This research examines the early emergence of source-monitoring abilities. Previous research has consistently demonstrated that children as young as 3 to 4 years of age do well on simple versions of action-based source-monitoring tasks. Research on even younger children, however, remains lacking. In this study we examined whether 2 1/2-year-olds…

In simple rule-switching tests, 3- and 4-year-olds can follow each of two sorting rules but sometimes make perseverative errors when switching. Older children make few errors but respond slowly when switching. These age-related changes might reflect the maturation of executive functions (e.g., inhibition). However, they might also reflect…