ABSTRACT
All living things adapt to their environments by use of the complementary processes. Why, asks Jean Piaget, should the functioning of the mind be governed by different principles? In cognitive development, however, it is not foodstuffs that are being assimilated; it is the reality of the world. The process is constant throughout development, but the product is an ever-changing body of knowledge which step by step comes into balance with the realities of the environment. And why do children under seven months of age develop their distinctive posthospitalization preoccupation with the environment? Babies as young as this are unable to stand, are often confined in solid-sided cribs, are rarely picked up—hence their hospital environment is perceptually dull, even static. Piaget says that incoming stimulation from the environment may at first do no more than "feed" those reflex actions which are built in by heredity.
