Two systems, two timelines: Computational evidence for dissociable development in inhibitory control across childhood...

This study examined inhibitory control development across two samples of Chinese children: a cross-sectional (n = 1,122; 45.5% female; 91.9% Han; Mage=12.42 years, range: 6.0-18.7 years) with 6-month longitudinal follow-up and independent validation sample (n = 1,026; 45.1% female; 90.8% Han; Mage=12.44 years, range: 6.1-18.8 years). Generalized additive models applied to Stroop and Go/No-Go tasks revealed four-phase nonlinear developmental trajectories. Response inhibition stabilized by 13.4 years, while interference inhibition developed until 15.8 years. Hierarchical drift diffusion modeling indicated that interference inhibition development was associated with enhanced information accumulation (drift rate), whereas response inhibition development was associated with response bias adjustment (starting point), with shared processing speed improvements-a dissociation emerging across development. These findings support a decision-computational framework for understanding inhibitory control development.