The start of a school year should be a time of exciting new opportunities for all children, and maybe a little sadness that the summer is over. But 1 in 5 children in the United States live in poverty, which makes them likely to start the school year already behind their higher-income peers. This phenomenon is sometimes referred to as the “income achievement gap.”

Often, “achievement gap” refers to racial disparities in academic achievement—the fact that students of color tend to lag behind their white peers in terms of school readiness, test scores, educational attainment, and grades. The income achievement gap, on the other hand, is the disparity in academic achievement between students from high-income families and their less-affluent peers. Stanford researcher Sean Reardon, a frequently cited expert on the topic, has found that the gap in reading and math test scores between children in families with low and high incomes was twice as large as the gap between white and black students, for example.

Furthermore, while the black-white achievement gap has narrowed over time, the gap between high- and low-income students grew as much as 40 percent, when comparing children born in the 1970s to those born in 2001. Reardon’s latest research, using more recent data, indicates that the income achievement gap may have narrowed over the last 10 years. But even with this promising development, the gap is closing so slowly that Reardon and his colleagues estimate it would take at least 60 years for it to disappear completely.

Early onset

Income-related achievement disparities can emerge as young as infancy. Pre-kindergarten-age children living in poverty are less likely to possess cognitive and early literacy-readiness skills than children living above the poverty threshold. For example, data have found that only 46 percent of 3- to 6-year-olds living in poverty are able to write their names, compared with 64 percent of those living above poverty. The difference in cognitive skills between low- and high-income children is already apparent when they enter kindergarten, and research tends to find that it holds steady from there. In other words, children from low-income households typically enter school behind their peers and never catch up.

Many obstacles, many solutions

Unfortunately, we still don’t know all the reasons why the income achievement gap exists, or why it has grown over time, but we have some probable explanations.

Children in lower-income households are less likely to have access to high-quality, learning-rich environments—in the home, in early care settings, or in schools. By comparison, high-income parents are able to invest more time and financial resources in their children’s education and in a home environment that is cognitively stimulating. Children in higher-income households are more likely to be read to regularly and exposed to a larger vocabulary. And higher-income parents vastly outspend low-income parents on other enrichment activities  such as summer camps, extracurricular programs, and outside-of-school lessons.

Poverty threatens child development at more fundamental levels, as well. Neuroscientists have begun to measure poverty’s association with differences in children’s brain structure, particularly the areas of the brain that are related to language, reading, executive functioning, and spatial skills.

Girls and boys in poor and low-income families tend to have less access to nutritious foods during critical periods of brain development. They are more likely to live in neighborhoods where they are exposed to environmental toxins such as lead and toxic levels of stress (for example, from frequent or prolonged exposure to violence), both of which can impair cognitive development.

Given the multiple obstacles to lower-income children’s academic achievement, the solutions will have to stretch beyond the educational system, and include parents, caregivers, and communities. The best-case scenario would be to move more families out of poverty, but as a country we have not yet determined how to do that most effectively. Fortunately, there are a few proven or promising solutions that may help narrow the achievement gap for children who live in poverty now.

For low-income families, we can provide parents with support and education on positive parenting techniques and the importance of early brain development. One example of a successful approach is home visiting programs, in which trained professionals such as nurses conduct in-home visits with low-income parents, starting as early as pregnancy.

Outside of the home, we can expand access to high-quality preschool and early care for young children. My colleagues recently wrote about new legislation to improve families’ access to and awareness of Head Start and child care subsidies. Such strategies reap double benefits: young children get a boost in their readiness for school, and parents are supported in their efforts to maintain or improve their employment prospects, perhaps pursuing further education of their own. There are also some promising approaches for high-poverty schools, such as integrated student supports and focusing on accountability.

It is also critical that we address additional non-cognitive barriers to learning and healthy development, such as toxic stress. For example, many schools and early care settings are now using trauma-informed approaches to buffer children from the effects of adverse experiences and build strategies, such as mindfulness, that can improve critical executive function skills, such as self-control.

Income inequality has been an important talking point in the presidential campaign so far, and we’re sure to hear a lot more about it before Election Day, though neither candidate has given much airtime to disparities in academic achievement. Until we find a way to help the millions of low-income children in this country who are heading into the school year behind their higher-income peers, we’ll have a long way to go toward achieving equality.