As our nation embarks upon a new year, we must acknowledge a sobering reality: that so many more children could read if only teachers knew how to teach reading. The continued struggle for our children's literacy is both frightening and urgent, but the good news is that we know how to fix it—if only we had the will.

Five decades of research directed by the National Institutes of Health, interpreting America's high rate of reading failure as a public health crisis, has led to a seismic increase in our understanding of how we learn to read—accomplishing the educational equivalent of putting a person on the moon.

With the advent of brain imaging in the 1990s, the work made its greatest leap forward, allowing scientists to interpret the signals sent out by a brain that can read. That's also when the research coalesced into practical guidance schools could apply, beginning with the relatively new insight that children need to be able to decipher the sounds used in speaking before they are even capable of translating letters to sounds. Over a couple of decades, schools have been able to reduce the rate of utter reading failure, from 4 in 10 children down to 3 in 10.

However, if the right methods were genuinely embraced, that failure rate could be fewer than 1 in 10. That's a lot of children to give up on.

Since 2006, the National Council on Teacher Quality has been studying the preparation provided to elementary teachers in reading instruction, reviewing some 4,500 courses required by over 1,100 universities or colleges. In spite of the fact that institutions are awash in reading courses—requiring three or four on average—most dedicate little time to how best to teach reading. See how the teacher preparation programs in your state are doing and pledge to rattle the cage.

Reading courses are most apt to focus on developing teachers' personal philosophies. Rather than studying the research or guidance of experts, they engage in self-reflection. They ask candidates to write about how they learned how to read as children. Then the novice teacher, usually 22 years old, must not only build the plane while flying it, but is told to do so proudly, confident that her professional judgment has not been challenged. More likely she is devastated at her lack of success.

What ideology could possibly trump good reading instruction? It is a fierce ideological obsession that cuts across all facets of teachers' preparation: the belief that every student is so unique that the best teaching practices cannot be applied. As one education professor put it to me, "Even if I knew some practice would be effective 80 percent of the time, I don't include it in my course. I don't want it to color the choices my teachers should be able to make using their own judgment."

That's why we continue to send many more children than necessary into adulthood incapable of not only enjoying a good book, but also engaging as an informed citizen. The original worry of a public health crisis now seems almost trivial in today's dark climate. It may not be necessary to look any further than decades of children not being taught how to read for an explanation for the sorry shape of our democracy.