The child participants were recruited from the nursery and primary schools in
Greater London area in the UK in 2017. Adult participants were recruited from Birkbeck, University of London. Parental consents were obtained for each child participant, as well as consents for adult participants. The final sample for the analyses included 25 4-year-olds, 26 6-year-olds and 24 adults. All participants were tested in a quiet room at school/ in campus. All data were anonymised with a subject reference number. The data consists of reaction time and accuracy measures on a novel computerisd task-switching and modality switching tasks lasting about 15 minutes