By Betsy Hill and Roger Stark
Editor’s Note: This is part one of a two-part series.
Businesses often talk about the 80/20 rule—20 percent of customers produce 80 percent of revenue, or 20 percent create 80 percent of service calls. A similar pattern appears in education, but our observations suggest a different ratio: roughly a 30/70 distribution in student performance and underlying cognitive skills.
Consider this: students who score around the 70th percentile on cognitive ability assessments such as the CogAT (or the Canadian CCAT) typically learn and perform at grade level without major modifications to curriculum or instruction. That 70th-percentile threshold represents about 30 percent of the student population.
National data aligns with this distribution. In the United States, roughly 37 percent of fourth graders read at grade level and about 40 percent perform at grade level in fourth-grade math. By eighth grade those percentages fall closer to 30 percent. Those outcomes are consistent with the idea that about 30 percent of students are likely to meet grade-level expectations given standard instruction and curriculum—hence a practical “30/70 rule.”
Our experience working in schools, especially those serving high percentages of students in poverty (Title I and similar contexts), reinforces this pattern. In high-poverty urban schools we often find that about 70 percent of students show meaningful deficits in attention and/or working memory, compared with roughly 30 percent in more affluent suburban settings. Such deficits predict academic struggle and often require substantial adjustments to teaching approaches and curriculum. This is another manifestation of a 70/30 split—70 percent of students needing additional supports while 30 percent function well with standard expectations.
Across any population there will be a top 30 percent and a bottom 70 percent. Of course, the composition of that top 30 percent varies: the top third at an elite institution will likely score higher on cognitive measures than the top third in a general population. We cannot make every student score at the 70th percentile overnight, but we can ask a different, practical question: what if more students reached the cognitive capacity associated with learning without curricular adjustments—that is, what if more students achieved the level of cognitive skills required to perform at grade level?
There is strong evidence that many students are not performing at grade level because their cognitive capacities—skills like working memory, attention, and processing speed—are underdeveloped, not simply because they lack effort or because curriculum and instruction are inherently inadequate. Cognitive skills explain a large share of the variance in academic performance, often more than other commonly measured indicators.
It is important to clarify what we mean by cognitive capacity: it is developed over time and can be improved. Saying a child has less-developed cognitive skills does not mean they cannot learn as well as others; it means they have not yet developed the cognitive resources needed to meet certain grade-level expectations. As one education observer put it, “If most students are not performing at grade level, then how can that be grade level?”
Putting debates about exact grade-level standards aside, the practical point is this: whatever content and skills schools expect students to master at any point, students also need sufficient cognitive capacity to do that work. Currently, a little under a third of students typically meet those expectations under standard instruction. Some students perform at grade level despite lower scores on cognitive assessments, and that should be recognized. But if cognitive growth is possible, then larger gains may be achievable.
Research shows promising results. Interventions that raise students’ cognitive capacity to around the 70th percentile have produced roughly a year and a half of academic growth in approximately 12 weeks. Achieving 1.5 years of growth in a single school year is a major challenge for most schools, and compressing that growth into three months is remarkable. Yet studies indicate this level of accelerated growth can be realized, offering a pathway for many more students to reach grade-level performance.
Imagine reversing the 30/70 pattern so that a majority of students perform at the cognitive level associated with grade-level mastery. The potential returns—in student outcomes, life opportunities, and societal productivity—are enormous. In part two of this series we will examine the economic implications and lay out how broader cognitive development could translate into substantial gains for individuals and communities.
About the Authors
Betsy Hill is President of BrainWare Learning Company, an organization focused on building learning capacity through practical applications of neuroscience. An experienced educator, she has studied the intersection of neuroscience and education and has served as chair of the board of trustees at Chicago State University. She also teaches strategic thinking in an MBA program and holds a Master of Arts in Teaching and an MBA from Northwestern University.
Roger Stark is Co-founder and CEO of BrainWare Learning Company. For more than a decade he has advocated making comprehensive cognitive skills training and assessment widely accessible. His work led to the development of an integrated cognitive literacy training tool delivered online. Stark’s efforts draw on decades of clinical collaboration and focus on affordable, effective approaches to improving cognitive capacity for learners.
This article was originally published by The Learning Counsel, a research institute and news media hub focused on the shift in education to digital curriculum.