A science-technology-society approach to understanding ageing beyond chronological years
Meet two 75-year-olds. One trains for marathons, manages a community garden, and video-calls grandchildren across the globe. Another struggles to climb stairs, forgets recent conversations, and rarely leaves their apartment. Chronologically, they're identical. Functionally, they're decades apart.
This paradox lies at the heart of one of the most significant transformations in how science understands human ageing. Functional ageing—a revolutionary approach that shifts focus from how long we've lived to how well we live—is redefining what it means to grow older in the 21st century. As the world undergoes an unprecedented demographic transformation with one in six people projected to be over 60 by 2030, understanding functional ageing has become both a personal and societal imperative 1 .
The conventional medical model that views ageing as a problem to be solved is giving way to a more nuanced understanding: ageing is a life course process profoundly influenced by the dynamic interplay between our biology, the technologies we use, and the societies we build. This science-technology-society approach reveals that our functional trajectory—our ability to do what we value—isn't predetermined but can be shaped across our entire lives.
Simply the number of years since birth. A fixed measurement that doesn't reflect individual capabilities or health status.
A measure of capabilities and performance. Dynamic and modifiable through lifestyle, environment, and interventions.
Traditionally, ageing has been measured in years—a straightforward count of trips around the sun. This chronological approach has dictated everything from retirement ages to medical treatments, often with little regard for actual capability. The limitations are stark: when the World Health Organization analyzed healthcare systems worldwide, they found that chronological age alone frequently determined treatment decisions, potentially reinforcing ageism and leading to flawed medical reasoning 3 .
The functional approach offers a transformative alternative. The WHO now defines healthy ageing as "the process of developing and maintaining the functional ability that enables wellbeing in older age" 8 . This isn't about avoiding disease altogether—many older adults manage health conditions successfully—but about maintaining what we value: the ability to move, think, connect, and contribute.
| Traditional View | Functional Ageing Perspective |
|---|---|
| Focus on chronological age | Focus on functional ability |
| Ageing as decline | Ageing as life course development |
| Disease-centered | Ability-centered |
| Reactive care | Preventive maintenance |
| Biological determinism | Bio-psycho-social integration |
What exactly do we mean by "functional ability"? The WHO breaks it down into five key domains: meeting basic needs; learning and making decisions; mobility; building relationships; and contributing to society 8 . These capabilities emerge from the interaction between our intrinsic capacity—our physical and mental capacities—and the environments we inhabit.
The biological foundations of functional ageing are complex and multifaceted. Research has identified several hallmarks of ageing that contribute to functional decline, including genomic instability, telomere attrition, mitochondrial dysfunction, and cellular senescence 3 6 . However, these molecular processes don't tell the whole story. Two people with similar biological markers may have dramatically different functional abilities based on their environments, behaviors, and opportunities.
The gap between lifespan (how long we live) and healthspan (how long we stay healthy) underscores the importance of the functional approach. Between 2000 and 2019, global life expectancy rose by 6.4 years, yet healthy life expectancy grew by just 5.3 years 1 . That means people are living longer but spending more time in poor health—a critical challenge that functional ageing seeks to address.
Data adapted from Global Burden of Disease study 1
While dramatic diseases often capture medical attention, functional decline typically occurs gradually, almost imperceptibly, before manifesting as disability. Understanding this trajectory required shifting from laboratory biomarkers to real-world performance measures. A pivotal series of longitudinal studies revolutionized our understanding of when and how functional abilities change with age.
One crucial investigation emerged from the Health and Retirement Study, which followed 6,874 community-dwelling adults aged 50-64 over ten years. Unlike previous research focused on the "oldest old," this study targeted the critical period when functional decline often begins—middle age 6 .
The research team employed standardized, performance-based assessments rather than relying solely on self-reports:
The findings revealed a startling reality: functional limitations begin much earlier than previously assumed. By age 64, 22% of participants already had difficulties with basic activities like dressing, while 19% struggled with instrumental activities like managing finances 6 .
