Action initiation and punishment learning differ from childhood to adolescence while reward learning remains stable

Adolescence is often theorized to involve heightened reward learning and impulsivity, but tasks and models that dissociate learning from action initiation are scarce and prior studies have been small. Using computational modelling of a go/no-go learning task in a large multi-country sample of youths (N = 742, 9–18 years), we examined developmental differences in reward and punishment learning and action initiation bias. A model with separate reward and punishment learning rates and a constant action initiation bias best explained behaviour. Punishment learning rates increased with age whereas reward learning rates were stable; in parallel, action initiation biases decreased with age. Results were similar when using pubertal stage instead of chronological age. Findings suggest that apparent adolescent reward responsivity may reflect reduced impulsive action initiation rather than enhanced reward learning.