IQ Isn't the Best Predictor of Academic Success. Here's What Is.

By Lauren Bochicchio Beaver 

For most of the last century, IQ was education's north star. Test a child early enough, the thinking went, and you could predict how far they'd go in school. Whole programs were built around it. Careers were written about it. Parents stressed over it.

But here's what the research is actually showing us now: IQ isn't the strongest predictor of academic success. Something else is — and the really exciting part? It can be taught.

For most of the last century, IQ was education's north star. Test a child early enough, the thinking went, and you could predict how far they'd go in school. Whole programs were built around it. Careers were written about it. Parents stressed over it.

But here's what the research is actually showing us now: IQ isn't the strongest predictor of academic success. Something else is — and the really exciting part? It can be taught.

That something is executive function (EF): the set of mental skills that help us focus, hold information in mind, manage impulses, and switch gears when needed. Researchers have spent the last two decades studying how EF connects to learning outcomes, and what they've found is reshaping how we think about academic potential.

Let's walk through three studies that make the case.

Study 1: Working Memory Beats IQ as a Predictor of Academic Success

Alloway & Alloway (2010)

Tracy Packiam Alloway and Ross Alloway followed 98 kids from age 5 to age 11. They measured working memory and IQ when children started school, then checked in on their literacy and numeracy outcomes six years later.

Their core question: is working memory just a fancy way of measuring IQ, or does it tell us something different?

Turns out — very different. Working memory at age 5 was the single strongest predictor of how well kids did in both reading and math six years later. It accounted for 21% of numeracy outcomes on its own. IQ? It added another 6%.

The researchers put it simply: "Working memory at the start of formal education is a more powerful predictor of subsequent academic success than IQ."

So what is working memory, exactly? It's the ability to hold information in mind while you're actively using it — keeping track of the steps in a math problem, following the thread of a story while you're reading, remembering what the teacher just said while you write it down. Holding the scanner image during Skylar’s Run and choosing the correct smog bot that matches. It's one of the core components of executive function. And unlike IQ, it can be strengthened.

Study 2: Executive Function Matters at Every Age, in Every Subject

Best, Miller, & Naglieri (2011)

The Alloway study showed EF matters at school entry — but what about later? Best and colleagues wanted to know whether the EF-to-achievement connection holds throughout childhood and adolescence, and whether it spans different academic subjects.

They studied 2,036 kids and teens between ages 5 and 17 — a nationally representative sample — measuring executive function and tracking reading and math achievement over time.

Here's what they found:

EF predicted academic performance all the way through age 15, not just in the early years. The connection didn't fade as kids got older and more experienced in school, but held.

Even more striking: the relationship between EF and achievement was essentially the same for math and reading. The same cognitive skills that helped kids succeed in one subject helped them in the other. EF isn't a math thing or a reading thing — it's a learning thing.

Perhaps most importantly for educators thinking about intervention: the research confirms that EF influences academic achievement, not the other way around. The cognitive capacity comes first, and the learning outcomes follow. That means building EF isn't just a nice-to-have — it's the cognitive foundation on which learning happens.

Study 3: Strong Executive Function Can Change a Child's Trajectory

Ribner, Willoughby, & Blair (2017)

This one is our favorite — because it's not just about predicting outcomes. It's about changing them.

Ribner and colleagues followed 1,292 children from rural communities in two U.S. regions — kids who faced real socioeconomic challenges and entered school with the kinds of early skill gaps that tend to predict long-term academic struggles. They measured EF at age 5 and tracked math and reading all the way through 5th grade, controlling for IQ, processing speed, vocabulary, and early academic skills.

EF at age 5 still predicted 5th grade outcomes above and beyond all of those factors. But here's the part that really matters: for kids who started school behind, stronger EF acted as a buffer. It narrowed the gap between low early achievers and their higher-achieving peers by 5th grade. High EF didn't erase disadvantage, but it gave children a significantly better shot at closing the gap over time.

The takeaway: early academic struggles don't have to define a child's trajectory. When executive function is strong, kids are more likely to catch up. When it's weak, the gap tends to grow — regardless of raw intelligence.

What These Three Studies Are Telling Us

Read together, these papers point to something pretty significant:

The cognitive skills that best predict academic success aren't fixed — and they can be trained.

Working memory, focus, impulse control, cognitive flexibility — these aren't traits children either have or don't. They develop. They respond to practice. And when they're strengthened, kids show real, lasting gains in the classroom.

For children who enter school already behind — whether because of attention challenges, learning differences, or socioeconomic disadvantage — this is genuinely hopeful news. The gap isn't simply a reflection of who they are. It's a reflection of skills they haven't yet had the chance to build.

This Is Why We Built Thynk

Skylar's Run wasn't designed to teach math or reading directly. It was designed to train the cognitive skills that make math and reading possible in the first place.

The curriculum starts with attention. Without sustained focus, none of the other executive functions can fully operate. From there, it builds through inhibitory control, cognitive flexibility, and working memory: the exact skills these three studies point to as the most powerful predictors of long-term academic success.

And the results we're seeing reflect what the science predicts. After 6–8 weeks of training, students show a 34% improvement in attention and impulsivity, gains of up to 13.7 months in reading fluency, and up to 11.6 months in math fluency.

When you strengthen the foundation, everything built on top of it gets stronger too.

The question IQ answers is: how smart is this child?

The question executive function answers is: is this child ready to learn?

For educators, that second question is the one that actually changes outcomes.

Curious about what Thynk looks like in a school setting? Visit thynk.com or reach out to our team to learn more about bringing Skylar's Run to your students.

Sources:

Alloway, T. P., & Alloway, R. G. (2010). Investigating the predictive roles of working memory and IQ in academic attainment. Journal of Experimental Child Psychology, 106(1), 20–29.

Best, J. R., Miller, P. H., & Naglieri, J. A. (2011). Relations between executive function and academic achievement from ages 5 to 17 in a large, representative national sample. Learning and Individual Differences, 21(4), 327–336.

Ribner, A. D., Willoughby, M. T., & Blair, C. B. (2017). Executive function buffers the association between early math and later academic skills. Frontiers in Psychology, 8, 869.