Peekaboo

While not always a fixed rhyme, 'Peekaboo' is one of the oldest games played with infants, helping them understand object permanence (that things still exist when unseen). The term "peek-a-boo" as a children's game dates back to at least the 1590s, with a similar game called "Bo-peep" played since the 1500s. The game plays a crucial role in infant development, as psychologist Jean Piaget noted that young infants genuinely believe objects cease to exist when hidden from view. This simple interactive game helps babies develop memory, language skills, emotional bonds with caregivers, and alleviates separation anxiety by teaching them that people return even after disappearing from sight.