Obvious though this point seems, there have been surprisingly few studies of just how high a cost disruptive kids exact on the learning of others.
Lori Skibbe and her colleagues have just published an interesting study on the subject.
Skibbe measured self-regulation in 445 1st graders, using the standard head-toes-knees-shoulders (HTKS) task. In this task, children must first follow the instructors direction ("Touch your toes. Now touch your shoulders.") In a second phase, they were instructed to do the opposite of what the instructor said--when told to touch their toes, they were to touch their head, for example. This is a well-known measure of self regulation in children this age (e.g., Ponitz et al., 2008).
Researchers also evaluated the growth over the first grade year in children's literacy skills, using two subtests from the Woodcock-Johnson: Passage Comprehension and Picture Vocabulary.
We would guess that children's growth in literacy would be related to their self-regulation skill (as measured by their HTKS score). What Skibbe et al showed is that the class average HTKS score also predicts how much an individual child will learn, even after you statistically account for that child's HTKS score. (Researchers also accounted for the school-wide percentage of kids qualifying for free or reduced lunch, as academic growth might covary with self-regulation as due to SES differences.)
Thus it would seem that kids who have trouble inhibiting impulses don't just get distracted from their work; when they get distracted from their work they likely engage in behaviors that distract other kids too.
Skibbe then replicated this finding with a second cohort of 633 children in 68 classrooms.
The effects were sizable both for comprehension (d = .35 for cohort 1 and .31 for cohort 2) and for vocabulary (d = .24 for cohort 1 and .16 for cohort 2). To provide some perspective, the effect on comprehension is close to the effect that an effective principal makes to kids' learning (d = .36) according to Hattie's 2009 meta-analysis.
So a calm classroom makes for a better learning environment. Who didn't know that?
Well, I might have guessed that the effect was present, but I wouldn't have guessed it is as large as it is.
To me, this finding also brings to mind the likely importance of peer self-regulation at older grades. Skibbe et al measured self-regulation at first grade, when most teachers still have ready tools to deal with disruptive behavior: most children (but not all, certainly) are ready to yield to teacher's authority.
That's less often true in middle or high school. What tools do teachers have for older kids? What can be done when kids compromise not only their own education, but those of their classmates?
This strikes me as a terribly difficult problem, and one for which I am without ideas. But it seems like a vital problem to address. Skibbe's work tells me that the effects of disruptive peers may be worse than we would have guessed.
Hattie, J. A. C. (2009). Visible Learning. London: Routledge.
Ponitz, C. C., McClelland, M. M., Jewkes, A. M., Connor, C. M., Farris,
C. L., & Morrison, F. J. (2008). Touch your toes! Developing a direct
measure of behavioral regulation in early childhood. Early Childhood
Research Quarterly, 23, 141–158.
Skibbe, L. E. , Phillips, B. M, Day, S. L., Brophy-Herb, H. E. & Connor, C. M. (2012). Children's early literacy growth in relation to classmate's self-regulation. Journal of Educational Psychology, 104, 541-553.