Friends are as related as fourth cousins or people who share great-great-great grandparents on average, a University of California (UC) and Yale University study has found. This translates to about 1% of our genes.
“One percent may not sound like much to the layperson, but to geneticists it is a significant number,” said UC medical genetics professor James Fowler. “And how remarkable: Most people don’t even know who their fourth cousins are. Yet we are somehow, among a myriad of possibilities, managing to select as friends the people who resemble our kin.”
The study is a genome-wide analysis of nearly 1.5 million markers of gene variation, and relies on data from the Framingham Heart Study. The Framingham dataset is the largest the authors are aware of that contains both that level of genetic detail and information on who is friends with whom. The researchers focused on 1,932 unique subjects and compared pairs of unrelated friends against pairs of unrelated strangers. The same people, who were neither kin nor spouses, were used in both types of samples. The only thing that differed between them was their social relationship. In the study, Fowler develops a “friendship score,” which they used to predict who will be friends at about the same level of confidence that scientists currently have for predicting, on the basis of genes, a person’s chances of obesity or schizophrenia.
Shared attributes among friends or functional kinship can confer a variety of evolutionary advantages. In the simplest terms: If your friend feels cold when you do and builds a fire, you both benefit.
(News Update Source: Times of India)