In the years I've spent researching early childhood education, there is one study that is referenced more than any other; the findings from this study have been used to argue for and against early reading instruction hundreds of times.
Everyone in the early childhood space (and especially in academia) is familiar with the renowned The Perry Preschool Project (Schweinhart et al., 1993) and the role it has played in shaping early childhood education. Its results have been consistently offered as evidence of the social and economic benefits of high-quality preschool programs.
I'm going to break down this study piece by piece in an effort to give you a better understanding of what this study really tells us about early childhood education.
Full transparency: The findings of this study very much support what we do at Toddlers CAN Read. But given that the purpose of this blog series is to critically evaluate research studies for their limitations, it would be disingenuous not to give an honest evaluation of a study just because it's in agreement with the practices we promote.
So for the sake of consistency, let's examine the limitations and potential problems with a study widely used to promote the importance of early childhood education.
What did the study test?
A team of researchers led by school psychologist David P. Weikart theorized that enrollment in a high-quality preschool could improve long-term academic and social outcomes for children living in poverty. Their high-quality preschool program intended to emphasize active learning, social-emotional development, and family engagement.
How did they test it?
Beginning in 1962, the researchers sampled 123, 3- and 4-year-olds from the south side neighborhood of Ypsilanti, Michigan. The children were enrolled in the experiment in five groups over the course of 3 years.
The children in the study were African American and from low-income families. The parents of these children had completed an average of 2.6 fewer years of school than the national average, with fewer than 1 in 5 having completed high school. Almost half lived in single-parent households, and the majority lived in homes considered twice as crowded as a typical home at that time.
Participants assigned to the experimental group were enrolled in the researchers' preschool program, the design of which is now known as the High/Scope model. The High/Scope model is characterized by:
- carefully catered instruction based on a child's interests and abilities,
- child-initiated learning based on the Plan-Do-Review process,
- an emphasis on social-emotional development that supports social interactions and builds a secure community, and
- curriculum reflective of the child's community and culture, that also fosters a sense of respect for diversity.
This program included class for 2.5 hours in the morning (Monday-Friday) from October to May. The team of four teachers received extensive training and were said to have received close managerial supervision. The teacher-to-student ratio was 1-to-5/6, and each student received a weekly 1.5 hour home visit from their teachers.
A detailed explanation of the curriculum used can be found in The Cognitively Oriented Curriculum (Weikart, et al., 1979).
The study's authors measured the impact of the preschool program over the course of decades as the students grew older, quantified by education level achieved, performance on aptitude tests, employment rates, criminal behavior, community involvement, use of welfare services, and teen pregnancy rates (among many other things).
What were the results?
In the years that followed, researchers tracked the differences that emerged between participants who attended the study preschool and their peers who didn't- and the results were significant.
By the time the average participant turned 27, data showed that students who participate in the project:
- had significantly higher incomes
- were more likely to own a home
- had significantly fewer arrests
- attended higher levels of schooling
- received fewer social services, including welfare
- had lower rates of teen pregnancy
- spent fewer years in special education
- scored higher on aptitude tests
This list is not exhaustive. It became clear that the study's preschool program had, in fact, led to much better outcomes, both academically and socially, for those enrolled.
In addition, a cost-benefit analysis showed an even broader societal impact. Over the decades that passed, the preschool program returned about $7.16 per dollar spent to the initial public investment. The cost of crime and welfare assistance had decreased in the community, and participants were achieving greater economic success than their peers.
How accurate is our perception of The Perry Preschool Project?
The influence of the Perry Preschool Project cannot be overstated. The astonishing results it generated led to changes in educational practices and policies all over the world. By showcasing the clear benefits of investing in high-quality early childhood education programs, educators and policy-makers alike shifted their priorities around early learning. For example, at least 30 percent of Head Start programs are based on the Perry Preschool Project's model.
Still, taking the results of a study at face-value can be dangerous and misleading, even if they support our own beliefs here at Toddlers CAN Read.
For example, in 2016 early childhood educator Louise Derman-Sparks wrote "What I learned from the Ypsilanti Perry Preschool Project: A teacher's reflections," in which she offered insight into the discrepancies between how the study was presented and how it was actually conducted.
