Five-year-old Naja Tunney’s home is filled with books. Sometimes she will pull them from a bookshelf to read during meals. At bedtime, Naja reads to her 2-year-old sister, Hannah.

“We have books anywhere you sit in the living room,” said their mother, Cheryl Tunney, who curls up with her girls on an oversized green chair to read stories.

Naja and Hannah are beneficiaries of Reach Out and Read, an early intervention literacy program that collaborates with medical care providers to provide free books when families come in for check-ups.

“I learn things that my brain will always know,” Naja said during an appointment at Group Health Cooperative’s Capitol Clinic in Madison.

Naja’s and Hannah’s brains are in critical phases of development, and they are being stimulated by a home environment that prioritizes education.

Coburn Dukehart / Wisconsin Center for Investigative Journalism

But children who do not have this same experience early in life — especially those growing up in poverty — could experience delayed brain development that significantly harms their educational progress, according to recent research by psychology professor Seth Pollak and economist Barbara Wolfe at the University of Wisconsin-Madison.

Their study is part of a growing body of socioeconomic brain research documenting what Joan Luby, a child psychiatry professor at Washington University in St. Louis, calls “poverty’s most insidious damage” — that poor children are up against their own biological development.

Along with graduate students Nicole Hair and Jamie Hanson, Pollak and Wolfe found that poverty can cause structural changes in areas of the brain associated with school readiness skills.

These parts of the brain are susceptible to circumstances often present in poor households, including stress, unstable housing, nutritional deficiencies, low academic stimulation and irregular access to health care.

To isolate the effects of poverty from other factors, the study included mostly children of educated mothers — 85 percent reported at least some college-level education and 22 percent had some graduate-level education. Families with factors that could negatively affect brain development, such as a risky pregnancy or a history of psychiatric problems, were excluded.

Coburn Dukehart / Wisconsin Center for Investigative Journalism

The study examined brain development of 389 mostly white young people ages 4 to 22 with educated mothers. Household income ranged from less than $5,000 to between $100,000 and $150,000. The fathers had similar educational backgrounds.

The findings suggest that while schools have been the focus of reforms aimed at closing Wisconsin’s long-standing racial and economic achievement gaps, efforts perhaps should start much earlier and be directed at raising income levels of poor children.

An estimated 28 percent of the state’s children live below 150 percent of the federal poverty level. Pollak found that income bracket — which for a family of four is $36,450 a year or less — was associated with diminished brain development and learning.

In a 2016 policy statement, the American Academy of Pediatrics calls the amount of child poverty in the United States “unacceptable and detrimental to the health and well-being of children.”

Legislators on both sides of the aisle in Wisconsin are beginning to agree that more needs to be done to help children.

Pollak’s study found that as much as 20 percent of the gap in test scores of low-income children is explained by developmental lags in the frontal and temporal lobes — critical areas of the brain responsible for learning, including attention, emotion regulation, processing complex ideas, memory and comprehension. Children below 1.5 times the federal poverty level scored four to eight points lower on two standardized tests than children who were not poor.

Courtesy of Jamie Hanson/Carolina Consortium on Human Development, Duke University

These tests are the Wechsler Abbreviated Scale of Intelligence and the Woodcock-Johnson III Tests of Achievement. On both tests, a composite score between 90 and 110 is considered average.

Researchers also found that children from these poor households have less gray matter — 3 to 4 percent below developmental norms for their sex and age. A larger gap of 7 to 10 percent was found in children living below the federal poverty level, $24,300 for a family of four.

“This is suggesting that there is something about a child’s early environment that is affecting the way their neural systems are working that undermine their ability to extract information and succeed in school,” said Pollak, who is also the director of UW-Madison’s Child Emotion Lab.

Other research has shown a connection between early childhood trauma and “toxic stress” on the ability of children to learn.

Gaps big in Wisconsin

Wisconsin has the largest disparity in the country between the performance of black and white students and the rate at which they graduate. The state also has the highest suspension rates for black high school students in the nation, the Wisconsin Center for Investigative Journalism’s Children Left Behind series reported in December. Despite various local and state efforts, the pattern has not changed much over 20 years.

