One might think that successful aging would be a noncontroversial topic, one that everyone would agree is a good goal to pursue. However, considerable controversy has arisen over its definition, causes, and consequences. This controversy has been fueled in part by the fact that as more and more people enter the third age (over age sixty), concern has begun to shift from medically prolonging life to ensuring that a prolonged life is worth living. The concept itself is rather paradoxical: it combines a positive term (successful) with one usually perceived as negative (aging). How can one be ‘‘successful’’ at a process which usually means decrement and disability? The answer lies in the definitions.
The concept of successful aging, which appeared early in studies of aging, has sometimes been equated with life satisfaction or happiness, and, sometimes with good health or with longevity. A more comprehensive definition of successful aging would combine all three of these elements: longevity (without which successful aging is impossible), health (lack of disability), and happiness (life satisfaction).
M. Powell Lawton (1983) has defined ‘‘the good life’’ (in old age) as consisting of four independent dimensions:
- Behavioral competence (health, perception, motor behavior, and cognition)
- Psychological well-being (happiness, optimism, congruence between desired and attained goals)
- Perceived quality of life (subjective assessment of family, friends, activities, work, income, and housing)
- Objective environment (realities of housing, neighborhood, income, work, activities, etc.)
More recently, Rowe and Kahn have urged a distinction between usual and successful aging within the category of normal, or nonpathological, aging. They define usual aging as aging in which extrinsic factors heighten the effects of intrinsic aging processes (normal functional decrements); whereas successful aging refers to aging in which extrinsic factors counteract intrinsic aging, so that there is little or no functional loss. Successful aging thus includes three key characteristics:
- Low risk of disease and disease-related disability
- High mental and physical function
- Active engagement with life
The longevity component of successful aging has been studied through research on causes of mortality and longevity. There have been numerous studies of factors associated with mortality, and a few studies of predictors of longevity. Predictors of longevity include being female; being physically active; not smoking; having good cognitive functioning; higher than average socioeconomic status; high levels of social activity; life satisfaction, and work satisfaction; a high happiness rating; and satisfying sexual activity. In general, the predictors of longevity also predict better health (less disability). This is contrary to the popular theory that greater longevity causes greater disability.
Other studies have focused on factors associated with life satisfaction. These factors include good health, higher than average socioeconomic status, being single or married (as opposed to widowed, divorced, or separated), and high levels of social activity (especially organizational activity). Lawton found that the factors most closely correlated with feelings of well-being were health and activity level.
Usually, there is little or no relationship between life satisfaction and age, race, sex, or employment—once controls are made for health and income. The lack of relationship to age is explained by Brandstädter and Greve as being due to three interdependent processes that older persons use to maintain their life satisfaction as they grow older: assimilation (instrumental coping to attain desired goals), accommodation (changing desired goals), and immunization (filtering out threatening information). A series of analyses of studies of the causes of happiness (e.g., Okun, Stock, Haring, and Witter) also found that health (especially self-rated health), was the most potent correlate of happiness. Achieved social status variables (such as income), as well as lifestyle variables (such as social activity and housing), were modestly related to happiness.
There have been few longitudinal studies of the predictors of happiness or life satisfaction. In the Second Duke Longitudinal Study, the strongest predictors of life satisfaction were health, social activity, and sexual enjoyment. There is considerable overlap between these two sets of predictors: both longevity and satisfaction were predicted by health, higher socioeconomic status, social activity, and sexual enjoyment.
An analysis of the predictors of successful aging in the Second Duke Longitudinal Study of Aging (Palmore) defined successful aging as survival to age seventy-five and being generally happy. Multiple regression analysis found that the significant independent predictors of successful aging were secondary group activity (organizational groups and reading), work satisfaction, physical activity, physical abilities, and happiness. These findings support the activity theory of aging, in that two of the strongest explanatory predictors of successful aging were group activity and physical activity. There is probably a reciprocal causal relationship between these variables: those who remain active are more likely to be healthy and happy, and vice versa.
