Amid recent progress in cognitive development research, high-quality data resources are accumulating, and data sharing and secondary data analysis are becoming increasingly valuable tools. Integrative data analysis (IDA) is an exciting analytical framework that can enhance secondary data analysis in powerful ways. IDA pools item-level data across…

Young children tend to expect that 2 members of the same category will share properties, yet they frequently deny that an individual's properties will remain stable across time and context. Two experiments, involving 72 four- to five-year-olds, 72 seven- to eight-year-olds, and 76 undergraduates, explored the factors that lead children to…

This study investigated the development of the understanding of class inclusion in children age 5, 7, and 9 years, whose performance on a qualitative class-inference task assessing their appreciation of the transitive and asymmetrical nature of inclusive relations within the animal domain was compared with their ability to make quantitative…