The ‘Introduction’ looks at recent developments in child psychology such as new techniques in brain imaging and genetics, and research into cognitive development and social/emotional development. The latter is intrinsically linked to cognitive growth. A key factor for infant development is the quality and quantity of language to which the child is exposed to. A child is an active learner. If children witness early learning environments at home and away from the home that are stable, responsively contingent and linguistically rich, then the brain will have the best opportunity for optimal development.