Old Study Suggesting Genetic Link With Friends Goes Viral

An earlier report (2014) published in the Proceedings of the National Academy of Science has suggested that humans might be genetically linked to their friends. James Fowler, co-author of the study, had said in an interview, “Looking across the whole genome, we find that on average, we are genetically similar to our friends.” James is also a Professor of medical genetics and political science at the University of California San Diego. The co-author added, “We have more DNA in common with the people we pick as friends, than we do with strangers in the same population.” Nicholas Christakis, professor of sociology, evolutionary biology and medicine at Yale, is another author behind this study.

The study, which contained 1,932 subjects, examined two groups. One group consisted of pairs of unrelated friends, while the other group was composed of unrelated strangers. As per the study, the 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. According to James, they had found that humans share about 1 percent of our genes with their friends. On average, the professor said that their studies indicate we are as genetically similar to our friends as we are to our fourth cousins or people who share great-great-great grandparents.

The researchers studied the genes most prominently expressed between pairs of unrelated friends. They concluded that the olfactory system (connected with the sense of smell) genes were overrepresented. James said that the friends tend to smell things in the same manner. In prehistoric days, for example, he described that people who liked the smell of blood might hunt together. On the other hand, gatherers might prefer the smell of wildflowers. Nowadays, James had said, this translates into people who like the smell of coffee congregating at shops.

According to the researchers, their DNA could be a driving force behind the activities we are drawn to and the social activities we engage in. As such, we are more inclined to interact and foster friendships with genetically similar people.