Infancy

Despite being notoriously difficult to study, infants have long been the sine qua non of inquiries into [Page 1131]human development. From Aristotle to Darwin and Freud, infants have been the primary subjects of countless people who have attempted to predict behavior, health, and longevity as well as of attempts to understand the origins of quintessential human experiences such as affection, sensation, and memory. This entry considers infancy as the period from birth to the end of the first year of life and describe of infants’ neurological, physical, cognitive, emotional, social development, as well as their capacity for memory, and their development of a sense of self and others.

The word infant has its origins in the Latin—in “not” + fant “speaking” (from the verb fari)—literally meaning ...