We can “ask” young children what they know by showing them something and seeing if they copy us. One of our early studies showed that infants learn 1-2 brand new things via imitation per day. We can test their memory by delaying when we ask them to copy. This set of studies examines what children of different ages remember and for how long.
Barr, R., & Hayne, H. (2003). It’s not what you know it’s who you know: Older siblings facilitate imitation during infancy. International Journal of Early Years Education, 11, 7-21.
Hayne, H., Barr, R., & Herbert J. (2003). The effect of prior practice on memory reactivation and generalization. Child Development, 74, 1615-1627.
Hayne, H., Boniface, J., & Barr, R. (2000). The development of declarative memory in human infants: Age-related changes in deferred imitation. Behavioral Neuroscience, 114, 77-83. DOI: 10.1037//0735-7044.114.1.77.
Hayne, H., MacDonald, S., & Barr, R. (1997). Developmental changes in the specificity of memory over the second year of life. Infant Behavior and Development, 20, 233-245.
Barr, R., Dowden, A., & Hayne, H. (1996). Developmental changes in deferred imitation by 6- to 24-month-old infants. Infant Behavior and Development, 19, 159-171.