Faculty & Research
The School

Persistent features of social networks

Key ideas 

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.

Read the published article

Read the research article in Proceedings of the National Academy of Sciences (PNAS).


Media mentions

"The only thing constant about friendship may be the number of your friends" Science/AAAS
"Oxford confirms something we all know - social media can't give you more friends" VentureBeat
"Soziale netzwerke: neue freunde verdrängen alte freunde" Spiegel Online
"One in, one out: study shows how people put a limit on their social networks"
"Despite social networks like FaceBook and Twitter, most people will only ever have a handful of good friends" The Independent
"People demote old friends as new ones arrive" Business Standard
"Our social networks remain very small" Digital Journal 
"Despite social media connections, most people only have a few 'close friends': study" New York Daily News
"Science may explain why your friendships fall apart" Huffington Post
"Despite social media most of us have only a few good friends, study" CTV News
"Scientists may have decoded your social circle" The Atlantic, CityLab


Download the poster

Oxford Saïd authors




Felix Reed-TsochasSaïd Business School




E. A. Leicht, Saïd Business School (now at FaceBook)




Eduardo LópezSaïd Business School


Other authors




Sam G. B. Roberts, University of Chester




Robin I. M. Dunbar, University of Oxford




Jari Saramäki, Aalto University School of Science