The Promise and the Peril of Early Childhood Brain Development

In a recent article in The New York Times, Nicholas Kristof reported on a landmark policy statement just issued by the American Academy of Pediatrics, the leading association of American pediatricians. Based on several decades of scientific research, the Academy has identified “toxic stress” as the most widespread peril facing young children.

What does this mean?

As the Academy explains, toxic stress arises from hostile, chaotic, and uncertain environments. When it occurs early in childhood, this type of stress bathes the developing brain in dangerous hormones that disrupt the body’s metabolism and threaten the architecture of the brain. The brain is most sensitive to these harmful effects during the period from conception through early childhood.

Exposure to high levels of toxic stress early in childhood has been shown to result in a range of poor physical, social, emotional and cognitive outcomes. As adults, individuals exposed to high levels of stress early in childhood are more likely to suffer heart disease, obesity, diabetes and other physical ailments. They are also more likely to struggle in school, have short tempers, and tangle with the law.

Unfortunately for Memphis, many of the factors that make for hostile environments early in childhood are closely associated with growing up in poverty. According to Jack P. Shonkoff, a Harvard pediatrician and leading researcher in this area, this connection helps to explain why kids who have experienced social and economic disadvantage in early childhood often have more trouble learning.

How much does early childhood poverty matter?

University of California researcher Greg J. Duncan and his colleagues have devised a series of studies to measure the effect of poverty at different points in childhood. Their findings are striking. Compared with individuals who grew up in middle-class families, Americans who spent their early childhoods in poverty are likely to experience markedly different pathways through life. Some of the most striking differences only become evident when these children grow up. As a group, children who spent their first five years in poverty will stop school two years earlier, will earn less than half as much, will receive more welfare assistance and have triple the risk of being in poor health.

These findings are a wake-up call for Memphis and Shelby County, where more than half of all children born each year start life in families living in poverty (with incomes below $23,000 for a family of four). Even more troubling, more than half of young children in Memphis living in poverty are in families living on incomes closer to half that amount. These children will grow up with fewer books and games, they will hear fewer words, and are likely to be uprooted much more frequently. By the time they arrive at kindergarten, this group will have kindergarten readiness, and social emotional development scores far behind their middle-income peers.

So where is the good news?

Just as early childhood is a vital developmental period, so too is this the most cost-effective window to bring about change, not only for individuals, but also for entire communities. In the words of the Academy:


In the year ahead, our own policy work will increasingly focus on aspects of an early childhood investment strategy for Memphis and Shelby County and its implications for educational achievement, economic productivity, criminality, and health disparities.