Friends’ Brain Patterns Look the Same When They Think of Each Other
Fri, December 9, 2022

Friends’ Brain Patterns Look the Same When They Think of Each Other

A new study from Ohio State University revealed that the brain patterns of friends look the same when they think of each other. / Photo by: Dennis Magati via Pexels


Maybe the saying “birds of a feather flock together” is true after all in friendships. Not because these friends share the same taste or interests but because they just simply understand each other. A new study from Ohio State University revealed that the brain patterns of friends look the same when they think of each other, but such patterns will be different when they think of someone else.

Brain Activity for Friend’s Identity

This means that when a person thinks of the personality of their friend, they will have remarkably similar brain activity patterns to that friend when they think about themselves. To come up with such findings, the researchers recruited 11 people who were friends with each other to varying degrees. These subjects were in a pretty close group as they were from the same academic program and spent time together at school and outside of it.

Co-author and the Ohio State University’s assistant professor Dylan Wagner explained that in one session, they asked the participants to rate the other 10 separately based on their personality traits. In another session, the 11 subjects had the same evaluations while they were in a functional magnetic resonance imaging scanner.

Testing the Participants Based on 48 Traits

Images of each participant’s brain activity were taken through the fMRI. In the second session, each of them was asked to rate each of their friends and also themselves on 48 varying traits, including nice, punctual, helpful, clumsy, fashionable, enthusiastic, overcritical, trustworthy, cold, lazy, sad, and lonely. The researchers saw a brain activity, particularly in the medial prefrontal cortex. It is a brain region that has been connected to personality expression, moderating social behavior, decision-making, and planning complex cognitive behavior.

The study revealed that the brain activity of each participant looked the same when their friends were evaluating them like it was their own brain activity. Wagner added that in order for us to perceive one friend, our neural representations of that friend or our brain activity patterns for their personality has to match such pattern in that friend’s brain as they are thinking about themselves. 

However, the researchers noted that their findings only showed the aggregate data and it was focused on taking the brain patterns of the friends while averaging another friend. This research approach was usually taken in non-fMRI research when comparing the consensus judgments of friends.

Research head Robert Chavez, who is also an assistant professor of psychology at the University of Oregon, added that the result was somehow “not surprising.” His reason was that each of our friends gets to see every now and then a different side of us. So, when the personality is considered together, it becomes a better approximation of how we see ourselves than the other person individually.

A larger version of the recent round-robin study will be conducted by the team and they will include other groups, such as personal friends and work friends.


Images of each participant’s brain activity were taken through the fMRI. / Photo by: Photo by: zlikovec via 123rf


How Neural Responses Predict Friendship

Last year, another study titled “Similar neural responses predict friendship” explained that human social networks are homophilous—the tendency of people to have ties with people who are similar to themselves in socially significant ways. This could be in terms of physical attributes such as gender and age. For this study, social psychologists and brain researchers at Dartmouth College studied the brains of 42 students and checked their reactions while they were watching retro videos like “America’s Funniest Home Videos.”

Their MRI scans revealed that friends who watched the same clips reacted in similar ways, such as the same brain regions lit up, particularly those associated with affective processing, memory, learning, and motivation. The researchers noted that the brain reaction patterns were strikingly similar that they can predict who among their participants were friends with each other. In addition, people who were not friends didn’t have the same reactions to the same videos and more divergent if they were from separate social groups.

Lead author Carolyn Parkinson said via Business Insider, an American financial and business news, that “friends process the world around them in exceptionally similar ways.” The authors also wrote that having close friends who share the same brain activity as ours can be “rewarding” as it reinforces our own interests, opinions, and values.

Friendship by the Numbers

Assumption College’s director of the Laboratory for Cognitive and Affective Science Sarah Rose Cavanagh Ph.D., who was not a part of the two studies mentioned above, illustrated how friendship works on average by the numbers. From your ego or self as the first circle, the second circle (1.5) represents the number of intimate partners a person needs. These are people who can tell just by looking at you when something bad happens or you are stressed. Then, the third circle (5) encompasses the number of very good friends whom you can rely on. The fourth circle (50) represents your social capital. The limit would be around 150 as your maximum functional social network. Beyond 150, it would be difficult to maintain relationships with them in a way that will contribute to your emotional and physical well-being.