One in five children in America live in poverty. In Suffolk County, which includes Boston, Revere, Chelsea, and Winthrop, the rate of childhood poverty is even worse. That's according to census data highlighted in a recent report by The Robert Wood Johnson Foundation.

If you ask Amanda Currin, a mother of three on welfare, what poverty looks like, she'll tell you it depends on where you're looking.

Click the county to see its percentage of children in poverty

"Different countries, you think of little kids on TV eating oatmeal or rice out of a bowl, you know, dirty, no clothes," Currin said. "But here, it's this. It's me, it's every other family that I know from South Boston."

Amanda lives with her husband, children and two cats in subsidized housing in Dorchester. She and her husband both grew up poor.

"It's having to use food stamps to get food or else you wouldn't have anything," Currin said. "It's being on WIC because you can't afford milk, and living off welfare, worrying about how you're going to pay for school, racking up a bunch of debt. It's kind of just what I'm living."

Amanda and her family are part of the growing number of poor in Suffolk County. It’s one of the most racially diverse counties in America, but it’s also a county where one in three children live in poverty. That's 10 percent above the national average.

The impact of poverty on health and life outcomes is well known. Children who grow up poor are more likely to suffer from diabetes and obesity. They’re less likely to graduate high school and more likely to engage in risky sexual behavior as teens.

But pediatrician Jack Shonkoff said what’s not well known is that poverty can actually affect a child’s biology.

"In the last 20, even in the last ten years, there have been advances in neuroscience and molecular biology and genetics that have really given us a much deeper understanding of how the adversity of poverty gets under the skin and into the body," Shonkoff said. "How it literally affects the development of the brain's architecture."

Shonkoff directs the Center on the Developing Child at Harvard University. He says that the negative effects of poverty start at birth.

"The brain at birth has most of the cells it’s going to have - most of the neurons - but very little of the circuits, and those circuits are built over time," he said. "How the circuit gets built is heavily influenced by experience."

Life experience literally shapes the circuitry of the brain. That's why the stress of poverty is particularly harmful for babies and young children.

"This level of adversity and stress actually activates the stress response in children and the stress response system is made to deal with an acute threat," Shonkoff said. "It's not meant to be chronically activated, and when it's chronically activated, it can have a wear-and-tear effect on the body. It can literally disrupt the development of circuits in the brain."

When development is disrupted, it becomes more difficult for a child to learn some essential coping skills.

"These are things like the ability to focus your attention, the ability to control your impulses, to plan, to monitor, to solve problems, to follow directions," Shonkoff said. "And young children learn these skills from adults who have these skills. Many adults who grow up in poverty never develop these skills well in the beginning."

These skills can be learned later in life, though just like a new language, they are harder to pick up as you age. Still, Shonkoff said its essential parents learn these skills so that they can teach them to their children.

"If we want to prevent young children from ending up living in poverty, if we want to change their lives, we have to change the lives of the adults who are raising them," he said. "We can't bypass those adults, and we can't just stigmatize them and demonize them and say that they are just not doing a good job, because, for the most part, they were once children who were raised in poverty."

As for the Currins, they are doing what they can to buffer their children from the stress of poverty. Robert Currin talks to a counselor regularly.

"He helps me kind of organize my thoughts a little bit and think things through a little bit more," he said. "I get a little angry sometimes, and I get really bad anxiety so just talking to him about some of that stuff just helps out."

Amanda also talks to a counselor, and all three of their children are in Head Start, an early education program for children in poverty. Amanda said the structure and predictability of the program has really helped her kids, and they eat breakfast and lunch there, too.

"I feel like it could be worse, we could be alone, we could be into drugs and alcohol, we could be crappy parents, but we are kind of ahead of the game, except in the game of being broke," she said. "We have focus. We know what we want and we’re going to work hard to get there, and a lot of people I’ve met don’t have that. They don’t have that drive."