Considerable progress has been made over the past decade towards Millennium Development Goal 4. The number of deaths among children younger than 5 years has declined from 12 million in 1990 to 6·9 million in 2011.1 But do the surviving children have an equal chance to realise their human potential, achieve social justice, and contribute to sustainable development? The global community has an obligation to ensure that all children develop to full capacity, not only as a human right but also for equitable prosperity and sustainable progress of societies.

Three areas are critical foundations for healthy child development: stable, responsive, and nurturing caregiving with opportunities to learn; safe, supportive, physical environments; and appropriate nutrition. These foundations include many familiar best prac- tices: planned, safe pregnancy and childbirth; exclusive breastfeeding in the first 6 months of life with appro- priate complementary feeding and responsive feed- ing; preventive interventions such as vaccines for the treatment of infections and diseases; and protec- tion from toxins, violence, and other environmental hazards.2,3 A stable and engaged family environment in which parents show interest and encourage their child’s development and learning is the most important of these foundations. Such supportive human relationships promote and protect a child’s physical and mental health, behaviour, and learning across his or her lifetime.