A new study published in The Economic Journal in the United Kingdom attempts to untangle the intertwined influences of cognitive skills and human capital development on adult wages over a person’s lifetime. It’s an ambitious effort that sheds some light on a perennial issue but raises additional questions in the end.
Researcher Uta Bolt from the University of Bristol utilizes longitudinal data from the National Child Development Study (NCDS), which has followed the same cohort of individuals—nearly all people born in the U.K. during a single week in March 1958—for almost 60 years. They were first surveyed via their parents at birth, and followed up at ages 7, 11, 16, 23, 33, 42, 46, 50, and 55. Detailed survey data include information on the circumstances of individuals while growing up—such as parental education and household size—as well as circumstances during adulthood, including wages, occupational choice, and periods of unemployment. Importantly for Bolt’s study, extensive cognitive testing was conducted with individuals at ages 7, 11, and 16, as well as at age 50. Her analytical cohort comprised all those NCDS participants who took part in cognitive testing at age 16 (1974) and at 50 (2008).
It is worth noting, as my Fordham colleague David Griffith does in his podcast review of this report, that the singular term “cognitive skills” is a simplification of a complex comparison. “The measures of adulthood cognitive skills are clearly not identical to the measures of childhood cognitive skills,” Bolt herself writes. “In particular, the age-16 cognitive skills are primarily based on learned concepts (e.g., doing algebra), whereas the age-50 cognitive skills do not require knowledge of any particular learned concept.” The age-50 tests included things like recalling 10 common words read out to them several minutes earlier and a “letter cancellation exercise” where participants were asked to cross out as many “Ps” and “Ws” as they could from a page of random letters within one minute. These test “attention and mental speed” generally, rather than specific verbal or mathematical skills. But Bolt ran additional tests on the two sets of results and ensured their comparability to her satisfaction, writing that her concerns that the tests capture completely different skills were alleviated. She still suggests keeping the variation in testing types in mind when considering the conclusions, which we shall do.
Here are the main regression analysis results: First, childhood cognitive skills persist strongly into adulthood. That is, individuals were likely to show the same skill level—relatively speaking—at 50 as at 16. Second, wages at age 50 are better predicted by cognitive skills at 16 than by cognitive skills at 50. These two findings imply that human capital development may operate on different tracks for cognitive skills versus wages, and the final three findings clarify this. To wit, additional education predicts higher cognitive skills and higher wages, while occupational choice predicts wages, but not cognitive skills at 50. Periods of time spent out of the labor market (a.k.a. unemployment) lower wages but not cognitive skills at 50.
While some of this seems counterintuitive—surely workers get paid in relation to the value of skills they possess—it would make more sense if it is true that cognitive skills and workplace skills operate on separate trajectories. As researcher Bolt puts it, “wages and cognitive skills capture distinct dimensions of adulthood human capital—adulthood investments that predict higher wages do not necessarily predict higher cognitive skills. In fact, education is the only investment which predicts both higher wages and higher cognitive skills at age 50.” All of this is predicated on the cognitive skills measured by the NCDS project at age 16 being the same as those measured at age 50, which we have already suggested may not be the case, despite the robustness checks conducted on the skills test data.
We are left with some interesting information that points to more questions than answers, such as how to best prepare young people for a prosperous future based on their cognitive starting points and how much those cognitive starting points can realistically be boosted if needed.
SOURCE: Uta Bolt, “Cognitive Skills Beyond Childhood,” The Economic Journal (October 2025).
