alonso rocafortCoronel Tarancón, AlbertoDíaz Catalán, CeliaPérez Lagüela, ElenaMartínez Martínez, IgnacioAlonso Rocafort, Víctor2026-03-022026-03-022026Coronel-Tarancón, A., Díaz-Catalán, C., Pérez-Lagüela, E. et al. Epistemic friendship to overcome interdisciplinary barriers and promote sustainability in the UCM 2030 Observatory. Discov Sustain 7, 331 (2026). https://doi.org/10.1007/s43621-026-02592-4https://doi.org/10.1007/s43621-026-02592-4https://hdl.handle.net/20.500.14352/133660Universities are key actors to advance the Sustainable Development Goals (SDGs) in the 2030 Agenda yet interdisciplinary cooperation within higher education remains blocked by persistent barriers and epistemic injustices. This paper analyzes the UCM 2030 Observatory, an institutional initiative within the Complutense University of Madrid (UCM) designed to foster sustainability through interdisciplinary partnership. The study adopted a tiered qualitative design grounded in sustainability science and guided by reflexive, action-oriented principles. Using participant observation, semi-structured interviews, hybrid coding, and participatory validation, it iteratively explored the epistemic, institutional, and affective dimensions of interdisciplinary partnership within the UCM 2030 Observatory. The narrative analysis combined a comparative framework of interdisciplinary barriers with inductively-derived categories, documenting negotiation processes, trust-building, and adaptive mediation. Findings show that interdisciplinarity in universities is sustained not by epistemological synthesis alone but mainly through “epistemic friendship,” an ethos of trust, reciprocity, and horizontality. The study also identifies risks of hierarchical drift and structural disincentives as well as the transformative role of intermediary bodies. Overall, it advances an “affective turn” in interdisciplinarity and offers practical insights for fostering the relational conditions that sustain interdisciplinary research and embed whole-institution approaches in sustainability.engjournal articlehttps://link.springer.com/article/10.1007/s43621-026-02592-4open access3InterdisciplinaritySustainability scienceEpistemic injusticeEpistemic friendship2030 agendaCiencias Sociales5906.01 Derechos Humanos