Persistence of social signatures in human communication

• Published in: Proceedings of the National Academy of Sciences - PNAS 2014-01, Vol.111 (3), p.942-947
• Main Authors: Saramäki, Jari, Leicht, E. A., López, Eduardo, Roberts, Sam G. B., Reed-Tsochas, Felix, Dunbar, Robin I. M.
• Format: Article
• Language: English
• Subjects: Adolescent; Adolescent Development; Cell Phone; Cell phones; Communication; Communication patterns; Ego; Emotional intimacy; Emotions; Female; Friendship; Humans; Interpersonal communication; Interpersonal Relations; Longitudinal Studies; Male; Models, Statistical; Multilevel models; Personal relationships; Physical Sciences; Questionnaires; Regression Analysis; Signatures; Social evolution; Social networking; Social networks; Social Sciences; Social Support; Students; Surveys and Questionnaires; Time signatures; United Kingdom; Universities; Young Adult
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.1308540110

The social network maintained by a focal individual, or ego, is intrinsically dynamic and typically exhibits some turnover in membership over time as personal circumstances change. However, the consequences of such changes on the distribution of an ego’s network ties are not well understood. Here we use a unique 18-mo dataset that combines mobile phone calls and survey data to track changes in the ego networks and communication patterns of students making the transition from school to university or work. Our analysis reveals that individuals display a distinctive and robust social signature, captured by how interactions are distributed across different alters. Notably, for a given ego, these social signatures tend to persist over time, despite considerable turnover in the identity of alters in the ego network. Thus, as new network members are added, some old network members either are replaced or receive fewer calls, preserving the overall distribution of calls across network members. This is likely to reflect the consequences of finite resources such as the time available for communication, the cognitive and emotional effort required to sustain close relationships, and the ability to make emotional investments.