Das sensumotorische Stadium ist charakterisiert durch ein "Hier-und-Jetzt"-Verständnis der Welt, extreme Egozentrik, Abwesenheit der Sprache und die Erweiterung von Schemata.

In the beginning, a child’s understanding of the world depends on their direct experience of perceptions and objects. Actions discovered first by accident are repeated and applied to new situations to obtain the same results. Toward the end of the sensorimotor stage, the ability to form primitive mental images develops as the infant acquires ‘object permanence’. Until then, children have no idea that objects can exist apart from themselves.