Best Friends Build Shared Memory Networks

“They’re always reminding me of things I’ve forgotten. They’re an extra hard drive for my limited memory capacity.”

“In science, this is known as a transactive memory system. Transactive memory systems (TMS) are repositories of knowledge that are shared between two or more people.”

“A shared memory of events, like with me and my friends, above, can be part of it, but it’s also a way of calling up facts that other people know. If you say “Oh, what’s the movie that starts with that whistling cartoon rooster?” and I say “Robin Hood,” that’s transactive memory. You have access to my knowledge, and vice versa. But, it only works if we trust each other that we both know what we’re talking about, and that we know we can call on each other for the knowledge if we need it.”

“trust was really important—the more trust you have in your friendship, the stronger your transactive memory system was.””

“And the stronger the TMS, it seems, the stronger the friendship, though it’s not clear which causes which. People who had powerful TMSs with their best friends reported higher friendship quality, even when the researchers controlled for things like trust and how long they’d known each other.”

“There are two different structures of a TMS—differentiated and integrated. In an integrated TMS, friends share similar knowledge and are able to reinforce or remind each other of what they know. In a differentiated TMS, they have knowledge of different things, and can consult each other like encyclopedias. The researchers found that in mixed-gender best friendships, TMSs were more likely to be differentiated, while in same-gender best friendships, they were more likely to be integrated. But regardless of the gender makeup, the systems were equally strong.”

“One question this research raises is whether you really need your own personal trivia team at your disposal in the age of Google. “Relying on our computers and the information stored on the Internet for memory depends on several of the same transactive memory processes that underlie social information-sharing in general,” one study from 2011 concludes. Does this mean we are outsourcing our memories more to the internet than to each other?”

“Ledbetter doesn’t think so. For one thing, the internet makes it easier to use our friends’ knowledge. “We can turn to our social network and ask for advice about repairing the car, finding a doctor, or what fun books to read during the summer,” he writes. And while you could just Google those questions too, Ledbetter writes: “We have a wealth of information at our fingertips with Google—but with our friends, we have a wealth of trust.””