What Influence Do Peers Have on Preschoolers’ Language Skills?

Preschoolers can learn critical language skills from their better-prepared classmates, a new study finds. The study, “Peer Effects in Preschool Classrooms: Is Children’s Language Growth Associated With Their Classmates’ Skills?” was published in the November/December issue of Child Development.

The research—by Laura M. Justice, Yaacov Petscher, Christopher Schatschneider and Andrew Mashburn—challenges the wisdom of socioeconomically homogenous preschool classrooms, which isolate students with limited language skills from their more advanced peers. About half of American preschoolers are in state- or federally-subsidized programs. The researchers saw plenty of evidence that by virtue of limiting enrollment in public preschools to low-income students, classrooms tended to have high proportions of students with low skill levels, since economically-disadvantaged children often enter school with lower language abilities than their higher-income classmates.

The often-vast vocabulary gap between low-income and middle- or high-income students has been tied to lower academic achievement and higher illiteracy rates later in life. To follow student achievement, the researchers measured children’s language skills with preschool assessments in the fall of the academic year and then again in the spring, to determine whether those students’ language abilities had improved.

Preschoolers’ language abilities in the fall were generally close to class averages, showing that income-based enrollment policies led to classes with fairly homogenous low language skills. But the researchers also found that the class average wasn’t the determining factor of students’ scores a few months later. Instead, the data showed that preschoolers in the low-ability classrooms—children who began the program with limited language skills—saw a more dramatic improvement in their language skills when they were grouped in classrooms with high-skill kids than with children at their own level. 

And although virtually all low-ability students improved their language skills, the gains were proportionally much greater for students who weren’t lagging as much when they started school. Low-ability students who scored in the 25^th percentile in the fall on a series of vocabulary assessments showed some improvement by the spring, but those students still lagged behind the low-ability students who measured in the 75^th percentile in the fall.

Children who began school with higher scores on language assessments were not negatively affected by learning in classrooms with low-skill students. Although high-skill students improved their language skills less significantly than low-scoring students did, the effects of learning alongside low-skill children appeared to be harmless.

The researchers acknowledge their study does not shed light on exactly why learning alongside high-skill students helps low-skill students improve their language and literacy achievement. Less-able students might be directly affected by working closely with highly skilled kids; or there may be a broader effect wherein the teacher approaches a more diverse class with higher expectations than he or she would in a more uniformly low-skill classroom.

So what does this mean? “It might be that classroom composition is affecting growth of language skill, even as much as the content and quality of instruction,” says Justice, one of the study’s authors and an education professor at Ohio State University.  (Petscher and Schatschneider are with the Florida Center for Reading Research at Florida State University and Andrew Mashburn is an associate professor of applied developmental psychology at Portland State University.)

“Policymakers need to think very seriously about how preschool classrooms are composed,” Justice said.

Classes with students of mixed ability levels—and diverse socioeconomic backgrounds—may be more able to help high-risk children grow, learn and become school-ready by the time they enter kindergarten. Teachers aren’t the only people in a classroom affecting student learning; peers matter, too.

UPDATED 1/9/12 with institutional affiliations for the study's authors.