It happens at the end of most virtual meetings: One person waves goodbye, and colleagues follow suit. Why we still do this, nearly four years after remote work went mainstream, is one of the mysteries of the modern workplace.

To some experts in human behaviour and communication, the so-called “Zoom wave” emerged due to our need to recreate the social connections that the pandemic ruptured. For others, it’s a simple way to signal the meeting is over before digitally departing. Some wave just to be polite, others enjoy it. Whatever the reason, it’s as much a remote-work ritual as wearing sweatpants with a business-friendly top (known as the “Zoom mullet”).

“I am a big fan of the wave,” said Erica Keswin, a workplace strategist and author. “People like to know when something begins and ends. Those beginnings and ending are what I call ‘prime rituals real estate,’ and rituals give us a sense of belonging and connection.”

She’s not alone. A survey this month by professional network Fishbowl found that 55% of workers wave. That’s down from the 57% who said they did so last year in a survey by Zoom Video Communications Inc., and the three out of four who said so in 2021. The gradual decline, as the pandemic receded and millions of workers returned to offices, doesn’t surprise Susan Wagner Cook, associate professor at the University of Iowa’s Department of Psychological and Brain Sciences and director of the school’s Communication, Cognition and Learning Lab.

“As people’s need for connection declines, they are less likely to wave,” said Cook, who has spent years studying why and how humans use hand gestures—from the friendly wave to the unfriendly middle finger—to communicate and connect.

Cook and other experts don’t foresee the wave going away completely, though. One big reason is something called “motor resonance”—when a person waves, it’s almost automatic to wave back. Multiple social-psychology studies show that we’re more likely to be empathetic and cooperative toward people that we’ve synchronised movements with, and empathy and teamwork were things many organisations struggled to instill during the stressful days of covid-19 lockdowns.

“In a video call, last impressions are as important as first impressions, and waving sends a signal that others can feel safe in our presence,” said Darren Murph, a hybrid-work advisor who now handles strategic communications at automaker Ford Motor Co.

The dynamics of virtual versus in-person meetings also play a role in the wave, according to Jesper Aagaard, an associate professor of psychology and behavioural sciences at Denmark’s Aarhus University. After a face-to-face meeting, there’s a so-called interstitial period where people linger and chat as they walk out together. But video calls end abruptly, so we need to say our farewells all at once. “This, in turn, lends an exaggerated and cartoonish quality to the Zoom wave,” Aagaard said.

It’s the awkwardness of the wave that puts some people off, but by not waving, workers risk being seen as rude. “It bothers me when I wave, and people don’t wave back,” says Molly Beck, founder and CEO of enterprise communications software maker WorkPerfectly. “I would compare it to when you hold the door for someone and they don’t say thank you.”

In other words, Cook said, the cultural cost of being perceived as impolite “outweighs this momentary feeling of, ‘Am I a weirdo?’”

Some workers are conditional wavers. Cali Williams Yost, a flexible-work strategist, says she waves when Zooming with new contacts, almost as a “nice to meet you” gesture. But if it’s the same group every week, “rarely does anyone wave, including me.” For others, it’s the type of wave that matters. “I recommend the fast wave, as if another car was letting you go first at a busy intersection, not the type of slow wave if you were on a parade float,” Beck said. And while she’s waving with one hand, Beck leaves the call with the other.

“It’s a little embarrassing, aggressively corny, and serves no purpose other than sincerely acknowledging the other people in the call,” journalist Justin Pot wrote in a 2021 blog post about Zoom waves on the website of Zapier, a fully-remote business software maker whose staff often deploy the Zoom wave. “But that’s why it’s great. No one should feel bad for doing it.”

Not everyone agrees, but workers likely won’t be saying farewell to the Zoom wave anytime soon.

“Humans adapt to media, and some of the habits which have evolved to manage the strangeness of videoconferencing have endured,” said Jeremy Bailenson, founding director of Stanford University’s Virtual Human Interaction Lab, who has studied another remote-work phenomenon—Zoom fatigue, the exhaustion suffered from videoconferencing all day. “The long wave may be with us for some time.”