By Susan Milius, Science News
Not to reopen any emotional scars from Thanksgiving dinner, but an unusual study of an animal social network suggests that ending up as the butt of unfriendly interactions could be in part inherited.
The study, in yellow-bellied marmots, gives the first look beyond people at what facets of social relationships might have genetic components, says coauthor Daniel Blumstein of UCLA.
It’s receiving incoming social attention, particularly in grouchy interactions, that showed a small but intriguing genetic influence, Blumstein says. Aspects of initiating interactions in a network, whether to dish out snubs or snuggles, showed no evidence of heritability, according to the paper posted online November 29 in the Proceedings of the National Academy of Sciences.
“I am completely blown away by this paper,” says James Fowler, professor of medical genetics and political science at the University of California, San Diego. In human networks, he and his colleagues have found the marmotlike pattern of heritability in aspects of received social ties but not in initiated ones. Fowler had suspected that the asymmetry in people came from a quirk of limiting the number of friends in the study. Marmots didn’t have that limitation though, he says, “so the idea that there may be something systematic here between species is extremely interesting.”
Marmots don’t have Facebook yet, but animals living among clusters of burrows in Colorado do interact enough for observers to plot networks with each marmot as a node. An exchange might be friendly, such as a marmot grooming a neighbor or settling down tranquilly nearby. Or a social interaction might go sour, with one marmot nipping or chasing another. “Marmots are grumpy with each other,” Blumstein says, but rarely cause serious injuries.
As in other network studies, marmot researchers examined such features as the number of ties individuals have as well as broader aspects of social life such as the likelihood that two “friends” of an individual are connected to each other.
Finding a genetic influence on being the recipient in negative interactions may reflect an overlooked aspect of a valuable social trait, Blumstein says. Marmots that are in the middle of things socially appear to thrive, but plentiful social interactions mean more bumps and grumps. “If you want to be in a group, you have to take the nasty stuff,” Blumstein says. Being able to tolerate that abuse instead of shying away from interactions that might end unfortunately could indeed be a trait favored by evolutionary forces.
Yet most studies of social interactions focus on the beneficial relationships. Now coauthor Amanda Lea, also of UCLA, suggests, “We need to rethink our traditional view of affliative interactions as good and agonistic ones as bad.”