Which concept do children begin to understand during the sensorimotor stage according to Piaget?

During the sensorimotor stage of cognitive development, which occurs from birth to approximately two years of age, children begin to understand the concept of object permanence. This idea signifies that objects continue to exist even when they cannot be seen or heard. For example, when a toy is hidden under a blanket, children in this stage learn that the toy is still there, despite being out of sight. This realization marks a critical development in the child’s understanding of the world and reflects their ability to form mental representations of objects.

As children explore their environment through their senses and motor activities, they develop this important concept. Mastery of object permanence is fundamental to later cognitive milestones, such as problem-solving and the ability to engage in symbolic play. The other concepts listed, such as conservation of mass, reversibility, and abstract thinking, are associated with later stages of development, specifically the concrete operational and formal operational stages, where children develop more complex logical thinking abilities.