Differential Development of ‘Hot’ and ‘Cool’ Inhibitory Control from Infancy to Early Childhood

Despite growing research interest in early executive functions, little is known about how these fundamental cognitive skills emerge and develop in the first years of life. A key distinction within the literature separates “hot” (emotionally or motivationally influenced) and “cool” (affectively neutral) executive function skills. However, it remains unclear whether these skills follow similar or distinct developmental trajectories from infancy to early childhood. To fill this knowledge gap, this longitudinal study examined the development of hot and cool inhibitory control (a core executive function) across three time points in infancy and early childhood: 10-months (N = 141), 16-months (N = 75) and 3½ years (N = 93). To track age-related changes whilst minimising bias from differences in task demands, we used scalable or structurally similar inhibitory control tasks across all assessment points. As expected, both hot and cool inhibitory control significantly improved from infancy to early childhood, however the improvement happened earlier for hot inhibitory control. Hot and cool inhibitory control were not significantly associated in infancy, but a hot-cool association emerged by 3½ years. In terms of longitudinal stability, individual differences in hot (but not cool) inhibitory control were stable from 10- to 16-months of age, however neither facet of inhibitory control demonstrated longitudinal associations between infancy and early childhood. Hot IC at 16 months predicted performance on one of the cool IC tasks (Go/No-Go) at 3.5 years, although this result did not survive correction for multiple comparisons so should be replicated in future research. These findings provide new insights into the early developmental trajectories of hot and cool inhibitory control, highlighting both their initial independence in infancy and later convergence at the start of early childhood.