Rational action selection in 1½- to 3-year-olds following an extended training experience

Previous studies failed to find evidence for rational action selection in children under 2 years of age. The current study investigated whether younger children required more training to encode the relevant causal relationships. Children between 1½ and 3 years of age were trained over two sessions to perform actions on a touch-sensitive screen to obtain video clips as outcomes. Subsequently, a visual habituation procedure was employed to devalue one of the training outcomes. As in previous studies, 2- and 3-year-olds chose actions associated with an expected valued outcome significantly more often during a subsequent choice test. Moreover, analysis of children’s first responses in the post-devaluation test revealed evidence of rational action selection even in the youngest age group (18–23 months). Consistent with dual-process accounts of action control, the findings support the view that the ability to make rational action choices develops gradually.

► Children >2 years select actions rationally to obtain currently desirable outcomes.
► Younger children tend to chose actions regardless of expected outcome’s desirability.
► We found evidence of rational action selection <2 years after extended training.
► Results support dual-process models of action selection and initiation.