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object permanence

n. (context psychology English) The understanding (typically developed during early infancy) that an object still exists even when it disappears from sight, or other senses.

Wikipedia
Object permanence

Object permanence is the understanding that objects continue to exist even when they cannot be observed (seen, heard, touched, smelled or sensed in any way). This is a fundamental concept studied in the field of developmental psychology, the subfield of psychology that addresses the development of infants' and children's social and mental capacities. There is not yet scientific consensus on when the understanding of object permanence emerges in human development.

Jean Piaget, the Swiss psychologist who first studied object permanence in infants, argued that object permanence is one of an infant's most important accomplishments, as without this concept, objects would have no separate, permanent existence. In Piaget's theory of cognitive development infants develop this understanding by the end of the " sensorimotor stage," which lasts from birth to about two years of age. Piaget thought that an infant's perception and understanding of the world depended on their motor development, which was required for the infant to link visual, tactile and motor representations of objects. According to this view, it is through touching and handling objects that infants develop object permanence.