The last century has witnessed substantial increases in life expectancy at birth, significant medical advances, and increasing health and social care expenditure. These changes have collectively encouraged international interest in the promotion of healthier old age and how to age “successfully”. The idea of successful ageing has been the subject of investigations for a variety of academic disciplines for more than 3 decades. Earlier use of the term ‘successful ageing’ has been found in the research reports of social scientists in the 1960s and 1970s (Havighurst, 1963; Williams and Wirths, 1965). While the 1980s and early 1990s had psychologists and behavioural scientists studying successful ageing (Ryff, 1982), more recent work shows an interest from physicians and health service researchers as well (Rowe and Kahn, 1998).
The concept has gained increased attention because of a combination of demographic advances and social forces (Phelan and Larson, 2002). Individuals born between 1946 and 1965 have more chances of surviving till an old age with a life expectancy of an additional 16 to 20 years (Hoyert, Kochanek, and Murphy, 1999). Moreover, analyses conducted on longitudinal data report that not only will people live longer, people are healthier and more active than before and that disability rates and institutionalization will continue to decrease in the near future (Manton, Corder, and Stallard, 1993 cited in Phelan and Larson, 2002). Lastly, older adults are more highly educated than previous generations and are more interested in health related matters (FIFARS, 2000).
This paper sets out to present definitions of successful ageing put forward by a variety of research initiatives and evaluates the concept of successful ageing. It intends to simply identify and present in a highly summarized manner, the many definitions of successful ageing that have been theorized over the past 30 to 40 years. Although emphasis is placed on psychological research, it is imperative to briefly consider biomedical research as well. It will critically evaluate theories from psychological research and assess their validity and rationale. In addition, it will offer a justification for exploring the public’s definition(s) (mainly older people) of successful ageing and will conclude by questions and potential future work in the area.
Biomedical theories
Biomedical theories from the literature reviewed define successful ageing mainly in terms of the optimisation of life expectancy while reducing physical and mental degeneration and disability. They specifically discuss: “the absence of chronic disease and of risk factors for disease; good health; and high levels of independent physical functioning, performance mobility, and cognitive functioning” (Bowling and Dieppe, 2005; p. 1549). Some key biomedical studies of successful ageing (part of the MacArthur Studies of Successful Ageing) have founded the basis of biomedical research on the topic (see Seeman et al., 1994) where there have been dichotomous explorations of the elderly sick and the elderly normal population. However, the separation of people into “diseased” and “normal” does not explicitly acknowledge the amount of heterogeneity within these groups.
To accomplish this Rowe and Kahn (1987 cited in Bowling and Dieppe, 2005) distinguished between “usual” ageing (normal decline in physical, social, and cognitive functioning with age, increased by extrinsic factors) and “successful” ageing in which functional loss is lessened (negligible or no age related decrement in physiological and cognitive functioning, with external factors playing a neutral or positive role). They suggested that the three components of successful ageing are: absence or avoidance of disease, maintenance of physical and cognitive functioning, and active engagement with life (including sustained autonomy and social support) (Rowe and Kahn, 1987 cited in Ford et al. 2000).
Their model is possibly the most widely used approach after which there has been a remarkable proliferation of studies by biologically, psychologically and sociologically oriented investigators, each with a different slant on successful ageing. Another predominantly biological definition is illustrated by the Alameda County studies of healthy or successful ageing which was defined as the top 20% on a scale of physical functioning, or “needing no assistance nor having difficulty in any of 13 activity/mobility measures plus little or no difficulty on five physical performance measures” (Guralnik and Kaplan, 1989, p.704; also see Seeman et al., 1994 for performance based measure of successful ageing). While the biomedical model specifically focuses on absence of disease and the maintenance of physical and mental functioning as chief characteristics of ageing successfully, social psychological models emphasise lift satisfaction, social participation and functioning, and psychological resources including personal growth Bowling and Dieppe, 2005).