The saying that friends are the family you choose may be more accurate than you thought. A study shows that people are likely to pick friends who are genetically similar to themselves – so much so that friends tend to be as alike at the genetic level as a person’s fourth cousin (people who have great-great-great grandparents in common).
People were most similar to their friends in olfactory genes, which involve the sense of smell, and least similar in immune system genes. People who like the same smells tend to be drawn to similar environments, where they meet others with the same tendencies. The opposite was true for genes controlling immunity; friends were more likely than strangers to have different genetic defences against various diseases. This may be because it helps to reduce the likelihood of epidemics if friends are resistant to different illnesses.
Researchers suspect that this trait, called ‘functional kinship’, is rooted in human evolution. Early human beings may have formed groups if they were genetically suited to certain environments, or had similar likes and dislikes, e.g., those with a similar susceptibility to the cold may have helped each other build a fire. It may have also been because some genetic attributes only work if you have someone to share it with. The first, most intelligent humans to develop speech would have grouped together with others with the small skill.
Picture Credit : Google