The Evolution of Social Relationships and Strategies Across the Lifespan

Abstract. In this work, we unveil the evolution of social relationships across the lifespan. This evolution reflects the dynamic social strategies that people use to fulfill their social needs. For this work we utilize a large mobile network complete with user demographic information. We find that while younger individuals are active in broadening their social relationships, seniors tend to keep small but closed social circles. We further demonstrate that opposite-gender interactions between two young individuals are much more frequent than those between young samegender people, while the situation is reversed after around 35 years old. We also discover that while same-gender triadic social relationships are persistently maintained over a lifetime, the opposite-gender triadic circles are unstable upon entering into middle-age. Finally we demonstrate a greater than 80% potential predictability for inferring users’ gender and a 73% predictability for age from mobile communication behaviors.