Psychologically “wise” interventions can cause lasting improvement in key aspects of people’s lives, but where will they work and where will they not? We consider the psychological affordance of the social context: Does the context in which the intervention is delivered afford the way of thinking offered by the intervention? If not, treatment effects are unlikely to persist. Change requires planting good seeds (a more adaptive perspective) in fertile soil in which that seed can grow (a context with appropriate affordances). We illustrate the role of psychological affordances in diverse problem spaces, including recent large-scale trials of growth-mindset and social-belonging interventions designed specifically to understand heterogeneity across contexts. We highlight how the study of psychological affordances can advance theory about social contexts and inform debates about replicability.