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.
AFP RELAXNEWS
Tue Jul 15 2014
Researchers found that the genetic ties among friends went above and beyond what would be expected among people of shared ancestry. -AFP Photo
AWANI Pagi: Perang Israel-Iran: Perang alaf baharu?
Diskusi 8.30 pagi Sabtu bersama Jumaat bersama Pakar Hubungan Antarabangsa, Prof Dr. Ahmad Marthada Mohamed mengenai kemungkinan lebih buruk boleh dijangkakan di rantau Asia Barat selepas Israel bertindak melancarkan peluru berpandu dan membedil bandar Isfahan di Iran semalam.
Buang dua ekor itik kerana bimbang nasib malang
Siok Hui meletakkan kedua-dua itik itu dalam sebuah kotak sebelum ditinggalkan di Hutan Simpan Bukit Timah ketika kejadian pada 2020.
Piala FA Inggeris: Status Erling Haaland masih tanda tanya
Pep Guardiola mendedahkan bahawa pemain berusia 23 tahun itu meminta untuk dikeluarkan tanpa memberi alasan yang kukuh.
Anwar hadir selesai kemelut MPN Sabah
Beliau mempengerusikan perjumpaan tersebut yang dipercayai bagi menyelesaikan kemelut politik PKR di negeri ini.
Piala Asia B-23: Vietnam intai peluang benam Malaysia, layak ke suku akhir
Vietnam mencari peluang untuk memastikan slot ke suku akhir Piala Asia B23 apabila berdepan Malaysia malam ini.
AWANI Pagi: Berita tumpuan & menarik di astroawani.com [20 April 2024]
AWANI Pagi bersama Geegee Ahmad & Azib Zikry membincangkan keperluan pengenalan Skim Kemalangan Bukan Bencana Kerja (SKBBK) di mana Presiden Kongres Kesatuan Sekerja Malaysia (MTUC), Mohd Effendy Abdul Ghani akan menekankan bahawa langkah proaktif itu adalah untuk melindungi hak-hak pekerja khususnya apabila melibatkan kemalangan jalan raya di luar waktu bekerja.
Lelaki bertindak bakar diri di luar mahkamah New York
Max Azzarello yang berasal dari St. Augustine, Florida, dilaporkan telah diselamatkan dan berada dalam keadaan kritikal.
[TERKINI] Ketua Polis Negara paling lama meninggal dunia
Bekas Ketua Polis Negara, Tun Mohamed Hanif Omar, meninggal dunia pada usia 85 tahun di kediamannya di Shah Alam pada 2.15 pagi Sabtu.
Pasangan suami isteri tidak sangka dua kali tolak tawaran, masih ada rezeki tunai haji tahun ini
Selepas surat tawaran berada di dalam tangan, dia dan isteri giat membuat persiapan demi memastikan mereka memperoleh haji yang mabrur.
Lelaki bertindak bakar diri di luar Mahkamah New York
Seorang lelaki bertindak membakar dirinya di luar mahkamah New York di mana perbicaraan bagi kes bekas presiden Amerika syarikat Donald Trump sedang berjalan