For starters, the cultural mindsets of the researchers leading the study were entirely problematic and did not reflect the beliefs of the teachers at the preschool. Researchers ascribed school failure for students living in poverty to "cultural deprivation," asserting that low IQ scores were the result of what they deemed poor parenting and culture in African American neighborhoods. Essentially, they believed there was a causal relationship between race and low intelligence, and that they could "fix" children by teaching these families how to be better parents.
Thankfully, the teachers in the program did not share this flagrant school of thought. Derman-Sparks and her colleagues rejected the notion of cultural deprivation, and instead attributed poor academic and social outcomes to systemic poverty, inappropriate and biased teaching methods, and racism.
Because of the discrepancies in beliefs between the researchers and teachers, the instruction carried out did not necessarily reflect the practices being portrayed by the researchers in their writings. The teacher's instruction was led by the belief that African American children were just as intelligent as white children and would perform just as well in school if the curriculum respected cultural differences and emphasized strong relationships between teachers and families. This misalignment with researchers' beliefs means the researchers' reporting may not accurately reflect what was happening in classrooms.
Another of Derman-Sparks' concerns was how many of the factors that may have had an influence on the positive outcomes were not evaluated. Specifically, she noted that there was virtually no analysis of:
- teacher attitudes toward their students. Even high-quality curriculum cannot compensate for a teacher's unjust biases regarding, race, ethnicity, class, gender, family structure, religion, and culture.
- teacher-child relationships. Derman-Sparks explained that teachers in the program made a point to develop the students' social-emotional skills through their individual relationships with them.
- home-teacher relationships. Despite the literature suggesting that teachers were conducting home visits each week to "teach" families to be better parents, in actuality they were building partnerships with parents so that both parties would have a better understanding of each child.
- teacher autonomy. Teachers did not instruct students using a one-size-fits-all approach, but instead catered their teaching to the individual needs of each child.
- the impact of racism. By 8 or 9 years old, many students lose the motivation to put in an effort at school due to micro-aggressions from teachers. Internalized racial oppression socializes African American children to begin to buy into any negative expectations that some people (including the researchers leading this experiment) might have of them.
Without these factors having been controlled for, it's difficult to say whether it was the High/Scope curriculum (as explained by the researchers) that explained the positive outcomes for the students in the program.
Finally, Derman-Sparks made it clear that she believes there is a prevailing misunderstanding throughout literature written about the project, where people have come to the conclusion that the High/Scope curriculum is the curriculum followed in the study, and therefore the positive outcomes should be attributed to the High/Scope curriculum. In actuality, the Perry Preschool was not working from the High/Scope curriculum because the High/Scope curriculum did not even exist until 12 years after the study's conclusion in 1967.
This is not to say that the High/Scope curriculum does not carry with it similarities to the curriculum used in the Perry Preschool Project. In fact, in the final 2 years of the study, teachers based instruction around Piaget's theory of children's cognitive development, which would later serve as the basis for the High/Scope curriculum.
Similarities aside, theorizing that positive outcomes were due to the principles of the High/Scope curriculum seems unreasonable considering the curriculum was not yet developed and therefore could not be carried out with fidelity.
What do the results mean?
Unlike the other studies we've reviewed, the Perry Preschool Project has long been used as evidence in support of early learning, rather than as evidence against it.
And although our belief is that early learning can lead to positive outcomes for young children, it would be unreasonable for us to not also carefully analyze the research that supports our beliefs.
The Perry Preschool Project is one of the most influential studies on early childhood education, and it would be extremely easy to take the common explanation of the findings at face-value. Yet upon deeper examination, the study is yet another example of how easily research can be misconstrued to support a belief. It serves as another opportunity to think more critically about how the methods of a study impact the purview of its results, even when those results easily align with what we already think.
What's the bottom line?
The Perry Preschool Project has had a huge impact on early childhood education practices and policies in many countries. The results found that students living in poverty who attended a high-quality preschool program that followed the High/Scope preschool model were more likely to experience positive academic and social outcomes throughout their lifetimes than their peers who did not attend a High/Scope preschool.
Even though positive outcomes were attributed to the High/Scope model, a teacher from the project shared that the High/Scope model (as we know it today) was not followed since it had not yet been created at the time. This leaves us with questions as to what unexamined factors might have influenced the results.