This is the classic practical book on brain development in children and adolescents. One of its main themes is that children mature in different areas at different rates, and that teaching them something before they're ready is fruitless, emotionally risky, and actually damages their later ability to reason naturally.
Supporting reference: Your Child's Growing Mind http://books.google.com/books?id=V1wfk_l2Ch4C
This is the classic practical book on brain development in children and adolescents. One of its main themes is that children mature in different areas at different rates, and that teaching them something before they're ready is fruitless, emotionally risky, and actually damages their later ability to reason naturally.