Perhaps most importantly, the study discovered that 37% of those who developed functional limitations recovered within two years, suggesting early functional decline may be reversible with appropriate interventions. This challenged the long-held assumption that functional loss was inevitably progressive and irreversible.
The research provided robust evidence that the foundations of functional ageing in later life are built in midlife, highlighting a critical window for intervention that could potentially alter the entire trajectory of ageing.
| Type of Limitation | Specific Activities Affected | Cumulative Incidence by Age 64 |
|---|---|---|
| Activities of Daily Living (ADLs) | Dressing, bathing, eating, transferring, toileting | 22% |
| Most common ADL: Dressing | 14% | |
| Instrumental ADLs (IADLs) | Shopping, managing money, meal preparation, using telephone | 19% |
| Most common IADL: Shopping for groceries | 10% |
How do researchers and clinicians quantify something as complex as functional ability? The field has developed sophisticated tools that move far beyond simple age-based assumptions:
Measures basic self-care abilities including bathing, dressing, toileting, transferring, continence, and feeding. This scale serves as a fundamental assessment of independence 3 .
Assesses more complex skills needed to live independently in the community, such as using the telephone, shopping, food preparation, housekeeping, laundry, transportation, medication management, and handling finances 3 .
A standardized objective assessment tool that evaluates lower extremity function using three components: standing balance, walking speed, and ability to rise from a chair repeatedly 3 .
Comprehensive assessment of 18 daily activities across motor and cognitive domains, with each item scored from 1 (total assistance required) to 7 (complete independence) 3 .
These tools have revealed that functional decline follows patterns—often appearing first in more complex activities before affecting basic self-care. They've also helped identify that recovery is possible, especially when limitations are identified early.
Functional ageing represents a perfect convergence of biology, technology, and society—each influencing and being influenced by the others. The socio-material perspective recognizes that technology doesn't merely solve problems of ageing but actively shapes what ageing means and how it's experienced .
Gerontechnologies—innovations designed to support older adults—range from simple mobility aids to sophisticated smart home systems. However, research shows that successful technologies aren't those that position older people as passive recipients of care, but those that align with their identities as capable agents. When technology respects this dual identity—acknowledging real needs without undermining autonomy—it can significantly enhance functional ability .
The built environment profoundly influences functional trajectories. Urban design that incorporates walkable neighborhoods, accessible transportation, and social gathering spaces can mean the difference between isolation and engagement for older adults with mobility challenges. The World Health Organization's Age-Friendly Cities initiative recognizes that functional ability depends as much on the environments we create as on our biological capacity 8 .
Social policies either support or undermine functional ageing. When healthcare systems reimburse procedures but not functional assessments, they prioritize treatment over prevention. When retirement policies use rigid chronological age cutoffs, they disregard functional heterogeneity. When urban planning prioritizes automobile transportation, they limit mobility for those who cannot drive.
The European Union has pioneered integrated approaches through initiatives like the European Innovation Partnership on Active and Healthy Ageing, which layers policy frameworks, financial instruments, and metrics that evolve together toward supporting functional ability across the life course 1 .
The most successful strategies recognize that functional ageing is a shared responsibility—between individuals maintaining their health, technologists designing enabling solutions, and societies creating inclusive environments.
The functional ageing paradigm offers more than just improved individual outcomes—it presents a compelling alternative narrative for entire societies facing demographic change. Rather than viewing population ageing primarily as a burden or crisis, the functional perspective reveals opportunities for contribution, growth, and continued development across the life course.
The longevity dividend—the potential social and economic value of longer, healthier lives—can only be realized when extra years are matched with preserved functional ability 1 .
As the WHO emphasizes, there is no typical older person 8 . The remarkable diversity in functional ability among people of the same chronological age is both a challenge for policymakers and an opportunity.
The science-technology-society approach to functional ageing ultimately points toward a more inclusive vision: creating environments that don't merely extend life but expand possibility.
In this future, the measure of a society's success won't be how long its citizens live, but how fully they function at every age.