Jean Piaget (1896 – 1980)
Swiss developmental psychologist, famous for his work with children and his theory of cognitive development.
Mixture of assimilation to earlier schemas and adaptation to the actual conditions of the situation is what defines motor intelligence. But — and this is where rules come into existence — as soon as a balance is established between adaptation and assimilation, the course of conduct adopted becomes crystallized and ritualized. New schemas are even established which the child looks for and retains with care, as though they were obligatory or charged with efficacy.
The child who defines a lie as being a "naughty word" knows perfectly well that lying consists in not speaking the truth. He is not, therefore, mistaking one thing for another, he is simply identifying them one with another by what seems to us a quaint extension of the word "lie".