to improve team dynamics and increase productivity.

“The biggest feedback I get when I speak to employees about emotional contagion is that this explains so much about what’s going on at work between people and among groups,” said Barsade. “People have used emotional contagion to be more thoughtful about how they’re interacting with others, how they’re regulating their own emotions. We take the emotional part of the interactions more seriously when we realize that it influences outcomes.”


Published as “At the Whiteboard With Sigal Barsade” in the Fall/Winter 2019 issue of  Wharton Magazine.