The National Disability Authority Act, 1999 defines "disability" to mean "a substantial restriction in the capacity of a person to participate in economic, social or cultural life on account of an enduring physical, sensory, learning, mental health or emotional impairment." Disability has traditionally been equated with physical, sensory and/or intellectual impairment. The classic 'medical model' locates disability as an individual problem, directly caused by disease, trauma or other health condition. Treatment is conceived of in terms of medical care (WHO 2002a, p.8). The 'social model' of disability originated in the disability movement in the U.K. and the U.S.A. The Union of Physically Impaired Against Segregation defined disability as
The disadvantage or restriction of activity caused by a contemporary social organisation which takes little or no account of people who have physical impairments and thus excludes them from participation in the mainstream of social activities.
(Union of Physically Impaired Against Segregation (UPIAS) 1976).
This social model distinguishes impairment, which is a condition of the body, from disability, which is a situation of social exclusion caused by the organisation of society. The model thus places the focus of change on social institutions and the environment, rather than on the individual. It also stresses the role of empowerment, participation and leadership of disabled people in effecting change. Though differences in interpretation of the social model exist, the influence of social factors on the experience of disablement has now been widely accepted, as evidenced in the WHO's International Classification of Functioning, Disability and Health (WHO 2002a). A 'post-social' model of disability that incorporates aspects of both the social model and the medical model will form the basis for the upcoming post-censal National Disability Survey.
Ageing is often equated with chronological age. Concern about population ageing, in chronological terms, has resulted in widespread debate on an impending 'demographic timebomb' and increased 'dependency ratios'. Connell and Pringle (2004) define 'dependency ratio' as "the ratio of those in the population considered to be dependent (below 15 years and above 65 years), to those considered to be of working age (15-64 years)" (p.82). Leeson (2004) identifies 5,500 economic evaluations of the costs of an ageing population, but argues that mortality and health care expenditure is increasingly linked not to chronological age, but to life style, behaviour and diet. The limitations of chronological age as a basis for social planning have been identified in international policy, where chronological age has been described as a "crude tool" for identifying needs of particular population groups (United Nations Population Fund 1998). Characterisations of the ageing population in terms of "dependency ratios" project negative images of ageing as dependency and do little to define the diverse needs of older people (See NCAOP 2005a, pp.31-32). In addition, such characterisations serve to hide the valuable contribution older people make to society. For example, grandparents provide a substantial amount of unpaid care to the 54,000 families in Ireland whose parents both work, while in 2002 over 16,000 people aged over 65 identified themselves as primary carers (Good & Fitzgerald 2005, p.25). Though statistics about demographic change have value in highlighting the changing formation of our population, it is important to distinguish chronological age as a statistical fact from the process of ageing as a complex phenomenon with physical, psychological, cultural and social aspects.
Ageing has traditionally been associated with physical and mental decline. It is conceptualised in terms of loss of faculties. Kennedy & Minkler (1998) discuss the origins of this linkage in relation to industrialisation. In the late 1800's, political, economic and other social forces resulted in a gradual devaluation and medicalisation of old age (p. 769). Critical gerontology theorists argue that old age is increasingly being conceptualised as a medical problem (Robertson 1997, p. 427). Hannah McGee claims, however, that we need to distinguish the medical conditions of older people from the prejudice and discrimination which operates through our economy and society (McGee 2005, p.30).
More recently, ageing has been conceptualised in terms of a life cycle, or life course. As Bigby states, "ageing is a process, not an event" (2004, p.19). According to a life course approach, generational categories of ageing shift over time, are embedded within culture and are shaped by structural processes of social change (Priestley 2003, p.21). The life course approach focuses on how the organisation of society creates generational categories. For example, Priestley and others have argued that both disability and ageing are produced in society through labour market exclusion (Ibid., pp. 143, 146). Both people with disabilities and older people are often excluded from work. For older people, their identity as a distinct category has been underscored by the development of pension policies that require retirement at a fixed age. Similarly, disability theorists have argued that the category of 'disabled people' has arisen out of the exclusion of people with disabilities from the adult labour market as a result of industrialisation (Oliver 1993, p.253).
It is suggested that life course categories are more useful in analysing ageing and disability than chronological categories. Bigby points out that the definition of "older person" differs between disabled and older people's services; services for people with disabilities may define persons aged 50 and over as old, whereas services for older people are often designed for people over the age of 75 (Bigby 2004, p.245). A life course approach enables analysis of the diversity of ageing experiences by examining the different trajectories of transition from adulthood to old age for different social groups.
Recent social policy statements have sought to re-define ageing in a positive way. The World Health Organisation (WHO) defines 'active ageing' as "the process of optimising opportunities for health, participation and security in order to embrace quality of life as people age" (WHO 2005). The term 'active ageing' emphasises the continuing participation of older people in the social, economic, cultural, spiritual and civic affairs of society (WHO 2002b, p.12). The WHO's policy document Active Ageing: A Policy Framework (2002) supports a life course approach to ageing, and sets out the key determinants of active ageing which are social, environmental, behavioural, economic, personal and health/social service related.
