Can't help being the life of the party? Maybe you were just born that way, say researchers from Harvard University and the University of California, San Diego, who report that our place in a social network is influenced in part by our genes. Theirs is the first study to examine the inherited characteristics of social networks and to establish a genetic role in the formation and configuration of these networks. "We were able to show that our particular location in vast social networks has a genetic basis," says Harvard's Nicholas Christakis. "In fact, the beautiful and complicated pattern of human connection depends on our genes to a significant measure." While it might be expected that genes affect personality, these findings go further and illustrate a genetic influence on the structure and formation of an individual's social group.
The researchers found that popularity, or the number of times an individual was named as a friend and the likelihood that those friends know one another were both strongly heritable. Additionally, location within the network, or the tendency to be at the center or on the edges of the group, was also genetically linked. However, the researchers were surprised to learn that the number of people named as a friend by an individual did not appear to be inherited.
The researchers believe that there may be an evolutionary explanation for this genetic influence and the tendency for some people to be at the center while others are at the edges of the group. If a deadly germ is spreading through a community, individuals at the edges are least likely to be exposed. However, to gain access to important information about a food source, being in the center of the group has a distinct benefit.
"One of the things that the study tells us is that social networks are likely to be a fundamental part of our genetic heritage," said co-researcher James Fowler. "It may be that natural selection is acting on not just things like whether or not we can resist the common cold, but also who it is that we are going to come into contact with."
Because both health behaviors and germs spread through social networks, understanding how contagions flow through social networks has the potential to improve strategies for addressing public health concerns such as obesity or the flu. "I think that going forward, we are going to find that social networks are a critical conduit between our genes and important health outcomes," says Fowler.
Source: University of California, San Diego
