'Destined' to be friends

Think of your friends, especially the two to 10 people that come to your mind. How would you feel knowing that there might be a genetic relationship between you and them? But before you all say “uh-oh” read on.

We have always considered friends as people whom we choose, in contrast to our family to whom we are born, for good or bad, without consultation. But recently, researchers have decided to study data from two big independent studies which take into account the genetic information of the respondents as well as the friends they named. They found out that there are things about our genes and the genes of that of our friends that are more than just a coincidence. The study was published in the early edition of the Proceedings of the National Academy of the US. The work is entitled “Correlated genotypes in friendship networks” done by James H. Fowler, Jaime E. Settle, and Nicholas A. Christakis.

The study opened with a statement that you would not find in a greeting card about friendships: “Humans are unusual as a species in that virtually all individuals form stable, nonreproductive unions to one or more friends.” But to science, that is coming from the perspective that considers most other species. Face it, we are pretty unusual in that we seek friends with a passion. If “friends” did not mean much to us, psychologists would be hard-pressed to explain Facebook. And boy, are we loyal, and sometimes more, to our friends than to our family.

The study looked at six genes to see what variations of each occur in the subjects and their friends. Humans have 25,000 genes and it will take more studies to cover all these genes but for this study, the scientists picked six genes for their known associations with social behavior. These genes are among those that affect the presence of neurotransmitters like serotonin, which affects mood and dopamine which influences our feelings of pleasure and reward.

Of the six genes tested, there were two genes that checked out in a way that alerted the scientists. The first, the DRD2 gene, when present in the subject, turned out to be present in their friends, too. This gene in different variations has been associated with alcoholism in other studies. It turned out that people who have variants of this gene chose friends who also had the same gene variants. So if you are an alcoholic or have the gene that predisposes you to become one, this may spell doom. This finding is important because it would mean that when studying alcoholism, it was not only important to study the genes of the alcoholic but also his or her friends who might be reinforcing each other’s condition because of the presence of the same genes.

A second gene, the CYP2A6 gene, presented itself to the researchers the other way. This gene is associated with several traits such as the ability to metabolize compounds like nicotine as well as a gene that affects our mental ability to be open to new things. The study found that people with variants of CYP2A6 gene were more likely to be friends with people with different CYP2A6 gene variants. It means that people who have this gene, tend to choose friends who do not have the variant they possess. This would echo what we have observed about attracting opposites. Science just proved it, at least for this gene.

This finding tells us that when we choose our friends, our genes, at the very least these two genes, are also at work. Whereas science has always known that you share genes with your family members, this time, it is finding out that genes are also at work, in a different way, when we choose our friends. It seems that our friendships are not free from the biology that ties us to our families.  

There is a funny saying that goes something like “Friends are God’s apology for family.” It seems that with this finding, we have to look somewhere else for an apology.

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