Scientists Discover That Matching Brain Waves Can Predict Friendships

"Friends process the world around them in exceptionally similar ways."

Matching tattoos or BFF bracelets are so passé. If you’re really best friends with someone, scientists say you’ll have matching brain waves. Researchers came to this conclusion in January in an unprecedented study on the neural connections of people existing within a real social network. In their Nature Communications paper, they show compelling evidence of a phenomenon called “neural homophily” — which is what you might imagine you share with your bestie.

The fact that people who are socially close have extremely similar patterns of brain activity after watching the same stimuli indicates that we are extremely similar to our friends in the ways in which we perceive and respond to the world. Birds of a feather don’t just flock together — they are bonded by the ways their brains interpret life.

This story is #13 on Inverse’s 25 Most Surprising Human Discoveries Made in 2018.



Human social networks, the Dartmouth College and the University of California, Los Angeles co-authors write, are “overwhelmingly homophilous.” In other words, people usually end up friending people who share both physical attributes (like age and gender) and life experiences. It’s previously been assumed that like-minded social groups evolved to become the norm because small hunter-gatherer bands needed similarities, not differences, to unite them together during hard times.

What the team wanted to know if whether these similarities extended beyond surface-level traits.

So, in this study, 280 graduate students of varying degrees of friendship watched a set of video clips while their brains were scanned with an fMRI machine. The closest friends had the most similar neural activity patterns — blood flowed to different regions of the brain in the same way — while less closely linked individuals, like friends of friends, had less similar patterns. These changes in neural responses were evident in regions of the brain tied to emotional responses, high-level reasoning, and attention.

“Neural responses to dynamic, naturalistic stimuli, like videos, can give us a window into people’s unconstrained, spontaneous thought processes as they unfold,” lead author and UCLA psychology professor Carolyn Parkinson, Ph.D.explained. “Our results suggest that friends process the world around them in exceptionally similar ways.”

As 2018 winds down, Inverse is highlighting 25 surprising things we learned about humans this year. These stories told us weird stuff about our bodies and brains, uncovered insights into our social lives, and illuminated why we’re such complicated, wonderful, and weird animals. This story was #13. Read the original story here.

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