This paper problematises the notions of public or common good as weighed against individual sovereignty in the context of medical research by focusing on genetic research. We propose the notion of collective good as the good of the particular collective in which the research was conducted. We conducted documentary and interview-based research with participant representatives and research leaders concerned with participant involvement in leading genetic research projects and around two recent genetic data controversies: the case of the UK Wellcome Sanger (...) Institute, accused of planning unauthorised commercialisation of African DNA samples, and the case of the company Genuity Science, which planned genetic research on brain tumour samples in Ireland with no explicit patient consent. We advocate for greater specificity in circumscribing the collective to which genetic research relates and for greater efforts in including representatives of this collective as research coleaders in order to enable a more inclusive framing of the good arising from such research. Such community-based participant cogovernance and coleadership in genetic research is vital especially when minorities or vulnerable groups are involved, and it centrally requires community capacity building to help collectives articulate their own notions of the collective good. (shrink)