The effort should be made when a child is first sent to school to
determine just how much work he can do comfortably and happily. If an
attempt is made to force him to do more than this, he will become
depressed and worried. With children, any mental worry will shortly
produce unmistakable signs on the physique. It is a bad plan to attempt
to get as much as possible out of a child; there should always be a
certain amount of vital energy left for emergencies.