Designing social tipping interventions: an actionable framework for scaling up behavioural change

Social tipping, the process by which a new behaviour spreads rapidly upon reaching a critical mass, offers a promising pathway for large-scale behavioural change. However, systematically designing interventions to trigger social tipping dynamics remains a key challenge. This paper is a framework contribution: it synthesises existing theoretical and empirical insights on threshold models and social tipping, and proposes an actionable two-phase procedure for intervention design. The first phase involves assessing the potential for social tipping by evaluating the prevalence of the target behaviour and the underlying preferences and social expectations that sustain it. We propose a method for eliciting individual thresholds for changing behaviour, distinguishing between conditional individuals (those whose adoption decisions are influenced by others' behaviour) and unconditional individuals (those who are independent of others' decisions). The second phase uses the diagnostic findings to inform strategic decisions about whom to target and how to intervene to activate the social tipping process. We analyse the trade-offs between targeting different subpopulations (e.g., amenable vs. resistant individuals) and propose a ``stepping stone'' approach that breaks down change into manageable steps, which can be particularly effective in populations with polarized individual thresholds. Taken together, our framework offers to researchers and policymakers a roadmap for scaling up large-scale behavioural change through social tipping.