Just how do we choose our friends?: image via media.desicolours.com Though most of us don't like to admit it, we unconsciously make decisions about our likes and dislikes on an almost instantaneous basis. Snap judgments are made about people as well as ideas and objects we come in contact with, even if we ultimately chose to examine them further.
But what causes these snap judgments? Could our genes have anything to do with them?
That's what James Fowler and his research team at the University of California, San Diego, wanted to find out. Their study looked at six genetic markers in two longitudinal studies: the National Longitudinal Study of Adolescent Health and the Framingham Heart Study. Both these studies contained genetic data on friends.
DRD2, a gene associated with alcoholism, was found within clusters of friends. Another gene, CYP2A6, with a role in the metabolism of foreign substances, such as nicotine, was not found among friends. In fact, people with the CYP2A6 gene seemed to stay totally clear of each other.
These are two instances where genes seem to play a part in our friendships. Other instances have been found where individuals 'instinctively' do not couple with others that carry the same diseases. Are these genetic markers being expressed environmentally? Or socially, perhaps?
We are detecting certain genes in others "in some way, either consciously or unconsciously," Professor Fowler told BBC News. "We think that understanding the genotypes that underlie friendship may help us to understand more of that process."
BBC News, Proceedings of the National Academy of Sciences