Interplay between Social Selection and Social Influence on Physical Proximity in Friendship Formation

Abstract

People form social relationships based on certain characteristics they possess, called social selection. When people change their social behavior due to interaction with others, social influence is at work. Current friend recommendation systems are mainly based on common friends and similar profile characteristics, therefore the system may recommend unknown people. Recent advances improve the quality of friend recommendations by using shared content and interactions such as co- authored papers, patents, and comments, but neglect the physical interactions to associate how you may know that person. In this paper, the interplay between social selection and social influence on physical proximity in friendship formation is quantified in a mobile location- based social network deployed in an academic conference. Encounter is used to measure and record physical proximity between user pairs, then a friend recommendation system is built that uses these encounters to specify the reason why this person should be added as a friend. The cumulative average duration and average frequency of encounters are analyzed, before and after sending the friend request. The results present weak social selection and strong social influence on physical proximity in friendship formation and the reasons are explained. This work helps to improve the design implementation of friend recommendation in physical environments.