Wisconsin also has the second-largest poverty gap in the United States between blacks and whites, a disparity that has grown faster than the national average, according to a December report from the UW-Madison Applied Population Lab.

Pollak’s study shows poverty can have biological effects long before children enter the classroom, strengthening the case that efforts to close the achievement gap should begin prior to a child’s first day of school. Given the findings, it is “not really a surprise,” Pollak said, that children from low-income families are doing so poorly.

In 2013, in an earlier study, a team led by Wolfe and Pollak examined how family poverty can affect the rate of brain growth among young children.

They found that infants from lower-income families started life with a similar amount of gray matter to infants whose families were not poor. But by their toddler years, poor children had less total gray matter, they found.

Smaller volumes of brain tissue also were tied to greater behavioral problems in the preschool years, the 2013 study found. The effects of poverty on brain size were strongest among the most impoverished children.

Courtesy of Jamie Hanson/Carolina Consortium on Human Development, Duke University

“As infants aged — and presumably had increased exposure to the effects of their environments — the differences in brain volume between poor children and those with greater resources widened,” according to the study.

These studies provide a biomedical explanation for why poor children tend to do worse in school.

“It is the delay of brain development that is accounting for the significant achievement test scores in children living in poverty,” Pollak said. “Now we know that that achievement gap in poverty is at least partially explained by slower brain growth attributed to poverty.”

The effects of poverty on the brain were concentrated among children from the poorest households, those below 150 percent of the federal poverty level. There was no difference between lower-middle-class children and those from affluent families.

“It’s not like we need to get everybody up to affluence,” Pollak said, “we just need to have kids not living in scarcity.”

Stress adds to school woes

While researchers now can point to poverty as a cause of developmental brain delays, they do not know what specifically about poverty is changing children’s brains. Pollak theorized it could be the “pervading sense of stress” that can accompany poverty.

The prolonged activation of stress response systems, known as toxic stress, in a child without the buffer of a stable environment can disrupt brain development and cause other harmful consequences such as increased risk for disease into adulthood, he said.

Bridgit Bowden / Wisconsin Public Radio

“It’s that whole atmosphere that is contributing to the way kids sleep, to the stress level, or the regulation level of the way they digest food and the way that they grow,” Pollak said. “And that whole environment taken together, that it is poverty, and that’s what is actually affecting central nervous system development.”

So-called adverse childhood experiences can rewire a child’s brain in a way that makes it harder to learn, Dr. Bruce Perry told a group of Wisconsin juvenile court and child welfare officials meeting in Wisconsin Dells last fall.

Perry, professor of psychiatry and behavioral sciences at Northwestern University, emphasized that not all stress is bad.

“Stress is what helps you develop. Stress makes you a better musician. Stress makes you a better athlete,” Perry said. “Stress makes you better. It is the pattern of stress that makes all the difference.”

He explained that if the stress is “moderate” and “controllable,” children can develop successful mechanisms for responding to future, unexpected stresses. But other kinds of stress caused by factors such as violence or neglect in the home can create a state of alarm that makes children more reactive, often described as the fight, flight or freeze response.

When presented with new material in school, for example, such children may have a hard time activating the thinking part of the brain.

“If you are a child who is dysregulated, and you are introduced to the very same challenge that the rest of the class is, you are so overwhelmed that you shut down your cortex completely and your cortex is unable to actually process information,” Perry said.

“And in order to master the same content, you are required to have 10 times the repetition, which is not going to be provided in the typical classroom environment, and you’re going to fall further behind.”

Parent, child brains linked

Not only are children’s brains more malleable in early childhood, the brains of new parents are also subject to change, according to a June 2015 study from the Aspen Institute, an education and policy studies nonprofit organization based in Washington, D.C.

New mothers and fathers experienced structural changes during the first few months after their children’s birth, according to the report, as their newborns’ brains are also developing — emphasizing a need for a two-generation approach to early intervention.

Coburn Dukehart / Wisconsin Center for Investigative Journalism

“True two-generation interventions don’t say … the parent is just a route to making the child’s life better,” said Dipesh Navsaria, a UW-Madison associate professor of pediatrics, who was not involved in the study. “The parent and the child both have inherent value, and we should be investing in them both because … that’s where we get an added effect.”

