Even our genetics show we have to look beyond ourselves

(CNN) This brings a whole new meaning to the phrase, Youve got a friend in me.

A new study published Monday in Proceedings of the National Academy of Science suggests friends may be more than just people you lean on when youre not strong; they might actually help you carry on genetically speaking.

Looking across the whole genome, we find that on average, we are genetically similar to our friends, said James Fowler, coauthor of the study and professor of medical genetics and political science at UC San Diego. We have more DNA in common with the people we pick as friends than we do with strangers in the same population.

Over the past decade, Fowler and coauthor Nicholas Christakis, professor of sociology, evolutionary biology and medicine at Yale, have studied the science behind social networks. Theyre seeking a biological explanation behind some long held social notions.

Weve all heard the phrase, Birds of a feather flock together, but we want to know why, Fowler said.

Using data from the Framingham Heart Study, the researchers were able to conduct what they say is the first genome-wide analysis correlating genotypes between friends.

According to the U.S. Department of Health and Human Services, the Framingham Heart Study started in 1948. It is a long-term, multigenerational study, designed to identify genetic and environmental factors influencing the development of cardiovascular and other diseases. The generational genetic data provided by the Framingham Heart Study made it an ideal starting point for Fowler and Christakis.

The study contained 1,932 subjects. One group consisted of pairs of unrelated friends, while the other group was composed of unrelated strangers. Scientists examined 1.5 million markers of gene variation to accurately measure the genetic degree to which each person was similar to his or her paired friend or stranger.

We have found that we share about 1% of our genes with our friends, said Fowler. On average our studies indicate we are as genetically similar to our friends so much as we are our with our fourth cousins or people who share great-great-great grandparents.

Of the genes most prominently expressed between pairs of unrelated friends, the researchers found that the olfactory system genes were overrepresented.

Originally posted here:
Even our genetics show we have to look beyond ourselves