Social Networking May Be An Inherited Skill
January 9, 2013

Social Networking May Be An Inherited Skill Say Duke Researchers

Brett Smith for - Your Universe Online

Networking might be the key to moving along in your career path, but it´s also a great way to meet that special someone — and it´s a skill that just might be inherited.

That´s the conclusion of researchers who have just completed a new study titled “Genetic Origins of Social Networks in Rhesus macaques” which was recently published in the journal Nature Scientific Reports.

"If you are a more social monkey, then you're going to have greater reproductive success, meaning your babies are more likely to survive their first year," said post-doctoral research fellow Lauren Brent, who led the study. "Natural selection appears to be favoring pro-social behavior."

"This is really a landmark paper," said James Fowler, a professor of medical genetics and political science at the University of California-San Diego who studies human social networks but was not part of the study. "They're showing that the positive behaviors which build social networks might be heritable, and that's consistent with what we've been seeing in human studies."

In the study, researchers spent two years observing the social interactions of a group of free-ranging monkeys as well as analyzing their family trees. These macaques are the descendents of a group of monkeys released in 1938 from India on the undeveloped 38-acre Cayo Santiago Island off the eastern coast of Puerto Rico.

After learning to identify each of the almost 90 monkeys on sight, field researchers recorded social interactions between individuals in 10-minute periods, recording some four to five hours of behavioral data per primate.

Based on the observational data, the team constructed a network of interactions to analyze pro-social and anti-social behavior. They also used a metric that they called "betweenness" — or the shortest paths between individuals — and "eigenvector," a friends-of-friends measure that showed degrees of separation among a group of friends.

"The really 'popular' monkeys would have a high eigenvector, or a really big friends-of-friends network," Brent explained.

The researchers also found less-popular outliers who had fewer social interactions and a lower eigenvector. "They're sort of the dorks," she added.

The data and constructed models revealed that "a lot of these network measures popped out as having significant heritability," or traits that run in families, Brent said.

An analysis of aggressive interactions between monkeys didn't reveal much in the way of heritability, but it did affect reproductive success, with monkeys who were either most aggressive or most passive faring better than those with a temperament somewhere in the middle.

The team also performed a genetic analysis that focused on two genes in the serotonin system of the monkeys. Serotonin, a naturally occurring biochemical in humans and primates that carries signals between nerve cells, is part of the system acted on by antidepressant drugs, so it has been widely studied in humans.

"The way that genes can affect behavior is by their influence on neural circuits," said Michael Platt, director of the Duke Institute for a Brain Sciences and the Center for Cognitive Neuroscience. "We know that neural circuits for a variety of things like social behavior, food and mood are under the influence of serotonin signaling, in both humans and monkeys."

The study concluded that social success comes from good social skills and a favorable temperament, both of which appear to have a genetic basis.

"We can see that some of these behaviors have a genetic basis, from what we know of the pedigrees and the network map," Brent said. "But we've only scratched the surface of figuring out which specific genes are associated with each behavior."