Is the decline in adult literacy related to student reading scores? Part 1

by Michael Keany

Over the last forty years, two “national thermometers” of literacy have moved in ways that invite comparison: NAEP Grade 4 reading (how U.S. children are reading in elementary school) and adult literacy assessments (how U.S. adults perform on large-scale literacy tasks). When you place these trends side by side, the story is less “one mirrors the other” and more “they may share some underlying conditions—but they’re not measuring the same population at the same time.”

What the two trend lines actually show

NAEP Grade 4 reading rose modestly from the early 1990s into the mid-2010s, then slipped, with a sharper drop after 2019. In the most recent national results, Grade 4 reading in 2024 is lower than 2022 and 2019.

Adult literacy, as measured by international assessments like PIAAC (and earlier national/international studies), is more intermittent—but it also shows a recent downturn. The U.S. adult literacy average in 2023 (258) was 12 points lower than 2017 (271).

So yes: both series show declines in the most recent period. The key question is whether that is a correlation in a meaningful sense.

Is there a correlation between the declines?

If “correlation” means “the lines both tilt down at about the same time,” then there is a surface-level alignment: NAEP Grade 4 reading declines notably after 2019, and adult literacy drops between 2017 and 2023.

But if “correlation” means “the Grade 4 students scoring lower are the same people causing the adult literacy decline,” then no—not yet, and not directly. The adults tested in PIAAC 2023 are ages 16–65, meaning most were in elementary school many years (often decades) before 2023. A 10-year-old in 2024 won’t appear in adult literacy samples for a long time. That creates a built-in time lag that prevents any tight, near-term statistical relationship between “today’s Grade 4 scores” and “today’s adult scores.”

What you can reasonably infer

Even without a direct cohort link, it’s reasonable to treat the two declines as signals that literacy development and maintenance are under pressure across the life span. NAEP’s post-2019 slide is widely read as evidence of disrupted instructional time, uneven attendance, and reduced reading volume during and after the pandemic years. Adult literacy’s 2017→2023 decline is reported as a national average drop, suggesting broad-based challenges in literacy skills among working-age adults, not just a small subgroup.

What could connect them? Not a simple cause-and-effect across the same people in the same year—but potentially shared drivers, such as:

• reduced sustained reading practice,

• widening opportunity gaps,

• and changing literacy demands (digital reading, workplace documentation, online information environments).

What research suggests about the long-run linkage

Over the long haul, early reading skills do matter. Longitudinal research has found that early reading predicts later reading outcomes well into adulthood, reinforcing the idea that sustained drops in elementary reading can foreshadow future adult skill distributions—just not immediately.

Bottom line for educators and leaders

Right now, the safest conclusion is:

• There is a parallel downward movement in recent years, but

• a direct correlation is weak because the tested populations don’t align in time, and

• The more meaningful “connection” is prospective: if elementary reading remains depressed for multiple cohorts, adult literacy measures may reflect that years later.

That makes today’s NAEP decline more than a headline—it’s an early warning indicator.

Five references that support these findings

1. NAEP 2024 national Grade 4 reading results and comparisons to 2022/2019.

2. NCES Condition of Education: NAEP reading performance context (1992–2022).

3. IES press release on PIAAC 2023 U.S. adult literacy (258) vs 2017 (271).

4. NCES PIAAC 2023 national results page showing declines between 2017 and 2023.

5. Longitudinal evidence linking early reading to adult reading outcomes.

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Prepared with the assistance of AI software

OpenAI. (2025). ChatGPT (4) [Large language model]. https://chat.openai.com