Nothing is as central to the field of child development as the notion of stages. With respect to motor, cognitive, language, perceptual, and moral development, highly influential theories have been proposed in which children are seen as developing towards maturity by passing through a series of stages. While it might be quite easy to accept the idea of a natural sequence of stages that children pass through in learning to walk or talk, there is no really compelling reason to expect the same to be true of learning to read. After all, reading is a product of cultural evolution rather than a biologically evolved skill like walking or talking; it depends on cultural transmission for its continued existence.