The child during the first seven years is really completely and wholly an eye. Now consider only this thought: in the eye a picture is formed, an inverted picture, of every external object. This is what ordinary Physics teaches everyone. That which is outside in the world is to be found within the eye as a picture. Physics stops here, but this picture-forming process is really only the beginning of what one should know concerning the eye; it is the most external physical fact.
But if the physicist would look upon this picture with a finer sense of observation, then he would see that it determines the course of the circulation of the blood in the choroid. The whole choroid is conditioned in its blood circulation by the nature of this picture within the eye. The whole eye adjusts itself according to these things. These are the finer processes that are not taken into consideration by our ordinary Physics. But the child during the first seven years is really an eye. If something takes place in the child’s environment, let us say, to take an extreme example, a fit of temper when someone becomes furiously angry, then the whole child will have a picture within him of this outburst of rage. The etheric body makes a picture of it. From it something passes over into the entire circulation of the blood and the metabolic system, something which is related to this outburst of anger.
This is so in the first seven years, and according to this the organism adjusts itself. Naturally these are not crude happenings, they are delicate processes. But if a child grows up in the proximity of an angry father or a hot-tempered teacher, then the vascular system, the blood vessels, will follow the line of the anger. The results of this implanted tendency in the early years will then remain through the whole of the rest of life.
These are the things that matter most for the young child. What you say to him, what you teach him, does not yet make any impression, except in so far as he imitates what you say in his own speech. But it is what you are that matters; if you are good this goodness will appear in your gestures, and if you are evil or bad-tempered this also will appear in your gestures — in short, everything that you do yourself passes over into the child and pursues its way within him. This is the essential point. The child is wholly sense-organ, and reacts to all the impressions aroused in him by the people around him. Therefore the essential thing is not to imagine that the child can learn what is good or bad, that he can learn this or that, but to know that everything that is done in his presence is transformed in his childish organism into spirit, soul and body. Health for the whole of life depends on how one conducts oneself in the presence of the child. The inclinations which he develops depend on how one behaves in his presence.
Source: Rudolf Steiner – GA 311 – The Kingdom of Childhood – Lecture 2 – Torquai, 13th August 1924