PurposeThe study aims to examine the effectiveness of socially available measures such as concessive messaging, deradicalizing messaging, punishment, and reward in deradicalization, which remains theoretically debatable and empirically unclear and concern social policymakers.Design/methodology/approachThis study surveyed 4,385 Chinese youths in Hong Kong, a special administrative region of China, to clarify the effectiveness.FindingsResults show that receiving concessive messages about radicalism raised radicalism in 2020. Meanwhile, receiving deradicalization messages and rewards reduced radicalism. Receiving punishments for radicalism reduced radicalism when radicalism in 2019 had been high.Originality/valueThese results support social learning theory and imply its usefulness for deradicalization. That is, deradicalization can rely on messaging countering as opposed to conceding to radicalism and reinforcement for deradicalization and against radicalism.