ABSTRACT
In contrast with the young of most other mammals (except marsupials), human infants are born at an extraordinarily early stage of development. A baby deer can stand and walk within minutes of birth, but a human infant cannot even turn over or crawl until months after birth. At birth, the infant’s skull is not yet fully formed; the myelin sheaths which insulate the neurons in the brain are not yet fully developed; even the visual system in the brain is not yet working properly. Indeed, it has been estimated that human infants really ‘ought’ not to be born until after eighteen months, instead of the actual nine months.
