The next time you find yourself at a networking event, take a minute to look at the people around you. You’re likely to observe a lot of groups of four, which social psychologists and anthropologists have identified as the sweet spot for the number of people who can easily engage in conversation. “People naturally cluster in groups of four,” says Charlotte Blank, a neuroscientist and chief behavioral officer at Maritz who spoke to Convene about behavioral science and events for a story that appeared in our September issue. “Then when a fifth person comes along,” Blank said, “we split into groups of three and two.”
It so happens that there’s a conference taking place this week at the Made in NY Media Center in Brooklyn, where Convene rents space, so I dropped by a happy-hour reception to see for myself. I wasn’t expecting Blank to be wrong, but I still was surprised to see how how strong the tendency was. Not only were there groups of four everywhere I looked, but, compared to slightly larger groups, the people in them looked much more engaged with one another.
There’s an evolutionary basis to the way that we socialize in groups, Blank said during a talk at PCMA’s Education Conference in June. “The fifth wheel, scientifically speaking, is awkward.” There’s some evidence that the reason we cluster in fours is rooted in the small grooming circles of social animals like chimpanzees, she said. Four also might also represent the upper limit of the number of visual cues that we can cognitively manage when maintaining conversations or the number of different social perspectives we can empathize with at one time, she said.
Even Shakespeare rarely had more than four characters speaking in any one scene, points out behavioral science writer Corinne Purtill in a story she wrote about the four-person tendency for Quartz at Work.
Purtill cites research by Jaimie Krems, an assistant professor of psychology at Oklahoma State University, who theorizes that when four people gather, you are on the same footing conversationally — there an equal number of conversations that you can and cannot take part in. But when another person joins the group, there are more conversations that can exclude you than conversations that can include you.
It is possible, Krems and a co-author argue in an academic journal, that there is an evolutionary advantage to not being outnumbered in a converstional group. For our ancestors, the consequences of being excluded or overpowered could have been dire — and it still doesn’t feel comfortable to us.
The evidence for the four-person conversations is strong enough that one of Martiz’s meeting design principles is to aim to set up small-group conversations in clusters of four people, Blank said. The rule of four “is a a simple thing to keep in mind.”
It’s also something I will keep in mind when I am alone at a reception and feeling brave enough to join a small group — better to approach a group of three people than upset the fine balance of a group of four.