With intellectual development every child passes through numerous stages, roughly matching certain ages. In spite of large individual differences, a definite sequence in stages of development does exist. With the child’s continuously expanding amount of knowledge, its way of thinking is altered so as to reason with thought itself.
During the initial stage – the first two years of life – the child develops from a baby reacting purely out of reflexes to its environment to a toddler reacting with perception and behaving more or less consciously to its environment. In this period the child learns that reflexes are not always sufficient. For example, the infant’s inclination to suck on everything that touches its mouth later becomes more specific as it learns to distinguish different objects.
The next important development is the child’s ability to recognize cause and effect. What first turn out to be accidental discoveries, change into studied action. After the child discovers a couple of times that a toy starts to move by hitting it, later it will act deliberately. The child is becoming active with regards to its environment. By the end of the second year of life an investigating behaviour prevails. Now the child will try something arbitrarily to see the effect (trial and error learning), but gradually the behaviour becomes more purposeful. From the results, the child develops the capacity to execute a simple action in its mind before putting it into practice. The following stages form the preparation in the development of reasoning: after a period during which the child centres all its attention around itself. Follows the period during which it is able to make connections without constantly using itself as a criterion. The child then becomes less egocentric in its reasoning: it learns to think in more categories and to deal with concepts and symbols which again is necessary for learning to read and write.