Can you finish your best friend’s sentences? Do you know beforehand if they will laugh at a particular joke? Do they love every gift you give them?
If so, there may be chemicals involved – neurochemicals, to be precise. A recent scientific study demonstrates that close friends often have similar neural responses to outside stimuli. The results add to a growing body of evidence that friends often share mental and physiological traits.
The new study, published earlier this year in the journal Nature Communication, used videos to explore the neural connection between friends. A group of 42 graduate students drawn from a social network of 279 students was asked to watch several videos on a variety of topics – science, music, comedy, politics – while hooked up to a fMRI scanner.
The researchers found that the closer the friends, the more similar their brains reacted to the videos. Those similarities faded as the human connection weakened. Friends of friends had fewer neural similarities, third-ring friends even fewer.
Here’s the scary part, especially in this age of Facebook data-scraping: The researchers were able to identify friends using an algorithm. Once this digital sleuth was taught to recognize patterns of neural activity among friends of varying degrees, it was able to determine the degree of closeness between other study participants.
“Open the pod bay doors, Hal.”
The study suggests that friends process outside information in a similar manner, especially when it pings parts of the brain associated with motivation, emotion, attention, and assessing the mental state of others.
“Neural responses to dynamic, naturalistic stimuli, like videos, can give us a window into people’s unconstrained, spontaneous thought processes as they unfold,” said lead author Carolyn Parkinson. “Our results suggest that friends process the world around them in exceptionally similar ways.”
The new study does not address whether friends somehow influence each other’s neural responses, or if people with similar brain functions tend to become friends.
A clue to that mystery might be found in other studies that have found common genotypes and personality traits among close friends. Still, more research has confirmed that friends tend to flock together along such demographic lines as race, religion, education, job, and gender.
Still, these new findings are really…
OMG, I knew you were going to say that!
Check Out: Why Good Friends Keep Us Young As We Age