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
- Heat ave continues in India, death toll climbs to over 1,400
- UP: Man chops off wife's nose, hair for dowry
- Megastar Amitabh Bachchan slapped with Rs 1 crore notice
- Zee Media Exclusive: The plight of yoga expert Tejaswi Sharma
- Kenyan lawyer offers to marry Barack Obama's daughter Malia
- Woman denied flat in Mumbai for being a Muslim
- 4 Indians in Forbes' 100 most powerful women list
- Gujjar stir: HC asks Rajasthan govt to clear rail track, roads
- Maggi likely to face ban in India!
- Salman Khan accident files burnt in Mantralaya fire
- AIB: The 'Third Gender's right to dignity'
- Gujjar stir: HC asks Rajasthan govt to clear rail track, roads- Part II
- TERI panel finds RK Pachauri guilty in sexual harassment case
- Rajasthan: High Court raps Chief Secy, DGP for failing to end Gujjar agitation
- Priyanka, Ranveer talk about their film 'Dil Dhadakne Do'
- CBSE Class 10 (Class X Board) Result 2015 on cbse.nic.in, cbseresults.nic.in at 2 pm
- Sonia Gandhi 'unconstitutional authority' during UPA: PM Narendra Modi
- Hours after attacking NDA govt, Manmohan Singh meets PM Narendra Modi
- Check cbseresults.nic.in, cbse.in for CBSE Class 10 X Board Result at 2 pm
- PMO website revamped, now send e-mail to PM Modi directly
- GUJCET Results 2015 declared on gseb.org
- Centre moves SC against Delhi HC order on LG's powers; hearing on Friday
- Pakistan break Team India's long-standing ODI record at home soil
- Gujjar agitation: Centre sending additional forces to vacate rail tracks, say sources
- Rahul Gandhi takes another dig at NDA govt, says Manmohan gave lessons on economy to PM Modi
- Islamic State attracts young recruits with free honeymoon, stipend for family
- MSBSHSE Class XII HSC results 2015: Maharashtra Class 12th Board results declared on mahresult.nic.in
- Log on to cbseresults.nic.in, cbse.nic.in at 2 pm for Class 10th Result 2015
- Former Bihar CM Jitan Ram Manjhi meets PM Modi, triggers tie-up speculation