It is well established that people form friendships based on shared similarities, hence the saying, “birds of a feather flock together.”
But, recent research by Drs. Carolyn Parkinson, Adam Kleinbaum, and Thalia Wheatley takes the connection between friends a step further. Specifically, they used functional magnetic resonance imaging (fMRI) to scan subjects’ brains while they watched a series of short videos. Summarized nicely in this NY Times article, they found that the brains of close friends respond similarly as they view the videos: “the same ebbs and swells of attention and distraction, the same peaking of reward processing here, boredom alerts there.” In other words, friends’ brains responded in remarkably similar ways.
Dr. Parkinson explains these findings, stating: “Our results suggest that friends might be similar in how they pay attention to and process the world around them...That shared processing could make people click more easily and have the sort of seamless social interaction that can feel so rewarding.”
So, the roots of friendship extend even deeper than previously suspected, suggesting that friends have “an ineffable shared reality.”