​Can moral language mobilise political supporters into action?

​While political parties remain central to democratic life, activism among party supporters has been in long-term decline. At the same time, far-right populist parties have gained ground across Europe. This talk asks a pressing question for mainstream parties and advocacy organisations alike: how can sympathisers be mobilised into meaningful action?

​Drawing on social and moral psychology, this research examines whether appeals to shared ethical values can spur costly forms of political engagement such as donating money or volunteering. In a large randomised field experiment conducted with an Austrian political party, around 20,000 newsletter subscribers received either morally framed messages, pragmatically framed messages, or no message at all. While all messages defended the party’s policies and criticised populist competitors, only the moral appeals grounded in values like justice, inclusion, and diversity increased real-world donations. Pragmatic appeals to efficiency or feasibility had no measurable effect.

​The findings suggest that moral language can play a powerful role in mobilising supporters, offering practical lessons for parties competing in an increasingly polarised political environment.

​About the speaker
Francisco (Paco) Tomas-Valiente is a PhD researcher at ETH Zürich and a visiting researcher at the London School of Economics until June 2026. His work partners directly with political parties and civic organisations to study how they mobilise supporters, grow their base, and counter far-right challengers. He has also researched get-out-the-vote campaigns and collaborated on experiments to improve the quality of online political discourse. Party and advocacy practitioners interested in running experimental interventions on donations, volunteering, or candidacy are warmly encouraged to get in touch.