The science on understanding or remembering
The developmental psychologist Jean Piaget suggested that very young babies don’t understand that objects stay the same, and still exist when they can’t see them. He argued that this understanding develops as babies had more experience of objects, and described this knowledge as object permanence.[1]
Other scientists disagree and think that babies do have this understanding of objects from birth, and that what develops is their ability to remember something they can’t see.[1,2] So, very young babies know things still exist, they simply forget that they were playing with them!
Your baby will begin to remember and search for what’s gone
Based on the research that has been carried out so far, when your baby was younger, they may have assumed if someone had left the room or the house, that they no longer existed, or if a toy is missing, it had gone forever.
Now though, if your baby can’t see a toy that is just out of sight, they will remember what they were playing with and be willing to have a look behind, or to the side, and find it.
More research will be needed to find out just how babies think of or remember objects. Your baby is either remembering things for longer or developing their understanding of objects and existence – either way, this is an important step!
How you can help them to recall
When you talk about where the toy is, ask questions about its location, such as “Is it behind you? Is it on this side? Is it under here?” This way, you’re teaching your baby about the possibilities and encouraging them to explore.
Your baby is learning to hold things in mind, to know that something they recently had must be here somewhere... a feeling that we are all very familiar with in our daily lives – two words: house keys!
References
[1] Baillargeon, R. and DeVos, J., 1991. Object Permanence in Young Infants: Further Evidence. Child Development, 62(6), pp.1227-46.
[2] Baillargeon R. (2008). Innate Ideas Revisited: For a Principle of Persistence in Infants' Physical Reasoning. Perspectives on psychological science: a journal of the Association for Psychological Science, 3(1), 2–13. https://doi.org/10.1111/j.1745-6916.2008.00056.x
[3] Addyman, C. (2020) The laughing baby: The extraordinary science behind what makes babies happy. London: Unbound.