A nurse assessing a 10-month-old infant watches the infant cry when the parents leave the room. Which developmental concept does the infant possess?

Choice A rationale Stranger danger, or stranger anxiety, is the distress an infant experiences when approached by an unfamiliar person, which typically emerges around 6 to 9 months of age. While related to cognitive development and attachment, this concept does not explain the specific behavior of crying when parents leave the room, which indicates the child knows the parent still exists even when unseen. Choice B rationale Assimilation is a cognitive process, described by Piaget, where a child incorporates new experiences into existing schemas (ways of thinking). This concept relates to how a child learns about the world. It does not directly explain the emotional reaction of crying when a primary caregiver leaves, which is a specific emotional milestone linked to the awareness of object permanence. Choice C rationale The infant possesses the developmental concept of object permanence, which is the understanding that objects, including parents, continue to exist even when they cannot be seen, heard, or touched. This cognitive milestone, typically achieved between 8 and 12 months, causes distress (separation anxiety) when the parent leaves because the infant knows the parent is still somewhere but is not with them. Choice D rationale Fixation is a concept in psychosexual development, theorized by Freud, referring to an unresolved conflict or strong attachment to an earlier stage of development. This concept is not relevant to explaining the normal, expected emotional reaction of an infant to a parent leaving the room, which is a typical manifestation of separation anxiety resulting from object permanence acquisition.