During which stage of cognitive development do children begin to understand object permanence, according to Piaget?

Children begin to understand object permanence during the sensorimotor stage of cognitive development, which lasts from birth to about 2 years of age. Object permanence is the understanding that objects continue to exist even when they cannot be seen, heard, or otherwise sensed.

During this stage, infants learn to coordinate their sensory experiences with motor actions. For example, when a toy is hidden under a blanket, a child who has developed object permanence will understand that the toy still exists, even though it is not visible. This cognitive milestone is significant as it marks the beginning of a more complex understanding of the world, enabling children to engage in more interactive play and problem-solving as they grow.

The understanding of object permanence is a foundational concept in child development, as it indicates the child's ability to form mental representations of objects. This cognitive leap prepares them for more advanced thinking and reasoning stages that follow, such as the preoperational stage, where symbolic thinking emerges, but it is in the sensorimotor stage that the groundwork is laid.