[MarkusQ]

As someone who teaches mathematics (set theory, combinatorics, logic, algebra, etc.) to grade school children, I'd have to say you're way off base. Many first and second grade kids have impressive abstract reasoning skills, though they often lack the vocabulary to express their thoughts. If you want proof, just find an eight year old that's into a complex game (as many of them are) and ask them to discuss the strategy with you.