How does experienced behaviour change normative expectations regarding socially beneficial actions?

Social norms, understood as shared expectations of appropriate behaviour, can help resolve collective action problems by making salient collectively beneficial equilibria. However, achieving long-lasting behaviour of this type remains challenging, partly because how different social contexts shape individuals’ normative expectations is not well understood. This study uses a controlled laboratory experiment to collect panel data on how individuals’ normative expectations regarding public good (PG) contributions evolve across two sequential social contexts. Using the Krupka and Weber’s (2013) method, we elicited expectations at three points: before a repeated PG game, after it, and after a subsequent PG game in which group members can convey a normative signal through a social exclusion mechanism. Participants first experienced declining contributions in the Baseline PG game, followed by higher contributions when the exclusion mechanism was introduced. After the initial decline, participants’ norm profiles in uncooperative scenarios clustered around lower contributions. Conversely, after experiencing higher contributions under the exclusion mechanism—which provided a cooperative normative signal—normative expectations shifted towards favouring greater contributions. This effect was strongest among participants who initially perceived loose norms. Our findings highlight heterogeneity in how norms are perceived and change, offering experimental evidence on the factors that drive beneficial normative change.