An encouraging new study suggests we may hit our "functional capacity" later in life than previously believed.
It may be a commonly held belief that humans reach our physical and cognitive peak sometime in our twenties—thanks in part to factors such as brain volume and cardiovascular health—but there’s plenty of reason to remain optimistic as we grow older. For one: having a positive attitude about aging can have a direct impact on our health and longevity, according to Harvard experts. But recent research provides a whole new reason for hope: as it turns out, our true cognitive prime might occur during the later portion of midlife.
Set to be published by a group of psychology researchers in the journal Intelligence, the November 2025 study acknowledges that fluid intelligence, a typical marker of cognitive function, does in fact peak around age 20 and decline throughout adulthood. However, the study’s text rejects this as the sole measure of cognitive ability, or a primary predictor of important life outcomes.
“Human achievement in domains such as career success tends to peak much later, typically between the ages of 55 and 60,” the study states. “This discrepancy may reflect the fact that, while fluid intelligence may decline with age, other dimensions improve.” These other factors include “crystallized intelligence [and] emotional intelligence,” they add.
To understand how the mind changes with age, the team applied “nine constructs associated with life success” to previously published studies on aging. These included:
- Cognitive abilities
- Personality traits
- Emotional intelligence
- Financial literacy
- Moral reasoning
- Resistance to sunk-cost bias
- Cognitive flexibility
- Cognitive empathy
- Need for cognition
The researchers then developed a Cognitive-Personality Functioning Index (CPFI) and compared two weighting approaches—a Conventional Model, emphasizing intelligence and core personality traits, and a Comprehensive Model, integrating all nine dimensions of cognitive function. Both identified that cognitive function peaked during late midlife, between the ages of 55 and 60, “but diverged at the younger and older ends of adulthood.”
Younger people scored higher than older adults when they used the Conventional Model, but when the team used the Comprehensive Model, “the two groups were roughly equivalent,” the authors say. They continue that the findings challenge “many conventional assumptions about age and capability,” suggesting that midlife “may represent the true apex of psychological readiness.”
Gilles Gignac, PhD, lead author of the study and a professor of psychology at the University of Western Australia, tells The Healthy by Reader’s Digest that these “more subtle and less linear patterns” suggest “a nuanced and complex trajectory”—one that contradicts the simple narrative of early peak and steady decline.
Yet one finding in the study appeared clear—and especially relevant as Americans continue to have conversations around age limits for politicians and other positions of power in particular: “Individuals best suited for high-stakes decision-making roles are unlikely to be younger than 40 or older than 65.”
“It’s the accumulation of knowledge, emotional stability, and moral reasoning, for example, that shifts the peak of overall functioning into late midlife,” says Dr. Gignac. “Youth brings speed and raw processing power, but with age comes a broader toolkit for navigating complex, high-stakes challenges.”
Continues Dr. Gignac: “What’s new here is that, for the first time, all these dimensions have been considered together to reveal how they combine to produce a clear age-related peak.”
For daily wellness updates, subscribe to The Healthy by Reader’s Digest newsletter and follow The Healthy on Facebook and Instagram. Keep reading:
- Study: Cognitive Declines After a Stroke Affected This Group More Than Others
- New Study: Eating This Unique Mineral Now Could Enhance Brain Function Later
- Over 60? Eating More of This Could Help You Live Longer, Suggests Curious New Study
- Drinking This Hot Beverage Daily Could Help Preserve Brain Health, Found New Harvard Study
