This paper discusses alternatives to the nativist claim that domain-specific knowledge is hardwired in the human genome and to the empiricist claim that the human mind is an equipotential general problem solver. In contrast to these views, the paper presents an emergentist-constructivist view of the mind/brain and argues that development itself is the clue to understanding the human representational system. Using certain connectionist perspectives the paper argues that the interaction between, on the one hand, computational, architectural and timing constraints and, on the other, domain-specific structures of environmental input, can explain how domain-specific specialisation of the brain emerges from the developmental process itself. The second part of the paper goes beyond infancy and addresses the issue of flexibility and how representational change also emerges from developmental processes. It presents two brief examples—one from spatial cognition, the other from language—to argue that the child's brain undergoes a process of representational redescription whereby knowledge that is in the cognitive system becomes knowledge to the cognitive system, thereby making possible flexibility and creativity.