In order to develop, children with down syndrome need to find an environment that is adequate for them, that is, above all, adequate communication. But they only experience it when we explore together with the children, which makes them significantly more involved in their development and what inhibits them.
With about 150 children, we came to the following conclusions: Since the children do not speak the spoken language during the sensitive phase of speech development from 2 to 6 years due a lack of muscle proprioceptors. They can learn to compensate this deficit in mother tongue lessons with the help of hand gestures from the second year of life and with the help of development orientated reading didactics from the 3rd to 4th year of life. A lower stage of development prepares a higher psychic system, and a higher stage of development may constitute the psychic system of a lower stage of development.
The spoken language is built with the help of gestures and writing. Learning the mother tongue during the sensitive phase of language development is necessary. Because after that time children learn their mother language like a foreign language. The development of proper grammar is the precondition for logical thinking.
The failure of children in mathematics lessons is not a biological fact, but turns out to be a language problem. Learning mathematical operations in childhood is an essential prerequisite for being able to lead an independent life in this culture.