How Does Forgetting Erode Norm Adherence?

Social norms are a pervasive aspect of human life. Previous research has shown that while norm adherence can persist for a long time, it ultimately declines. However, the mechanisms that drive the erosion of norm adherence are not yet understood. Building on a reinforcement learning perspective, the present study (N = 429) examined how forgetting affects norm adherence. Using a diffusion model approach, we examined whether norm forgetting is due to a decline in judgmental bias, perceptual bias, or both. Results showed that norm adherence declined over time but remained reliable for up to 7 days post-acquisition. Diffusion model analyses revealed that norm forgetting was driven by the combination of a rapidly declining perceptual bias and a more gradually declining judgmental bias.