THURSDAY, April 22, 2010 (HealthDay News) -- Why one child excels in reading while another falters is largely due to his or her innate ability, but a new study finds that good teachers do make a difference.
"Kids have differences, and we're not at all saying that genetics don't matter; in fact, they do. But it's not the whole story," said study author Jeanette Taylor, an associate professor in psychology at Florida State University in Tallahassee.
When kids are placed in the best environments for learning how to read, "it really gives them a chance to bring out their best and to reach their potential," she explained. By contrast, low-quality teaching thwarts kids' reading potential.
The study is published in the April 23 issue of Science.
Richard K. Olson, a professor of psychology and a fellow of the Institute for Behavioral Genetics at the University of Colorado at Boulder, co-authored a similar study published in the Journal of Educational Psychology in February. Using twins in the same and different classrooms to examine early literacy achievement, Olson and colleagues concluded that "classroom effects," including teacher quality, account for 8 percent of their differences in performance.
Olsen said the Florida study is different because it doesn't quantify how much of the variability in student performance is accounted for by variability in teachers or classrooms. Rather, it examines the degree to which "genetic influence on student performance seems to vary as a function of how well or how much gain is made in the overall classroom," he said. "It's an interesting perspective, an interesting take on the influence of the class environment."
Twins share half or all of their genes, depending on whether they are identical or fraternal. In theory, that means they should achieve similar results in the classroom if given the same curriculum.
"Genetics play a big role," accounting for 70 percent to 80 percent of variability in children's reading skills, Taylor said.
So what role does the quality of instruction play?
Taylor and her colleagues collected data from 280 identical and 526 fraternal twin pairs in Florida. The sample included roughly equal proportions of black, Hispanic and white kids.
To assess teacher quality, researchers created an index reflecting the amount of reading progress made by the classmates of the twins from beginning of first or second grade to the end of the school year. The index was based on "oral reading fluency" scores, which provide an estimate of how many words in a paragraph a child can accurately read in a minute.
Using that information, the team conducted statistical analyses to figure out whether teacher quality influenced twins' reading performance.
Overall, the study shows that teacher quality makes a difference in reading achievement because it has a moderating effect on genetic differences. At high levels of teacher quality, there was greater genetic variance, "meaning that a good bit of why the kids in those classrooms differ had to do with their genetic differences," Taylor explained.
"It doesn't mean that it erases differences between kids. It allows those differences to emerge and be realized," she added.
Last week, Florida Gov. Charlie Crist vetoed a teacher pay and tenure bill that would have based teacher evaluations used in determining teacher pay, in part, on student achievements, the Miami Herald reported. The governor called the bill "significantly flawed," it said.
But the idea remains alive and well. Lawmakers in a number of states are considering linking teacher pay to student performance.
The problem, Taylor reasoned, is that kids bring their own differences to the classroom, including behavioral problems, learning disabilities and difficulties with English. "I think requiring that teachers pay be tied to performance is a really dangerous and a problematic idea just given the state of science," she said.
Olson echoed those concerns. "It's laying the blame on teachers for kids struggling. It's not fair and, I'll tell you, teachers are getting pretty fed up with it," he said.
The U.S. Department of Education has more on improving student reading performance.