A signal detection theory meta-analysis of psychological inoculation against misinformation

The spread of harmful misinformation poses a growing global threat, undermining trust in science, public health, and democracy. Psychological inoculation (i.e. "prebunking") offers a promising approach to help people distinguish credible from manipulative content. We re-analyzed 33 inoculation experiments (combined N = 37, 025) using Signal Detection Theory within a hierarchical Bayesian framework. Results show that both gamified and video-based interventions consistently improve discrimination between reliable and unreliable news, without increasing response bias-that is, participants did not become more uniformly skeptical or credulous. Our findings highlight the effectiveness of psychological inoculation in enhancing discrimination while avoiding unintended side effects on trust in credible news, offering robust support for its use as a scalable misinformation intervention.