Unpacking Ingroup Source Effects in Politically Polarized Issues: The Interplay of Social Identity, Moral Framing, and Credibility

Although persuasion research increasingly demonstrates that ingroup sources can enhance persuasion outcomes, the underlying processes remain unclear. Drawing on the social identity approach and moral foundations theory, we conducted an online experiment (<i>N</i> = 1,089) with a sample of self-identifying Republicans, examining potential mediators (prototypicality, source credibility) and moderators (source’s leadership status, moral framing) of persuasive effects of ingroup sources advocating action on climate change. Our findings indicate that group prototypicality and credibility serially mediate the effects of ingroup sources on policy support. Additionally, moral framing exhibits an indirect effect on policy support through the same process but does not interact with the source’s group affiliation or the ingroup sources’ leadership status.