We are shortchanging America’s brightest students, and we’re doing it reflexively and furtively. A big part of the problem is our desire to duck hard choices when it comes to kids and schooling. “Differentiated instruction” — the notion that any teacher can simultaneously instruct children of wildly different levels of ability in a single classroom — is appealing precisely because it seemingly allows us to avoid having to decide where to focus finite time, energy and resources.

Truth is, few teachers have the extraordinary skill and stamina to constantly fine-tune instruction to the needs of 20- or 30-odd students, six hours a day, 180 days a year. What happens, instead, is that teachers tend to focus on the middle of the pack. Or, more typically of late, on the least proficient students.

In 2008, a survey of the nation’s teachers found that 60 percent said struggling students were a “top priority” at their schools, while just 23 percent said the same of “academically advanced” students. Eighty percent said struggling students were most likely to get one-on-one attention from teachers; just 5 percent said the same of advanced students.

RAND Corporation scholars have previously determined that low-achieving students benefit when placed in mixed-ability classrooms (faring about five percentage points better than those placed in lower-track classes) but that high-achievers fared six percentage points worse in such general classes.

In the past decade, would-be reformers have focused relentlessly on closing “achievement gaps,” leaving advanced students to fend for themselves. The Brookings Institution’s Tom Loveless has reported that, while the nation’s lowest-achieving students made significant gains in reading and math between 2000 and 2007, the progress by top students was “anemic.” And it’s not as if we can afford to coast. Just 6 percent of U.S. eighth graders scored “advanced” on the 2007 international math and science assessment, while more than a dozen nations fared at least twice as well.

Focusing on the neediest students, even at the expense of their peers, is not unreasonable. After all, we can't do everything. But self-interest and a proper respect for all children demand that we wrestle with such decisions and pay more than lip service to the needs of advanced students. Instead, in the past decade, many reformers have sought to stifle those who dare even to suggest there are trade-offs — branding such sentiments ill-informed or even racist.