Advocacy practitioners are carriers of particular skills, dispositions and practical know-how that are gained through their prior professional and cultural experiences. When practitioners are recruited to an advocacy NGO, these attributes contribute to the organisation’s epistemic culture. Drawing on original data, this chapter studies the occupational, educational and cultural backgrounds of full-time practitioners working at Amnesty International, Human Rights Watch and the International Crisis Group. The humanist and liberal-cosmopolitan working cultures of these organisations are found to be highly socially bounded due to their narrow recruitment streams that target Western-educated elites. Furthermore, practitioners and board members’ prior employment at institutions that are the primary audiences of humanist advocacy, such as the United Nations, liberal media outlets and Western policy circles, reinforces the strong affinity between the producers and consumers of knowledge. This homology raises questions over the extent to which advocates can challenge existing political orthodoxies.