AUSTIN, Texas — Four-year-olds in the nation’s largest preschool program fare worse with 3-year-olds in their classrooms, according to new research that shows a common practice in most Head Start programs may stunt children’s learning.
Three-fourths of Head Start classes teach 3- and 4-year-old children together, but a new study, led by researchers at The University of Texas at Austin, found that older children make smaller academic gains on average when taught with younger preschoolers. In the classrooms where the two age groups were evenly split, 4-year-olds in the study were an average of nearly five months of academic development behind their 4-year-old peers who were in classrooms without 3-year-olds.
The effect is strong enough, researchers say, to suggest that mixed-age classrooms are preventing some children from starting kindergarten ready to learn math and reading.
“We may be selling Head Start children short if we put 3- and 4-year-old children together,” said Elizabeth Gershoff, an associate professor of human development and family sciences. “We’ve known for a couple of years that 4-year-olds don’t perform as well in Head Start as other children, and this may be a big reason why.”
The study, which used data from more than 2,800 children nationwide in nearly 500 Head Start classrooms, is due to be published in the journal Psychological Science.
Head Start is the nation’s largest federal preschool program, and more than 30 million low-income children, ages 3 to 5, have participated in it during the past 50 years. Past research on Head Start has found that the preschool program has modest effects on children’s academic and social skills, with effects smallest for 4-year-olds.
“Mixed-age classrooms may be one reason that older children don’t seem to benefit as much from Head Start as younger children,” said Arya Ansari, lead author of the study and a graduate student in Gershoff’s lab.
Gershoff and her team used 2009 data from the U.S. Department of Health and Human Services’ national Family and Child Experiences Survey. The survey assessed a representative group of children in Head Start in the fall of 2009 and the spring of 2010, looking at their skills in language and literary, math and social and behavioral measures.
By comparing the performance of children in classes with a greater proportion of 3-year-olds to those with few or no 3-year-olds, the researchers found math and literacy/language differences in the 4-year-old cohort. Even having only a few younger students in the classroom resulted in lower levels of cognitive improvement: for example, with 20 percent of the class made up of 3-year-olds, 4-year-old students experienced about two months of lost academic progress. The impact was greater when the concentration of younger children was higher.
Behavioral skills were not affected by mixed-age classrooms for either age group.
“While there has been some enthusiasm for mixed-age classrooms, our results suggest there may be a significant downside for older children and no real benefit for the younger children,” said Kelly Purtell, a former postdoctoral researcher with Gershoff and now an assistant professor at The Ohio State University.
Researchers don’t know for sure why mixing age groups led to negative effects, but Gershoff says one possibility is that in mixed-age classes, teachers tailor their lessons to be developmentally appropriate for younger children. Compared with 4-year-olds, 3-year-old children know about half as many words, on average, and they have much less familiarity with numbers, letters, more complex sentence construction and concepts of space and time.
Given limited resources and imbalances in enrollment, some Head Start classrooms may not be able to have two separate classrooms for the different age groups, Gershoff notes. Still, the study suggests teachers should explore others ways of helping older preschoolers remain challenged and engaged.
“Teachers can provide 4-year-olds appropriate curriculum even in the same classroom, breaking the children into different groups with their own activities,” she said.
The research was funded in part by the National Institute of Child Health and Human Development.