The constitution of object permanence is described by Piaget as a milestone in the sensorimotor development. From recently published empirical studies in development psychology it can be concluded that babies with 3,5 months have some insight in the permanence of hidden objects . These findings have not been introduced into the special education theory. This article reviews results from investigations of Spelke, Baillargeon a.o., neuropsychological findings, and the neoconnectionistic approach as an explanation for the lack of seeking behavior of babies up to 18 months. Implications for special education are discussed.