Your friends may be your fourth cousins: US study
Washington: People tend to choose friends that are genetically similar to themselves, so much so that a person`s social circle could be made up of their fourth cousins, scientists said Monday.
The research is based on the Framingham Heart Study in the northeastern US state of Massachusetts, which contains both extensive genetic detail -- 1.5 million markers -- and information about friends and connections.
Scientists focused on 1,932 people and compared pairs of unrelated friends against pairs of unrelated strangers.
Those in the same social circles shared about one percent of their genes, much higher than the amount they shared with nearby strangers.
Friends tended to be about as related as people who share great-great-great grandparents.
"The increase in similarity relative to strangers is at the level of fourth cousins," said the study in the Proceedings of the National Academy of Sciences.
Even though sharing one percent of genes may not sound like a lot, co-author Nicholas Christakis, professor of sociology, evolutionary biology and medicine at Yale University, said "to geneticists, it is a significant number."
"We are somehow, among a myriad of possibilities, managing to select as friends the people who resemble our kin," he said.
Most of the people in the Framingham study were white and of European descent.
Researchers said they could tell from their analysis that the genetic ties among friends went above and beyond what would be expected among people of shared ancestry, or by people who tend to befriend those of the same ethnic group.
They could also tell that friends were most similar in genes affecting the sense of smell, and most different when it came to genes that affect immunity against various diseases.
Researchers do not fully understand how this happens.
But they said perhaps friends might be most easily made among those who enjoy the same smells, such as the aroma of a coffee shop.
On the other hand, the disparity in immune systems could foster survival in groups of friends by reducing the spread of dangerous pathogens.
More from India
More from World
More from Sports
More from Entertaiment
- Watch - IIT-Kharagpur develops superpower drone 'BHIM' that could aid soldiers in war zones
- Anti-Romeo squad launched: Has moral policing started in UP?
- What Muslims think about Ram Mandir issue?
- CM Yogi’s cleanliness drive: UP cops clean up police stations
- Martyrs' Day: Nation remembers Bhagat Singh, Sukhdev and Rajguru for their sacrifice
- Hukumdev Narain Yadav to be new Vice-President of India?
- 400 Trinamool Congress members including many TMC stalwarts join BJP in Tripura
- Bhagat Singh, Sukhdev, Rajguru were hanged on 23 March 1931 – This is how PM Modi paid tribute today
- Unable to meet educational expenses, Muslim girl writes to PM Narendra Modi – Know what happened next
- Yogi Adityanath took THESE 20 big actions in just 75 hours after becoming UP CM