Penn studies how trendy baby names and social movements take root

Why does something become popular? Sometimes there’s a clear reason, but other times it just seems to happen. New research from the University of Pennsylvania suggests the emergence of a social norm or hugely popular baby name can happen spontaneously — but only if people are connected in the right way.

To explore the elements required for reaching a shared convention without top-down direction, Damon Centola, an associate professor at Penn’s Annenberg School for Communication, set up a game in which pairs of people met and each gave a name for an object. They were rewarded if their answers matched, and penalized if they didn’t.

When people were limited to the types of interactions they might have in a neighborhood, after four or five rounds of the game some “neighbors” had agreed on the same name. But the group at large was divided.

“This rapid success among neighbors actually impeded the success of the population as a whole,” Centola said. “That’s because these groups coalesced around different names.”

Linguistically, that division can help explain why in different parts of the U.S. the same beverage is called soda, coke, tonic, or pop.

When individuals were allowed to contact more distant neighbors, akin to a restricted telephone network, the same regionalism occurred.

Then the researchers let people interact freely, regardless of geography — much like on the Internet. At first, there was little agreement. But after 10 or 12 rounds, the entire population was beginning to reach a consensus.

“At that point, people who had never interacted before — total strangers — would meet for the first time and then spontaneously use the same word to describe an arbitrary object,” Centola said.

A similar process was likely behind the emergence of the word spam to refer to junk email.

“No one is trying to do it,” Centola explained. “It’s just a sheer function of the pattern of interaction in the network.”

The results, which were published this week in the journal PNAS, have huge implications for how culture changes in today’s online world. Whereas in the past the civil rights and environmental movements relied on organizers to pull people together, events like the Arab Spring emerged without formal leaders.

“Simply by having people connected in this way,” Centola said, “it makes social change like that much more likely.”

Large-scale shifts in belief, made possible by online communities, could be positive or negative for society. Centola is working on better understanding those dynamics and whether any accuracy is sacrificed as the masses rapidly pick up a message.