> One of the most enduring ideas in educational psychology is the stage-based theory of Jean Piaget[0]. Computer use belongs very much in 'formal operations', the last stage of the theory, because everything that happens in the computer is just an abstract representation of what happens in the physical world. Progress between stages varies from child to child, but from Piaget's observations, it usually happens around the age of 11, which is when children transition from primary school to secondary school in the Australian and British school systems. This is why children struggle to learn, say, algebra, in primary school. If you introduce these ideas before children are ready for them, they internalise them as social rules in the same way as 'raise your hand before speaking in the classroom'. So not only does introducing computing too early harm the development of other skills, it also teaches a suboptimal approach to computing.

Bear in mind approximately none of his claims have been experimentally validated, and my experience (and I suspect that of many other HN users) is the opposite.