Steven, aged 10 months, picks up two blocks, bangs them together and puts one in his mouth. As these authors tell us: “He was listening to the sound they made or feeling the shape with his tongue.”

Only four months later he’s made a quantum leap, and is pushing one of the blocks along the floor making a “brumming” sound. “Using a piece of wood in place of a motor vehicle is an example of inference.”

A book such as this is fascinating for all sorts of reasons. We’ve all marvelled at the speed at which young children develop. We want explanations, and here we have them authoritatively presented. The latest research is channelled into good advice: “Does (a two-year-old boy) need a lot of toys? No... he needs room to stretch his powers of imagination. And he can do this best with simple objects that he finds around him.” An excellent book, by authors who understand the subject and know about real children.