ResearchExperimentEvidence: Small study0–24 months
Object permanence in five-month-old infants
Author or publisher Baillargeon, Spelke & Wasserman, Cognition Published 1985 Reviewed by Edustack editors Last checked 13 Nov 2026
1What the study found
Five-month-old babies looked longer when a screen appeared to pass through a hidden box, suggesting they knew the box still existed - months earlier than Piaget's account predicted.
2Source and checks
https://doi.org/10.1016/0010-0277(85)90008-3 Baillargeon, Spelke & Wasserman, Cognition. Object permanence in five-month-old infants. 1985. doi:10.1016/0010-0277(85)90008-3 Link working · 13 Nov 2026 · checked automatically every month