Teacher Quality Moderates the Genetic Effects on Early Reading
J. Taylor, A.D. Roehrig, B. Soden Hensler, C.M. Connor, C. Schatschneider
April 23, 2010
This unique teacher effectiveness study examined the reading test scores of roughly 800 pairs of twins in 1st and 2nd grade Florida classrooms. Included were both identical twins, who share 100 percent of their genes, and fraternal twins who share roughly 50 percent. Because twins share these genetic similarities and also have the same family background—two factors that traditionally complicate teacher effectiveness studies—researchers could better isolate the role that teachers play in advancing student achievement. Analysts found that, among identical twins with different teachers, those whose teachers were deemed more effective—as measured by the gain scores of their entire class—tended to have higher scores on oral reading tests than their siblings who had less effective teachers. In addition, when examining both fraternal and identical twins, researchers concluded that, “Genetic variance in oral reading fluency was greater at higher levels of teacher quality.” Translation? When students have a good teacher, they are more likely to reach their genetic potential (and when they don’t, they are not). The study has several shortcomings, including not addressing factors like peer effects, operating in a short timeframe of observation, and holding a narrow view of reading aptitude (as gauged by oral reading fluency). It nonetheless adds to a voluminous pile of teacher effectiveness research that sing the same tune: Teachers matter a lot. Furthermore, studies like this begin to answer an important question about children who are not twins (the vast majority!): How much of variability in reading achievement is the result of nature vs. nurture? Find the study (for a small fee) here.