Avoiding disease and disability
Rowe and Kahn assert that most older people, even the very old and weak, have the capacity to increase their muscle strength, balance, walking ability, and overall aerobic power. We now know that there are many things that can prevent or ameliorate the chronic diseases common in old age, including:
- Early detection (regular medical examinations and self-examinations, combined with X-rays and laboratory tests of blood and urine)
- Healthful nutrition (low fat, high fiber, multivitamin and mineral supplements)
- Vigorous exercise (aerobic, flexibility, balance, and strength building)
- Safe driving (seat belts, observing speed limits, not using cell phones while driving)
- Safe sex (protection against AIDS and venereal disease)
- Vaccinations (against the flu, pneumonia, and tetanus)
- Avoiding obesity, tobacco, alcohol abuse, and drug abuse)
- Social support—according to David Myers, those who enjoy close relationships eat better, exercise more, and smoke and drink less; he suggests that a supportive network helps people evaluate and overcome stressful events.
Maintaining mental function
The maintenance of mental function is usually considered an essential component of successful aging. A 1999 study (Gould et al.) found that adults continue to grow new brain cells throughout life. This has encouraged a shift from the old assumption that cognitive powers inevitably decline with age to new theories that older people can bolster their learning and memory abilities, and even stave off declines. Several studies have found that the major ways to maintain mental function include:
- Continuing education and mental challenges (reading, skill games, puzzles, learning new subjects, problem solving). Laurence Katz, a professor of neurobiology at Duke University, says that his neurobic exercises help the brain not only to maintain connections between nerve cells, but also aid in developing new connections.
- Maintaining cardiovascular fitness through daily aerobic exercise (which avoids the effects of stroke and other diseases on the brain)
- Engaging in useful, satisfying work or voluntary activities (especially complex, challenging, and self-directed work)
- Memory training (concentration, memory devices, learning techniques
- Maintaining appropriate social support (getting encouragement and help when needed)
Engagement with life
According to Rowe and Kahn, there are two main aspects of active engagement (which they define as a component of successful aging): social support and productive activity. Or, as Freud put it, ‘‘love and work.’’
Social support involves giving and receiving positive information, trust, care, love, esteem, network membership, and mutual obligation. Two kinds of support are important for successful aging: socioemotional support (e.g., affection, liking, love, esteem) and instrumental support (e.g., assistance or care when one is ill, help with household chores, transportation, loans, gifts). However, it is best if the support is mutual: receiving support should be balanced by giving support, insofar as is possible.
The importance of productive activity was demonstrated in longitudinal studies of aging at Duke University (Palmore and Jeffers), which found that work satisfaction (defined broadly as any kind of useful activity) was one of the best predictors of longevity. Rowe and Kahn found three main factors that promote productive activity: health, social support, and self-efficacy. All three of these factors interact and reinforce each other. As was indicated previously, social support seems to help overcome stress and promote healthful lifestyles.
In general, most studies agree that successful aging is, for the most part, not determined by genetics (as many believe), but by lifestyle choices in diet, exercise, mental challenges, self-efficacy, and involvement with others. There is a popular saying, ‘‘If you want to live long, choose long-lived parents.’’ This saying, although humorous, oversimplifies the findings of studies of longevity among older persons. While it is true that genetics can cause inherited diseases such as sickle-cell anemia and hemophelia, these tend to take their toll early in life. If one survives to middle age, one probably has a healthy set of genes, and at that age the primary determinants of successful aging become the lifestyle, psychological, and social factors discussed above.
There are two main criticisms of the concept of successful aging: (1) it is a categorical concept rather than a continuum; and (2) it tends to blame those who do not measure up to high standards of aging. However, the view of successful aging as ‘‘categorical’’ fails to recognize that there are many shades of gray between the ideal of successful aging and failure (usual aging). No one can be perfectly successful on all dimensions of aging. Many people have some chronic illness or disability and still manage to function fairly well and remain involved. Many others are relatively healthy and functional despite having disengaged from most of life. Critics say that these people should be considered relatively successful, despite imperfections.
Regarding the second criticism, one must consider that many elders cannot measure up to the high standards of successful aging on some or all dimensions, through no fault of their own. There are accidents, genetic weaknesses, psychological blocks, ignorance, lack of resources, and other external factors that prevent successful aging in many elders. Critics say that they should not be blamed and made to feel guilty for their ‘‘failure.’’ Nevertheless, successful aging is such a positive and useful concept that it has enjoyed widespread acceptance among both professional gerontologists and nonspecialists.
Erdman B. Palmore
See also Functional Ability; Health, Social Factors; Longevity: Social Aspects; Quality of Life, Definition and Measurement; Subjective Well-Being.
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