An achievement gap separating black from white students has long been documented — a social divide extremely vexing to policy makers and the target of one blast of school reform after another. But a new report focusing on black males suggests that the picture is even bleaker than generally known, reports the New York Times. Only 12 percent of black fourth-grade boys are proficient in reading, compared with 38 percent of white boys, and only 12 percent of black eighth-grade boys are proficient in math, compared with 44 percent of white boys. Poverty alone does not seem to explain the differences: poor white boys do just as well as African-American boys who do not live in poverty, measured by whether they qualify for subsidized school lunches. The data was distilled from highly respected national math and reading tests, known as the National Assessment for Educational Progress, which are given to students in fourth and eighth grades, most recently in 2009. The report, “A Call for Change,” is to be released today by the Council of the Great City Schools, an advocacy group for urban public schools. Although the outlines of the problem and many specifics have been previously reported, the group hopes that including so much of what it calls “jaw-dropping data” in one place will spark a new sense of national urgency…