Thomas Gibson’s first field research project concerned the relationship between the egalitarian and pacifist values of the Buid, an indigenous people inhabiting the highlands of Mindoro, Philippines, and the hierarchical and aggressive values of the Christian and Muslim societies found in the lowlands (1986).  He followed this up with a comparative study of attitudes toward violence and aggression among shifting cultivators throughout Southeast Asia, showing that they varied according to historical exposure of different groups to raiding by lowland and coastal societies (1990). This study inspired his next field research project, a study of the formation of predatory states among the Makassar of South Sulawesi, Indonesia in relation to peer polities around the Java Sea in the period before 1600 CE (2005).  He then turned his attention to the shifting relationships among social, political and religious centers of authority in Southeast Asia from 1300 to 2000 (2007). 

In a forthcoming monograph on Subjectivity and Sovereignty in Islamic Southeast Asia: Polyontological Practices among the Makassar, he will examine the political implications of life cycle rituals, Islamic devotional practices and mass schooling.  He plans to follow this trilogy of monographs on Islam in Indonesia with a comparative study of the development of Islamic, Hindu and Buddhist nationalism in the countries surrounding the Indian Ocean. In 2009, he returned to his original research interest by helping to organize a comparative study of ten egalitarian societies in Malaysia, Indonesia and the Philippines, which resulted in an edited volume (2011).  This study has led to a new project concerning the history of the movement for the rights of indigenous peoples, both in the Philippines and around the world.