Object permanence, as many will remember from college psychology class, refers to the understanding that things and people continue to exist even when you can’t see or hear them. First documented by ...

Fifteen years ago, textbooks on human development stated that babies of six months of age or younger had no sense of "object permanence" -- the psychological term that describes an infant's belief ...

The work of Jean Piaget shaped our understanding of cognitive development in children, and it also gave us several tasks that we can use to study other animals. One classic issue studied by Piaget is ...