Your friends and you may have more in common than you think. According to a study published yesterday in Nature Communications, friends tend to have similar neural responses to real-world stimuli and this similarity increases depending on the closeness of the relationship.
The study, done at Dartmouth College, analyzed a group of 280 graduate students who were asked to report on their social network. Researchers estimated the social distance between the students based on their responses. Forty-two of the students were selected to undergo fMRI while watching a series of videos. The order of the videos and instructions were the same for all participants.
Comparing brain responses in 80 anatomical regions of interest, the researchers found significant similarity in the brain responses of friends. They were also able to determine relationship closeness based on the extent of similarity in the responses. These similarities remained even when controlling for variables such as left-handed- or right-handedness, age, gender, ethnicity and nationality.
"We are a social species and live our lives connected to everybody else. If we want to understand how the human brain works, then we need to understand how brains work in combination-- how minds shape each other," explained senior author Thalia Wheatley, an associate professor of psychological and brain sciences at Dartmouth.
In the future, the researchers hope to be able to continue the research to determine whether people naturally gravitate people who share a world view or if that view changes as you they become closer.
Image: Social network. The social network of an entire cohort of first-year graduate students was reconstructed based on a survey completed by all students in the cohort (N = 279; 100% response rate). Nodes indicate students; lines indicate mutually reported social ties between them. A subset of students (orange circles; N = 42) participated in the fMRI study. Image courtesy of Carolyn Parkinson.