Pollak explained that human brains develop structurally in an inside-out pattern. The frontal lobe behind the forehead controls behavior and attention — skills children need in school — and it develops later.

“Because those parts of the brain are very late developing, they might be very vulnerable … because they’re growing a lot while children are encountering or not encountering things in the world,” Pollak said.

Children’s brains are in a constant state of growth, or plasticity, and they can tolerate a number of adverse experiences before long-term effects are seen, Pollak said. That resiliency means some effects can be reversed.

“It’s just a question of what’s the cost of waiting longer and longer before we do something,” Pollak said.

As Navsaria explained, it is more difficult to address a speech delay in an 8-year-old than a 3-year-old, and in a 3-year-old than an 18-month-old.

“The upshot of this is that you have this fantastic opportunity in the first five years of life to wire things right, or if they’re not wired right, to do remediation,” Navsaria said. “If we get it right early on, then we have a better likelihood of a good outcome.”

Reading gateway to learning

Navsaria is also the medical director of the Wisconsin branch of the national Reach Out and Read program, which was examined as part of an October 2015 Aspen Institute report. There are about 160 Reach Out and Read programs and 50 clinics in training in Wisconsin.

Coburn Dukehart / Wisconsin Center for Investigative Journalism

The program distributes one book per well-child visit from ages six months to 5 years, for a total of 10 visits. The program costs about $20 per child, said Brian Gallagher, executive director of the national organization based in Boston. Clinics pay for the program through fundraisers, grants or by including it in their budget.

Francesca Vash, a nurse practitioner at Group Health Cooperative’s Capitol Clinic in Madison, said her patient population includes families who are transient or homeless with little access to books.

“No matter the age of the child, I always talk about the importance of reading,” Vash said.

By intervening through the health care system, Navsaria said, medical professionals can keep track of children’s development and model reading techniques to parents in a consistent manner.

“I think it changes how people think about (achievement gaps) — that it could be any one of us and it isn’t a moral failing, this isn’t some sort of irresponsibility, this is the effects of children’s brains being under siege,” Navsaria said.

‘Human capital being wasted’

Courtesy of Parker Hoerz

Some experts say early interventions also are more cost-effective than remedial programs in adolescence and early adulthood.

University of Chicago economist James Heckman found it is cheaper to pay for high quality preschool than later interventions such as hiring teachers to create low student-to-teacher ratios, government-funded job training or rehabilitation programs for ex-convicts.

Heckman’s analysis of low-income African-American children who attended the High/Scope Perry Preschool Program in Ypsilanti, Michigan, during the 1960s found that every $1 invested returned about $7 to $12 back to society.

Investing in programs aimed at older individuals is still beneficial, he wrote, although the return is lower.

“Investing in disadvantaged young children is a rare public policy initiative that promotes fairness and social justice and at the same time promotes productivity in the economy and in society at large,” Heckman wrote.

Pollak said such research shows the “human cost to the human capital being wasted.”

Bipartisan effort to combat poverty

Ed Hubbard, an assistant professor of educational psychology and the director of the Educational Neuroscience Lab at UW-Madison, said Pollak’s research should serve as ammunition for policy changes for Republican and Democratic legislators alike.

“These types of data put the ball squarely back in the politicians’ court,” Hubbard said.

That appears to be happening in Wisconsin. State Sen. Julie Lassa, D-Stevens Point, and Rep. Joan Ballweg, R-Markesan, kicked off the bipartisan Legislative Children’s Caucus in April.

Coburn Dukehart / Wisconsin Center for Investigative Journalism

Lassa said the goal is to advocate for evidence-based public policies that will benefit the state’s children.

To Lassa, Pollak’s research provides proof that poverty harms children.

“To me, there shouldn’t be any more arguing about the science,” Lassa said.

“I think all together the work that (Pollak) is doing is helping us to bring awareness to the necessity to do more comprehensive help when it comes to children,” Ballweg added.

The lawmakers said helping children could have long-term economic benefits.

Said Lassa: “These children are our future workforce, they’re our future leaders. … We need to be making sure that they get the best start possible.”