Early educational intervention programs, like Head Start in the United States or Portage in the U.K., aim to boost the academic achievement of disadvantaged children. By providing additional educational opportunities at an early age, the hope is that children will be better prepared when starting school and that any socioeconomic-based disadvantages will be minimized.

Unfortunately, a common observation is that oftentimes the positive effects of interventions, e.g. in math education, seem to fade after just a couple of years as children who did not receive the intervention catch up academically to those who did. There are two hypotheses as to why this happens. The first is that subsequent academic curricula are to blame. The argument follows that once these children begin their regular schooling, the content being taught is not as challenging as they’re ready for and that often these classes are taught towards the lowest-achieving students. This creates a ceiling for the high-achieving students allowing lower-achieving ones to catch up.

The second theory explaining this fadeout has to do with individual differences in the children. The idea is that though early educational intervention may boost achievement in the short-term, it’s actually the preexisting traits of the children that define the long-term trajectories of their academic careers.

Curriculum vs. individual differences

To look into this, researchers at the University of California, Irvine, the University of North Carolina at Chapel Hill, and the University of Denver teamed up and tried to determine which hypothesis was more likely, the results of which were recently published in Developmental Psychology.

A total of 779 children from 42 low-resource schools were randomly divided into three groups. The first only received early educational mathematics intervention in prekindergarten. The second group received this intervention and in addition, their kindergarten teachers were provided with strategies to build upon the progress made during the prekindergarten intervention. The third group was a control group that received no intervention. All children were tested prior to and after the intervention program and again a year later.

When looking at children that did and did not receive the intervention, those that did outperformed those that didn’t during the post-intervention testing. This effect was still observed at the one-year follow-up though the difference had faded and was not quite as dramatic as it had been a year before. For the children that received additional guidance in kindergarten, the fadeout was reduced.

However, the researchers then looked at the results of the post-intervention test and matched control and intervention-receiving children based on their scores. Those that scored the same were paired together and their pre-test and follow-up scores were compared. Surprisingly, the researcher found that when students were matched, the control groups performed better than the matched intervention group at both the pre-test and the follow-up.

“We looked at what happened to these high-scoring control children compared to the children who received the treatment,” says Drew Bailey, an author of the study and an assistant professor in University of California, Irvine’s School of Education. “What we found is that those that didn’t receive the intervention learned more in the year following the conclusion of the intervention than those that did,” he says.

Additionally, when compared, low-achieving students in the control and intervention groups performed similarly as did high-achieving students in both groups, suggesting that those performing well before intervention will continue to perform well regardless of it. And when it got down to it, these individual differences explained 72 percent of the fadeout effect observed in the intervention versus control analysis.

How to combat fadeout

So what does this mean for early educational interventions? “What we’re not saying is that early interventions are worthless or that it’s a bad idea,” says Bailey, “The question is, what can we learn from this about how teachers or policymakers might optimize children’s learning.”

Bailey points out that this study is better at ruling out an explanation, like classroom content, rather than proposing a solution. And while there are certainly many solutions that have been and will continue to be proposed he stresses that, “we have to test these things directly.”

“The questions they’re asking are really important,” says Matthew Foster, a post-doctoral fellow with the Children’s Learning Institute at the University of Texas Health Science Center at Houston.

“One aspect that they touched on in the article is the home environment,” says Foster who was not involved with the study, “that’s one area of math research that’s just now being examined. Researchers are starting to look at parent-child interactions as they relate to math development.” He points out that there is still a lot of work that needs to be done in that area.

For the future, Bailey would like to look at how to utilize interventions throughout education, not just prior to it and to explore these preexisting differences a little more thoroughly. Says Bailey, “Getting a better idea as to what these differences are and if we can change them is important.”

Follow up studies to this work should look at curricula coherency, according to Foster. “There’s a need for high quality curricular materials that are coherent,” he says, “connections in curricula from prekindergarten to kindergarten to 1st grade, you need that continuity.”

Long-term benefits of interventions

While direct measures are certainly important, one study highlights that the effects of such interventions may take hold in other ways. An early childhood education intervention experiment taking place in the 1960s known as the High/Scope Perry Preschool Program showed initial effects on the children’s intelligence, but those effects faded after a few years.

However, the students were followed up with throughout adulthood. Along with higher graduation rates and completion of more schooling, “Those who received the intervention were less likely to go to jail and made more money,” says Bailey.

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