does early intellectual endeavor breed materialists?

"Children that we train intellectually before the age of four or five take something really terrible into later life: we bring them up to be materialists. The more you raise a child intellectually before the age of four or five, the more you create a materialist in later life. The brain develops so that the spirit lives within its form, but inwardly people have an intuition that everything is only material, because the brain has been taken over by intellectualism at such an early age." -Rudolf Steiner