Rethinking the traditional idea of a peak
For years, the common narrative has suggested that intellectual power peaks in early adulthood and gradually wanes as time goes on. Yet a recent study by my colleague and me, published in Intelligence, offers a more optimistic and nuanced view: for many people, overall psychological functioning peaks between ages 55 and 60. This finding challenges conventional wisdom and provides a fresh lens on how we think about careers, leadership, and aging.
Beyond raw IQ: the shape of psychological strength
While raw intellectual abilities—the rapid reasoning, memory, and information processing that often grab headlines—tend to decline after the mid- twenties, our research focused on a broader set of psychological traits. We selected 16 dimensions that are well-documented, endure over time, and reliably predict real-world performance. By standardising data from large-scale studies, we could compare how each trait evolves across the lifespan and map their distinctive trajectories.
Late bloomers and the power of temperament
Certain traits reach their apex much later than traditional intelligence measures. For example, conscientiousness peaks around age 65, and emotional stability around age 75. Even less-discussed dimensions, such as moral reasoning, show late-life strengthening. Notably, the capacity to resist cognitive biases—those mental shortcuts that can derail judgment—may continue improving well into the 70s and 80s. In the aggregate, these late-blooming traits can compensate for declines in other domains and support sound decision-making in complex situations.
The overall arc: from peak functioning to careful leadership
Putting the pieces together, the study finds that overall mental functioning tends to peak between 55 and 60, with a gradual decline beginning around 65. The decline accelerates after about 75. This pattern helps explain why many demanding leadership roles in business, politics, and public life are held by people in their fifties and early sixties: a convergence of deep experience, refined judgment, and stable temperament can outweigh some reductions in raw cognitive speed.
Implications for the workforce and policy
These findings have practical consequences for how organizations recruit, develop, and support aging talent. Rather than viewing age as a blunt metric of capability, employers can recognize the unique strengths that tend to crystallize in later life. Experienced leaders may demonstrate better strategic foresight, balanced risk-taking, and more measured decision-making—qualities that matter in volatile markets and high-stakes environments.
However, age can also bring challenges. Our research acknowledges that older workers often face barriers to re-entry after career setbacks and may encounter structural hurdles in hiring. In some roles, mandatory retirement ages or retirement incentives influence hiring decisions and workforce planning. Understanding the complementary mix of preserved skills and potential declines is essential to creating inclusive, performance-driven workplaces that value both experience and up-to-date expertise.
What this means for individuals and organizations
For individuals, the message is hopeful: growing older can bring a different kind of peak—one rooted in experience, judgment, and resilience. For organizations, the takeaway is strategic: nurture roles that leverage late-life strengths, invest in ongoing development for all ages, and design pathways that keep experienced professionals engaged. When teams harmonize the endurance of age with the agility of newer entrants, they can achieve sophisticated problem-solving and leadership outcomes that neither group could accomplish alone.
Moving forward with an evidence-based optimism
Our study does not deny that some abilities may wane with age, but it emphasizes a broader, more dynamic picture of human potential. By documenting the diverse age trajectories of multiple psychological traits, we hope to inspire a more nuanced conversation about aging, work, and capability. If we redefine peak age as a mid-to-late-life advantage, we open the door to healthier aging, smarter leadership, and workplaces that value the full spectrum of human development.
