Rethinking complexity in facial communication systems

This project is now closed. The details below are for information purposes only.

This PhD will be based in the Department of Psychology Centre for Comparative and Evolutionary Psychology and will be supervised by Dr Jérôme Micheletta, Professor Bridget Waller and Dr Julie Duboscq. The successful candidate will work closely with a Postdoctoral Research Fellow as well as the Principal Investigator (PI) and collaborators on the project.

The project is funded by the Leverhulme Trust and is available to UK and EU students only. The funding covers tuition fees and an annual maintenance grant in line with the RCUK rate (£15,009 for 2019/20) for three years.

This project seeks to develop a new theoretical and methodological framework based on the Facial Action Coding System (FACS) and Social Network Analysis, and test the hypothesis that social complexity drives the evolution of facial communication complexity by comparing four closely related species characterised by different degrees of social complexity: rhesus, long-tailed, Barbary, and crested macaques.

Humans and other primates are capable of incredibly subtle and meaningful facial movements that are important channels of communication. Current evidence suggests that species characterised by more complex social systems (e.g. large social groups, individualised, diverse and long-term relationships) have more complex communication systems, in order to deal with their complex social lives.

Testing this hypothesis is hampered by the dominant theoretical approach which conceptualises facial expressions as static configurations of the face, reflecting categorical internal states such as anger or fear (i.e. universal emotions). Scientists are trying to approximate complexity by forcing a species’ facial behaviour into these arbitrary categories, resulting in a number (usually between two and ten) used to compare species. We believe that this arbitrary classification is highly subjective, and does not account for the subtlety, variability and dynamism of communication via the face. First, the expressions may differ anatomically. Second, the expressions might blend with others, incorporate additional muscle movements at times, and link with others in complex sequences. Third, the expressions may not have the same duration and temporal dynamics.