Current intellectual calls for more socially minded governance often resort to the authority of the experimental and behavioral economists who have provided uncontroversial evidence for the generalized existence of a Homo socialis. For a qualitative social researcher, the narrative of a “discovery” makes little sense. This article provides a more meaningful account of the experimental rationale of prosocial preferences research, interrogating, from a “decolonial” theoretical perspective, the epistemic and normative implications of a method that persuasively claims to have challenged the (...) intellectual imperialism of Homo economicus. Just as the colonial discourse that speaks of the “discovery” of America has shaped the global Eurocentric mentality that splits the world into hierarchical binaries, the academic discourse that speaks of the “discovery” of Homo socialis could reinforce a behavioral range that reduces the interpretation of non-prosocial choices to a binary spectrum still metrologically organized around Homo economicus. The danger is that Southern subjects do not always have the privilege of feeling prosocial and could be penalized for their disadvantage within a socially minded mode of governance. To address this danger, the article argues, experimental social scientists need to become qualitatively attuned to the methodological question of “range validity” beyond the traditional one of “external validity.”. (shrink)