Primates live in diverse social organizations that differ markedly in their sizes and composition. Primates also vary substantially in the degree to which they express sexual dimorphism in body mass and secondary sexual traits (ornaments). In this seminar I explore the evolutionary drivers of sexual dimorphism in body size and ornamentation in primates living in large multi-tiered societies. Particular emphasis is placed on how living in such societies (wherein conflict may arise frequently and individual recognition is limited) necessitates selection for amplified signals of status or attractiveness. Cyril completed his PhD in biological anthropology at the University of Zurich/Switzerland in 2009. His PhD research involved a pioneering 20-month study on the socioecology of wild snub-nosed monkeys in China. This project was implemented in close collaboration with academics and students at the Chinese Academy of Sciences in Beijing. Upon completion of his PhD, he immediately commenced work as a postdoctoral fellow at the Max Planck Institute for Evolutionary Anthropology in Leipzig/Germany. He spent 18 months at the Karisoke Research Center in Rwanda (which is managed by the Dian Fossey Gorilla Fund International), collecting data on the feeding ecology of a critically endangered mountain gorilla population in Volcanoes National Park. Cyril was offered a tenure-track Assistant Professor position at the School of Anatomy, Physiology and Human Biology (now School of Human Sciences) at UWA in October 2011, took up the position in April 2012 and was granted tenure in October 2014. Cyril’s primary research interests lie at the interface of behavioural ecology and evolutionary anthropology and include the evolution of primate/human sociality and the mechanisms underlying social cohesion. His particular interests revolve around the evolution of meta-group social organization which describes cases in which individuals of different social units interact and collaborate to varying degrees. Cyril is involved in ongoing field research projects on snub-nosed monkeys in China as well as mountain gorillas, chimpanzees and colobus monkeys in Rwanda.