Sharing a meal with your coworker might improve your performance at work. In a new study, published in the journal Human Performance, food scientists from Cornell University’s Food and Brand Lab discovered employees who eat together were more effective collaborators.

"Eating together is a more intimate act than looking over an Excel spreadsheet together," said study author Kevin Kniffin, assistant professor at Cornell University’s School of Applied Economics and Management, in a press release. "That intimacy spills back over into work. From an evolutionary anthropology perspective, eating together has a long, primal tradition as a kind of social glue. That seems to continue in today's workplaces."

For the study, Kniffin and his team interviewed firefighters throughout 50 firehouses in one city over the course of 15 months. They asked 395 supervisors from the fire departments to rate their firehouse’s performance on a scale of 0 to 10, along with how often they ate together during a typical four-day workweek. A clear link emerged. Firehouses that ate together tended to get higher performance ratings, while firehouses that didn’t eat together scored lower.

Next, researchers cross-examined the interviews from each firehouse and found daily group meals were a central activity during shifts. One firefighter, whose shift started at 6 p.m., said he would often eat two dinners — one at home and another when he arrived at work — in order to avoid disrespecting his wife and his coworkers. “To me, that’s a good example of the importance of the group,” Kniffin said. “It’s comparable to his family.”

Historically, eating together has been an important tool for building and maintaining familial relationships. Yet Americans rarely eat together anymore. The average American eats one of every five meals a week in their car, and the average family eats only one meal together during the five-day workweek.

How does this affect modern family dynamics? According to a 2014 analysis, students who don’t sit down for a routine meal with their parents are “significantly” more likely to reject authority and cut class. Previous studies have also found families who eat together tend to eat healthier meals compared to those who dine out.

Cornell’s new study reveals the same effect transcends into adulthood. When coworkers share meals together, their work performance improves. Companies that want to see an improvement in their employees’ performance may benefit from investing in upscale eateries or inviting dining areas within the office; ordering group lunches; or planning meals outside of work to encourage engagement with one another. The researchers concluded the financial investment this requires would pay off.

Source: Wansink B, Devine CM, Kniffin KM, and Sobal J. Eating Together at the Firehouse: How Workplace Commensality Relates to the Performance of Firefighters. Human Performance. 2015.