The authors set out with a laudable object of tracing a child's development chronologically, in order to give a sense of continuity, and to discuss various aspects of growth, physical, intellectual, social and emotional, at each age period, so as not to consider them as unrelated phenomena. They attempt to integrate data on child development with general behaviour theories, notably those of Piaget. They try to say why the child is what he is, and why he behaves in a particular way.