March 22, 2013
Humans Use Memory Tricks To Track Complex Social Networks
redOrbit Staff & Wire Reports - Your Universe Online
Humans keep track of our vast social networks by using special memory tricks that cheat complexity, rather than using routine memorization, according to a new Cornell University study.These memorization shortcuts effectively simplify rules, the way in which a person might remember a number sequence that always increases by two, according to lead author Matthew Brashears, assistant professor of sociology.
People recall social ties that both involve at least three people who know each other and kinship labels such as "aunt" twice as well as they remember ties that do not, even though triad kinship networks are far more complex, Brashears said.
"Humans are able to manage big, sprawling, complicated social networks essentially because we don't remember big, sprawling, complicated social networks. We remember simplified, regular structures that bear a reasonable similarity to what those networks look like.”
In cases where the relationships do not fit the pattern, we remember the pattern and the few exceptions, instead of remembering all the ties simultaneously, he explained.
The researchers had roughly 300 study participants read paragraphs describing a group of people and how they were related to one another. Some paragraphs included kinship labels while others did not.
Some of the paragraphs included closed triads, in which three people knew each other, while other paragraphs did not. The participants were then asked to recall as many of the ties as possible.
When the paragraphs contained both kinship labels and closed triads, the participants' recall improved by 50 percent compared with participants whose paragraphs included neither, even though the kinship and triad paragraphs contained nearly twice as many relationships.
"That's a pretty substantial improvement," Brashears said.
Moreover, participants did worse when trying to recall paragraphs that had kin relationships but no triads.
"It's like trying to remember a random number sequence by using the 'increase by two' rule," he said.
The study helps explain how humans actively manage so many more social ties than compared with other primates — a key question in the field of sociology.
The answer is that we evolved the capacity to spot and use social patterns.
"Our ability to remember and manage socials ties — and build bigger groups of people — had to do with coming up with new and interesting ways of compressing that information. It's about how we structure our groups and how that allows us to remember them, as opposed to just sheer cognitive horsepower," Brashears said.
The research may help also explain some peculiarities of human networks, such as transitivity. For example, if George is my friend and Susan is my friend, then Susan and George are likely to be friends.
Brashears suspects that some social networks are easier to remember than others, and individuals who build groups that conform to those rules were more evolutionarily successful.
"Some of the reasons why human networks look the way they do is because they have to, in order for us to process them, to manage it cognitively," he said.
Medical researchers may benefit from the study as they seek to understand why some people don't grasp social intricacies as well as others.
"We may have a better ability to understand social anxiety and autism spectrum if we understand how we're compressing and reconstructing social information using these mechanisms," Brashears said.
The study was published Thursday in the journal Nature.