A study released Monday by the U.S. National Academy of Sciences found that we share 1% of genes with our friends. “Birds of a feather flock together” is scientifically verified.
We say that we do not choose our family but that we choose our friends. However, according to a study published Monday in the United States by the National Academy of Sciences, the genes of our friends are in part similar to ours. “We have more DNA in common with the people we choose as friends rather than complete strangers,” said James Fowler, professor of genetics at the University of San Diego and co-author of the study with his Brother Nicholas Christakis, professor of sociology, evolutionary biology and medicine at Yale University (Northeastern United States). By carefully observing the relationships that individuals maintain within the same social circle, the two researchers found that, to use the famous proverb, “who look alike, assemble”. And, of course, they wanted to know why.
1% of genes in common
To do this, Fowler and Christakis relied on a large database – the Framingham Heart Study – containing nearly 1.5 million genetic markers. They then selected a group of 1,932 individuals, most of them from Europe. Two different pairs having no family relationship between them are studied: the first are friends, the second do not know each other. “1% of people from the same social circle share similar genes”, establish the researchers. A significant number according to them. Indeed, this percentage of genes would be equivalent to a relationship of cousins in the fourth degree.
The survey also shows “that our physical condition does not seem to depend only on our own genetic makeup, but also on that of our friends”, according to Nicholas Christakis. Finally, solidarity between friends takes a hit. “If one of the two friends is cold, the other will make a fire which will also warm him up, which in the end will be beneficial for both”, explains the professor.
Based on the results of the study, Fowler and Christakis conclude that it is “possible to predict social behaviors from the genes of individuals, as reliably as it is possible to establish genes carrying them. obesity or schizophrenia. “
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