'Successful ageing' is a concept developed in part through the MacArthur Foundation study on ageing. It is also sometimes referred to as 'positive' ageing, or 'productive ageing'. The Successful Aging report defines successful ageing in terms of the ability to maintain three key behaviours or characteristics: low risk of disease and disability, high mental and physical function and active engagement with life (Rowe & Kahn 1998, p. 53). While social participation is connected with one of these factors, it can be seen that this definition is heavily reliant on physical and mental health. Kennedy & Minkler have criticised the association of successful ageing with physical health, arguing that such a linkage "not only reinforces the valuing of people primarily in economic terms, but further marginalizes groups such as caregivers and the elderly, who are already excluded from the labor force" (Kennedy & Minkler 1998, p. 772). By seeking to affirm the value of older people through a commitment to healthy ageing, policymakers may undermine the value of people with disabilities. In so doing, some ageing activists may have "traded earlier, limited views of ageing for an even more limited view of what it means to be old and disabled" (Ibid., p.769). The NCAOP has argued that older people should not be constrained by a single version of ageing, either the 'deficit' model, which sees old age as an illness without cure, or the 'heroic' model, which suggests that to age successfully you must maintain the appearance, capacities and perspectives of youth and middle age (NCAOP 2005a, p.31). When considering ageing policy it is important to ensure that frameworks promote the inclusion of all older people, whether or not they have impairments.
The Australian Institute of Health and Welfare (2000) defined dependency as "a state in which an individual is reliant on others for assistance in meeting recognised needs". Such a definition of dependency presupposes that disablement is located in the individual and that disablement necessarily leads to dependency. Morris (1999) describes how dependency, like disability, has been associated with being helpless, powerless and vulnerable. This view of dependency focuses on loss of control and leads to a biologically-based association between dependency and impairment. From this perspective, dependency is often viewed as a necessary consequence of chronological age. The focus on dependency ratios within international debates concerning the ageing population presumes that people of a certain chronological age will require substantial support. Discussion then focuses on how to increase the numbers of younger people in work to provide enough funding for long-term care (see for example, the European Commission's Green Paper "Confronting demographic change: a new solidarity between the generations", 2005). Robertson (1997) uses the phrase "apocalyptic demography" to describe "the prevailing belief ... that an increasing ageing population inevitably means increasing demands on the resources of society, including health care resources, in the face of competing interests and diminishing, or at best finite, resources" (p. 426). This view has been challenged by recent evidence which shows a decline in the proportion of older adults who report certain activity limitations (Singer & Manton 1998). So too, Manton, et al. 1997 reported statistically significant declines in chronic disability prevalence rates in the elderly United States population between 1982 and 1989. This new evidence has led to suggestions that there may be a compression of morbidity, rather than a lengthened duration of disability amongst the older population. It highlights the diversity in the dependent population and the need for more complex analyses of dependency.
Rather than dependency being equated with the need for assistance, it should be understood as the consequence of a failure to provide the means for effectively negotiating assistance. Bould, et al.'s definition of dependency is helpful in this regard, as it distinguishes dependency from loss of self-determination. Dependency is "a loss of self-determination that results from requiring the help of others but being unable to negotiate the terms of the help received" (Bould, et al. 1989).
The Independent Living Movement has sought to break the association between dependence and being able to do things for oneself. They have challenged the idea that to rely on others for physical help inevitably means a loss of choice and control. Morris (1999) argues that this is due to socially constructed unequal power relationships within care. Giving individual people with disabilities purchasing power over care through direct payment schemes fundamentally changes care relationships from those of dependence to independence (pp. 11-13).
Recently Good & Fitzgerald (2005) drew a distinction between 'necessary dependency' that is an integral part of being human, and 'social dependency' that is a product of the interaction between the individual's life situation and the structures and systems within which that individual lives. This distinction has parallels with the social model of disability as described above. Like the social model, a social conceptualisation of dependency puts the focus on society's role in producing dependency. The suggestion is that dependency can be reduced through changes in attitudes and in the physical environment. Social dependency focuses on whether society has created structures and supports that facilitate and maximise independence.
Some writers have suggested that a focus on dependence and independence unnecessarily portrays the issue of care in terms of two extremes. According to this view, modern society is rooted in a 'radical individualism' bestowed upon us from Enlightenment thinkers (Robertson 1997, p. 435). This individual actor regards interpersonal interactions in terms of the social contract and envisages him-self as a self-reliant, self-sufficient being (p. 435). But Formosa (1997) describes the reality for older people as an 'interdependent lifestyle' which involves reciprocal care between friends, neighbours and families. Robertson (1997) argues in favour of a 'moral economy of interdependence'. She suggests that "the fact that we live in community means that we are 'ipso facto' interdependent", and that this is evidenced by a modern welfare state which institutionalises reciprocity (p. 437). She argues that what is needed is a recognition that we are all interdependent. The moral economy of interdependence would allow for moral discussion on the issue of need (p. 438). It would also require that we decommodify reciprocity, acknowledging that much of what is undertaken in caring cannot be measured (p.439). This suggests that only by taking into consideration our universal interdependence can the pervasive informal labour of care be adequately understood.