Even just casual, friendly acquaintances fuel productivity, collaboration, and creativity. Strong social ties between employees also make it more likely that they’ll stick around. Retention is no small thing in the age of the Great Resignation.

Think of how much smoother a project runs when everyone trusts, respects, and actually likes each other: You joke around, you forgive errors, you make jokes that lead to breakthroughs.

Especially important, and harder to create remotely, are the connections you make at work with those outside your own team: Ties forged in the minutes before the meeting gets started or in the office kitchen or hallway or, yes, in the bathroom (more on that farther down).

“It’s the opposite of groupthink when you have ideas flowing across boundaries,” said Nancy Baym, senior principal research manager at Microsoft. “These weaker ties are really important for bringing ideas and freshness into organizations.”

They help workers build “social capital,” Baym explains in a piece she co-wrote for Harvard Business Review. They are “the soil in which ideas grow.”

But looser connections took a big hit in the pandemic when everyone went remote, according to a study from a group of researchers at Microsoft, published in September in the journal Nature and Human Behavior. While Baym was not directly involved in the Nature study specifically, she conducts similar work.

The researchers examined a trove of internal data from more than 61,000 employees in the U.S.—their emails, calendars, chats, calls and hours logged, covering the first six months of 2020. All the information was anonymized.

They found that employees became much more siloed during the pandemic. While workers were interacting with their own small teams more, there was far less cross-team collaboration. One striking example: as part of their work, the researchers looked at data from Microsoft Teams chats and found the number of chats that were between small groups or one-on-one conversations increased 87%, while larger group conversations decreased by 5%.

The results aren’t a death sentence for remote work, Baym said. It’s possible, things have improved since the study ended. More folks are working hybrid or are back in-office now. And it’s worth noting that for some groups, connections seem to increase.

“This study could’ve found when people went remote they quit communicating with everyone. That’s not what happened,” she said. “But it is worrisome that people are not forming those kinds of broader connections within their organizations.”

Weak ties of all sorts have been rattled by the pandemic. Because more people are staying home, wearing masks, and keeping their distance, there’s just less opportunity for the kinds of spontaneous interactions with strangers and acquaintances that we didn’t know we needed. I miss those easy conversations—with the guy who sold me my coffee, the fellow commuter on the train platform, or the woman I always seemed to run into in the bathroom.

I’m serious.

I met one of my greatest work friends in the office restroom. This was more than a decade ago, and it feels like it could never happen now. I was about five months pregnant at the time, and so was she. I overheard her talking about it at the bathroom sink. I introduced myself.

Over the next months, we talked through our pregnancies, maternity leaves and returns to the office. Our employer was slowly coming around to the idea of working mothers back then. There was no real maternity leave. Information was hard to figure out. Having a work friend to navigate a stressful time was invaluable for us—and for the company, which retained two employees through a turbulent time.

Bottom line: people like to come to work and talk to their friends. Those bonds serve the very useful purpose of spreading information—here’s the form you need to fill out!—throughout the organization.

“We know from pre-pandemic research that people who feel socially connected to folks at work are less likely to leave,” said Baym. “Connecting to other people can provide one reason to stay.”

Baym said companies are going to have to experiment a bit to figure out how to fix these issues. For hybrid workplaces, where people still live relatively close to the home office, solutions might include some on-site brainstorming meetings or establishing onboarding as an in-person process. For fully remote workplaces, maybe a quarterly in-person meetup could help.

A lot of employers are trying out different kinds of remote happy hours. I’ve found “fireside chats” on Zoom, where a member of one team does some q&a with another team can be good; or virtual coffees.

But cross-team contact can be a more practical project. Companies might want to intentionally set up some group projects, or training, that cut across different teams.

For example, to conduct their study, part of a bigger project examining the effects of the pandemic on work, Baym, who is in Cambridge, Mass., collaborated with colleagues in Seattle. “It’s been so meaningful to have people to connect with across the company at a difficult time,” she said.

emily.peck@consultant.fortune.com

Emily Peck

One story, one quote, one number

• The End of Trust: This piece in The Atlantic dives deeper on the consequences of the collapse in weak ties brought on by the new ways we are working.

• “Rest is not idleness, and to lie sometimes on the grass under the trees on a summers day, listening to the murmur of water, or watching the clouds float across the blue sky, is by no means a waste of time.” — 19th century author John Lubbock, quoted in a piece in Psyche that argues for the productivity benefits of doing...nothing.

• 60% — The share of large employers using software to track their workers, according to the 2021 Gartner COVID-19 Benchmarking Against Your Peers survey looking at 101 companies. This number doubled in the pandemic.