Following his master's research on the Chagossians in Mauritius, he moved northwards to carry out doctoral work on mimesis, custom and belonging on the Comorian island of Ngazidja; since then he has worked on movements of people between the Comoros, Zanzibar and Hadramawt. His work on identity among mobile communities of Arab origin in East Africa, and on the Comorian and Hadrami diasporas, has been funded by an ARC Postdoctoral Fellowship (2005-2007) and an ESRC Mid-Career Fellowship (2009-2011). From 2011 to 2015 he was part of the Leverhulme-funded Oxford Diasporas Programme; his project, 'Converging cultures: the Hadrami diaspora in the Indian Ocean', was concerned with social networks among Hadramis in Eastern Africa and the Arabian peninsula.
His research interests have remained focused on identity and ethnicity, expanding to include migration, globalisation and notions of home and belonging, as well as age systems.
He has held positions at the University of New South Wales, Macquarie University, SOAS and the University of Oxford. He was a Research Fellow at the Max Planck Institute for Social Anthropology in Halle before coming to the Max Planck Institute for the Science of Human History. In January 2017 he will take up a position at Martin Luther University in Halle leading a DFG funded research project entitled “Remembering, forgetting, imagining: identity strategies in Mayotte”.
He is co-coordinator of the AEGIS Collaborative Research Group Africa in the Indian Ocean, committee member and webmaster of the SwahiliWeb resource site, and moderator of the Indian Ocean Studies mailing list.