Putting science into practice for early child development

The debate between nature and nurture as determinants of early child development is over. Today, we understand that the two are inextricably linked. The degree of their interdependence—and the impact of this interplay on the developing brains of children—is even greater than we previously imagined.This knowledge has tremendous implications for how we design and deliver early child development interventions.

During the past 24 years, the united efforts and shared goals of the global community have achieved substantial progress in child survival, and child mortality worldwide has declined by 49%.We can build on those gains by focusing new effort and attention not only on saving children's lives, but also on supporting the healthy development of their brains. This is especially important for the millions of children growing up in the most disadvantaged and vulnerable communities and countries, who already face multiple adversities and whose societies also suffer the consequences of those deprivations.

We already know that the brain develops most rapidly in the first few years of a child's life. During these critical years, neuroplasticity is at a peak—neurons form new connections at the astounding rate of up to 1000 per second.
These synaptic connections are the foundation of a child's physical and mental health, affecting everything from longevity to the lifelong capacity to learn, from the ability to adapt to change to the capacity for resilience.

New lines of research are expanding our understanding of the part environment plays in the formation of these neural connections. If children fail to get what they need—enough nutrition, nurturing, stimulation, and a sense of security—during the most critical years of early childhood, the impact on their lives and futures is enormous. For example, inadequate nutrition in the early years of childhood can result in stunting, which can cause diminished physical and cognitive development that undermine a child's ability to learn and earn later in life. Similarly, inadequate stimulation during the same critical period of earliest childhood can reduce learning capacity and ability to form social and emotional attachments.

The impact of such deprivations can intensify in situations that produce toxic stress in children, including chronic deprivation and prolonged hunger, domestic violence and abuse, and the effects of living through violent conflicts and other catastrophes. Toxic stress increases the production of cortisol, a hormone that can disrupt the healthy development of the brain, affecting health, learning, and behaviour. Toxic stress also undermines the ability of the body to absorb nutrients, so potentially exacerbating malnutrition.