Your closest friends often share similar DNA with you, just like distant relatives, according to a study from Yale University and UC San Diego.
A study published in the Proceedings of the National Academy of Sciences (PNAS) found that close friends are genetically more similar than strangers. On average, they share about 1% of their DNA, which is comparable to the genetic similarity between fourth cousins.
Researchers Nicholas Christakis and James Fowler suggest that people may unconsciously form friendships with those who are biologically similar, influencing everything from shared interests to DNA.
This is precisely why some societies never collapse.
