How Living in Poverty Affects Children’s Brain Development

Seth Pollak takes a question during his discussion of poverty and childhood brain development.
Seth Pollak takes a question during his discussion of poverty and childhood brain development.

The stress of living in poverty affects children’s brains in ways that are similar to the effects from abuse, an expert on child development said Wednesday at Duke.

“Often children who are abused show high stress levels, but there is an increase and decrease,” said Seth Pollak, a psychology professor at the University of Wisconsin-Madison. “The children in poverty may not reach those high stress levels, but there is a constant stress that never comes down.”

Pollak spoke on the neurobiology of poverty as part of the Sulzberger Distinguished Lecture Series presented by the Duke Center for Child and Family Policy.  He and his colleagues examined 823 brain scans of 431 children from ages 4 to 17 and lived in urban and rural areas.

They found poverty affected brain growth, and the difference can be seen as early as infancy. Infants living in poverty showed a different trajectory of development as early as age 2, suggesting that the longer the child is exposed to an impoverished environment, the greater the difference in brain development.

The brain images of children living in poverty also showed unusually high levels of cortisol -- similar to children who were physically abused. That leads Pollak to believe stressful circumstances might be the common denominator.

“The human brain is very adaptive and humans are a resilient species,” he said. “Impoverished children have less access to medical care, increased exposure to toxins, violence and income inequality. If children had to deal with only one thing, such as poor medical care, we wouldn’t see an effect. Having to deal with all of these factors is more than any one person can deal with. It’s stressful, and subsequently effecting developmental growth.”

The delays in brain growth and development can also affect educational achievement and executive functioning Pollak said.

A delay in the growth of the area of the brain that regulates problem solving, attention and judgment accounted for a 16 percent achievement gap for high schoolers living below the federal poverty line. Likewise, a delay in growth of the area of the brain that monitors memory, emotion and language accounted for a 21 percent difference in academic achievement.

Using neuroscience to understand poverty is a relatively new research method, and Pollak believes this type of research may provide clues to target and refine interventions for youth.

“No one likes the outcomes associated with child poverty,” Pollak said. “This research shows that poverty is not only a social policy issue, but also a biomedical issue.”