Similar neural responses predict friendship

• Published in: Nature communications Vol. 9; no. 1; pp. 332 - 14
• Main Authors: Parkinson, Carolyn, Kleinbaum, Adam M., Wheatley, Thalia
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 30-01-2018; Nature Publishing Group; Nature Portfolio
• Subjects: 59/36; 631/378/2645; 631/378/2649; 631/477/2811; Adolescent; Adult; Analogies; Brain - anatomy & histology; Brain - diagnostic imaging; Brain - physiology; Female; Friends - psychology; Friendship; Functional magnetic resonance imaging; Human behavior; Humanities and Social Sciences; Humans; Interpersonal Relations; Magnetic Resonance Imaging; Male; multidisciplinary; Science; Science (multidisciplinary); Sensory integration; Similarity; Social Networking; Social networks; Social organization; Viewing
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-017-02722-7

Human social networks are overwhelmingly homophilous: individuals tend to befriend others who are similar to them in terms of a range of physical attributes (e.g., age, gender). Do similarities among friends reflect deeper similarities in how we perceive, interpret, and respond to the world? To test whether friendship, and more generally, social network proximity, is associated with increased similarity of real-time mental responding, we used functional magnetic resonance imaging to scan subjects’ brains during free viewing of naturalistic movies. Here we show evidence for neural homophily: neural responses when viewing audiovisual movies are exceptionally similar among friends, and that similarity decreases with increasing distance in a real-world social network. These results suggest that we are exceptionally similar to our friends in how we perceive and respond to the world around us, which has implications for interpersonal influence and attraction.
Though we are often friends with people similar to ourselves, it is unclear if neural responses to perceptual stimuli are also similar. Here, authors show that the similarity of neural responses evoked by a range of videos was highest for close friends and decreased with increasing social distance.