Humans are social species that are constantly involved in complex relationships, reacting to the actions of others, and intentionally or unintentionally changing our own behavior. Personality traits reflect the behavioral pattern of an individual's response to the environment, which also includes social behavior. In addition, the brain is also an important factor when discussing social networks. The brain provides biological mechanisms for human behavior, while social networks provide external triggers for these behaviors. Linking personality traits and brain activity to social networks can help us better understand the structure of group relationships, improve our understanding of individual human beings, and help us better predict individual social behaviors and find the rules of information transmission in interpersonal relationships.
From the perspective of a network, we collected nine social networks from 94 undergraduate students in the same grade according to their different social needs. We used the graph theory and resting-state functional magnetic resonance imaging to explore the influence of personality traits on social networks based on individual popularity and closeness between individuals and the relationship between the similarity of brain resting-state functional connectivity and social distance between individuals. Specifically, regression analysis was carried out, with personality traits as the independent variables and the different degrees of social networks as the dependent variables. Then, a correlation analysis was performed for the social distance and similarity of personality traits. Finally, the correlation between the similarity of the brain networks and social distance was calculated.
The results showed that (1) individuals with high conscientiousness were more popular in social networks requiring “trust” traits, while individuals with high agreeableness were more popular in social networks requiring “fun” traits. These findings showed that in the same group, there are different social networks according to social needs, and the popularity of individuals in different social networks was not similar as it will be affected by the corresponding personality traits; (2) In the social networks requiring “shared interests & values”, personality similarity and social distance between individuals were significantly negatively correlated. Personality similarity promotes interpersonal communication between individuals, which may be realized through interpersonal attraction induced by the similarity of values and interests; (3) In the same social network, there is a significantly negative correlation between similarities in functional connections (FCs) and social distance among individuals, and these FCs are mainly concentrated in the frontoparietal task control network and the dorsal attention network. The similarity of resting brain FCs among individuals may promote interpersonal communication, possibly due to the similarity of individuals in cognitive control and environmental processing bias, which increases the interpersonal attraction and shortening the social distance between individuals.
The results revealed the influence of personality traits on the structure of different social networks, the relationship between personality trait similarity among individuals, and the similarity between resting brain networks and social distance, which has important implications for understanding the structure of social networks, the formation rules, and the information transmission rules among them. In addition, this study discussed the relationship between the similarity of resting-state FC and social distance, providing new evidence for studies on brain synchronization in interpersonal communication and brain imaging evidence for the study of the relationship between the similarity of personality traits and social distance.