["Topics in Cognitive Science, EarlyView. ", "\nAbstract\nPsychedelic drugs have shown promise as a novel therapeutic for a variety of health conditions, yet the mechanisms underlying their clinical benefits remain unclear. A leading hypothesis suggests that psychedelics may enhance cognitive flexibility, a trait impaired in many of these conditions. While existing data from self‐report and qualitative‐interview studies support this hypothesis, data from experimental studies are limited and inconsistent. Here, we propose a novel cognitive development model that allows us to more precisely define cognitive flexibility as a mechanism underlying the effects of psychedelics. Considering children—a population known to be more cognitively flexible than adults—as a proxy psychedelic group, we identify three specific behaviors that could be used to empirically test this account: (1) changing the strength of, or reliance on, one's priors; (2) changing one's search and sampling strategies; and/or (3) changing one's allocation of attentional resources. Finally, we highlight preliminary findings from a pilot study supporting this framework and providing guidance for future work.\n"]