The lone dissenter as a non-conformist in the Supreme Court: Extension of past research, cross-cultural analysis and influence model development

Social influence is a potent force in small groups’ decision-making. Asch conducted his foundational lines study demonstrating conformity in such a setting and the difficulty in being a minority of one. His work has been used to assess conformity outside of the lab but may lack applicability to real-world situations. The current study replicates and extends earlier work by analyzing US Supreme Court (SC) jurisprudence (1945 – 2023) and includes Canadian SC voting trends (1953–2023) to investigate conformity cross-culturally. Consistent with past work, we identified unanimous outcomes (9–0) were most prevalent and a lone dissenter (8–1) least in both samples. However, unanimous outcomes were considerably more likely in Canada than in the US. The results are explained based on situational and psychological factors and used to develop a model to examine lone dissenters in small group decision-making. We highlight how the Asch paradigm is not a suitable prism to study SC adjudications and use the new model to suggest future directions for a more robust exploration of social influence in small group decision-making processes.