“The Social Brain”, drawn by Bronwyn Tarr and designed in collaboration with Rafael Wlodarski. Browyn Tarr & Rafael Wlodarksi
“The Social Brain”, drawn by Bronwyn Tarr and designed in collaboration with Rafael Wlodarski.

For the past two decades, we have been engaged in a series of projects designed to understand, within a broad psychological and evolutionary perspective, the evolution of sociality in primates (including humans). These have focussed on understanding both the constraints on social group size (the Social Brain Hypothesis and the time budget models) and the structure and dynamics of contemporary human social networks. In the process, we have begun to understand the nature of dyadic relationships and the cognitive and time constraints that limit the number of relationships we can have.

There are two major issues that arise out of this work that we are now investigating. One is the cognitive and neurophysiological underpinnings of social bonding (based on the dual process cognition-plus-endorphins model of primate social bonding); the other is the implications these have for large scale social cohesion at the community level and above. We continue to explore the evolution of the primate (and human) brain and the selection factors that have acted on it through geological time, seeking to understand both how human sociality arose historically in terms of the ecological selection pressures and what constraints have acted on it. At the same time, we seek to determine the behavioural, cognitive and neurobiological mechanisms that underpin human sociality.

 “While Dunbar has long been an influential scholar, today he is enjoying new found popularity with a particular crowd: the Silicon Valley programmers who build on-line social networks.”  - Drake Bennett, Blomberg Business Week

We have collaborations with computer scientists working on Big Data projects (e.g. phone call databases), as well as with Palaeolithic archaeologists (on human social evolution), historians (on the Icelandic Vikings) and literary theorists (experimental studies on cognitive aspects of drama and storytelling). We combine insights from these studies with a variety of mathematical modelling approaches to explore social evolution in primates and humans. Our findings are being used in the design of on-line networking software, and they have implications for how businesses and other public organisations are structured.

We are funded by a European Research Council Advanced Research Grant awarded to Professor Robin Dunbar.





Selected publications

News Highlights


28 October 2015, research by Bronwyn Tarr and Dr. Eiluned Pearce on the effects of singing and bonding was featured in the national news and media.

The Siemes Curiosity Project blog featured a video of Dr. Rafael Wlodarski discussing the role of genetics in social bonding, recorded at the British Science Festival in Bradford during data collection for the Genetics of Human Sociality project.

14 October 2015, Dr. Eiluned Pearce was featured in a Naked Genetics podcast recorded at the British Science Festival, speaking about her ongoing Genetics of Human Sociality project. 

19 May 2015, Dr. Anna Machin's research finds that fathers who want to be more involved with their newborn children feel held back by lack of support from health staff, government and society. Read about it here.

17 April 2015, Professor Robin Dunbar was featured in short Financial Times video on the the future of friendship in the digital world.

Related research themes