New Research Shows Achievement Gap Grows As Schools Become More Segregated

“We know there are growing concerns over the re-segregation of the nation’s public schools, and this research sheds new light on the achievement gap and our understanding of the impact of school composition on student achievement,” Peggy Carr, acting commissioner of the National Center for Education Statistics, said in a statement.

Researchers found that when they controlled for factors other than race — things like students’ socioeconomic status and teacher quality — that the achievement gap was smaller, leading them to conclude that factors other than race “explained a considerable portion of the observed achievement gap.”  

NCES, an arm of the Education Department, studied the relationship between the percentage of black students in a school and student achievement, as measured by eighth-grade math scores on the 2011 National Assessment of Educational Progress, or NAEP.

Researchers first investigated just the scores of black and white students based on the percentage of black students in a school. They found that all students do worse in schools with a higher percentage of black students, but the achievement gap between black and white students doesn’t change depending on what proportion of a school’s students are black. The achievement gap without factoring in outside conditions was either 25 or 26 points in all schools, no matter the proportion of black students.

They also investigated the gap while controlling for students’ socioeconomic status, as measured by students’ eligibility for free and reduced-price lunch, one indicator of poverty, and by their parents’ education level.

When the students in a school came from families with similar incomes and educational backgrounds, the percentage of them who are black didn’t substantially change the test scores of the white students. However, the performance of the black students — even when their socioeconomic status mirrored their white peers — got worse the higher the percentage of black students in the school, and so the achievement gap widens.

The gap in scores ranged from 18 points in the schools with the lowest proportion of black students to 21 points in the highest-percentage-black schools.

Researchers also attempted to account for other school characteristics, like students’ disability status, teacher qualifications, and school resources. When those factors are considered, the gap between black and white students grew from 15 points at the schools with the lowest density of black students to 20 points at schools with the highest density.

Curiously, the achievement gap when accounting for student, teacher and school factors was much larger for black boys (17 points versus 25 points, from the lowest-black-student-density schools to the highest) than for black girls (13 points versus 15 points).

The report didn’t try to determine specifically why a larger percentage of black students may correlate with lower student achievement or a larger achievement gap, but did suggest several possible reasons, including:

• An uneven distribution of resources, including effective teachers
• A higher proportion of students from lower-income families who need additional academic supports
• Lower expectations of black students from teachers
• A higher number of disciplinary incidents

The racial makeup of the country’s schools also may be exacerbating the problem: Researchers found white students on average attend schools that are 9 percent black, while black students on average attend schools that are 48 percent black. Schools with higher percentages of black students are more likely to be in the South than other regions of the country, and to be in cities rather than suburban or rural settings.