A: Their genetic relatedness to you.
A new study out in PNAS this week suggests that you may have even more in common with your friends than you think. In particular, you are more likely to share your sense of smell.
“People often talk about how their friends feel like family. Well, there’s some new research out that suggests there’s more to that than just a feeling. People appear to be more like their friends genetically than they are to strangers, the research found. Some of the genes that friends were most likely to have in common involve smell. “We tend to smell things the same way that our friends do,” Fowler says. The study involved nearly 2,000 adults.”