Our current issue reflects the Journal's ongoing promotion of focused explorations of specific themes, issues, or topics in Southeast Asian Studies. We welcome special issue proposals that critically re-evaluate or expand our understanding of the region conceptually, methodologically, or empirically. Future special issues in the pipeline will highlight research drawn from international workshops and conferences, regional institutions, and occasional solicited compilations as part of our commitment to increase the access, circulation, and exchange of scholarship on the region. This special issue of JSEAS, edited by Warwick Anderson and Ricardo Roque, explores the role and legacy of colonial science in the ethno-historical construction of ‘human difference’ in the ‘imagined racial laboratory’ of Island Southeast Asia. The guest editors provide an Introduction to the issue in the pages that follow.