Disability is defined by the World Health Organization (WHO) as the temporary, prolonged or permanent reduction or absence of the ability to perform certain commonplace activities or roles, sometimes referred to as activities of daily living. Examples include the loss or reduction of hearing (HEARING LOSS), seeing, speaking, walking, reaching/carrying or thinking/remembering.

Impairment is an abnormality in an organ or in the physical or mental functions of the body that produces disability. Examples include partial or complete loss of a limb; neurological conditions such as multiple sclerosis, cerebral palsy and Parkinson's disease; disease or damage to parts of the eye or ear; various forms of ARTHRITIS; and trauma that results in permanent changes to the brain or spinal cord or limbs.

Handicap refers to the social and environmental consequences of an individual's impairment. A wheelchair user is handicapped trying to move about in an environment with steps and uneven surfaces but not on smooth surfaces; a person with a mental illness may be handicapped in getting work if employers just assume he or she is not capable of holding a job, but can be successful if given a tryout.

Disability, impairment and handicap are interrelated. While an impairment may be permanent (eg, vision loss that is not correctable), a disability is often situational (eg, it only affects activities that require vision), and a handicap can be removed by altering the environment (eg, provide information in braille or audiotape format). However, there are many situations in which an impairment may cause neither a disability nor a handicap. Loss of an index finger may have no impact on the work of a teacher but a significant impact on the work of a pianist.

Prevalence of Disability

The 1991 Canadian census asked about disabilities that limit an individual in work or lifestyle activities. The subsequent 1991 Health and Activity Limitation Survey (HALS, Statistics Canada) estimated there to be 4.2 million people in Canada, or roughly 15.5%, with some form of disability that limits daily activities.

This was an increase from 3.3 million or 13% in the 1986 HALS. Unfortunately, the survey was not repeated following the 1996 census so it will remain unclear how much of the increase from 1986 to 1991 is attributable to better reporting of disability by individuals, and how much is due to an actual increase in the number of people with disabilities.

The likelihood of having a disability increases with age. In 1991, 7% of Canadians with disabilities were under 15, 22% were 15 to 54, 27% were 55 to 64, and 46% were over 65 years of age. Improvements in lifesaving medical interventions, along with increases in lifespan generally, mean that growing numbers of Canadians will experience disability for at least a few years of their lives. This knowledge has sparked considerable interest in revamping the ways in which society provides care and assistance, particularly to seniors, the fastest growing cohort of people with disabilities (see AGING).

Nature and Severity of Disability

Restrictions in mobility (walking, climbing stairs) and agility (reaching, lifting, bending) are the most common, accounting for about half of all reported disabilities. Intellectual, learning and mental health disabilities together are reported by about one-third of individuals; hearing disabilities by 25% of individuals; vision disabilities by 9%; and speaking disabilities by 8%. Some people have more than one type of disability.

Severity of disability varies with age. Mild disabilities are reported for 89% of children with disabilities, 54% of those 15 to 64, and 39% of people over 65. Severe disabilities are found in only 3% of children with disabilities, 14% of 15 to 64 year olds, and 25% of those over 65. These figures are from the 1991 HALS publication of Statistics Canada.

Accurate identification of disability remains a largely unsolved problem. The causes of disability are numerous, and the resulting degree of disability, even from the same cause, can vary widely among individuals. Methods of identification of disability also vary widely from country to country, making it difficult to understand disability as a worldwide issue. Moreover, a diagnosis or label identifying a disabling condition is often not helpful in understanding the functional limitations an individual may experience.

Some disability labels are used to determine who is or is not eligible for certain treatments or benefits. For example, the term "legally blind" (see BLINDNESS AND VISUAL IMPAIRMENT) refers only to those whose central vision is equal to or less than 20/200 in the better eye with corrective lenses (20/20 is normal vision) and to those whose peripheral vision is 20/100 or less. It is incorrect to assume that an individual who is legally blind is unable to see at all. In Canada, being legally blind may entitle the person to receive certain benefits such as bus passes at little or no cost, or to acquire assistive devices from government funded programs.

Other disability labels have been used to exclude individuals from mainstream society. Until recent years, children with intellectual (developmental) disabilities, formerly referred to as mental retardation, were kept apart from other children. Until the mid-1970s this often meant institutionalization for life. With the advent of new philosophies and education techniques, these children increasingly remained with their families but were placed in special segregated classes or schools. In the last decade progress is being made toward including them in regular schools and classes with adapted learning resources.

The identification and classification of disabilities is of interest to scientists, politicians and program designers, each of whom would use this information in different ways. Scientists could be interested in studying prevention, cure or treatment; politicians might wish to understand the size and needs of groups of people with disabilities for legislative and funding purposes; and program designers want to ensure programs will meet needs and predict increasing or decreasing demand for services over time. So far, a comprehensive and useful system of classification that is universally applicable has eluded scientists.

People with disabilities and their advocates recognize that reliable data on the number of individuals experiencing problems as a result of a disability can be useful in advocating for change. However, many are fearful of a system that labels and classifies because it tends to dehumanize and segregate whole groups of people.


People with disabilities have always been with us but they have not always been as visible as they are in Canada today. Early death and institutionalization accounted for their invisibility. Historically there has been a stigma and a degree of shame attached to disability. Some religions view disability as punishment for sin. In communal cultures, where survival depended on everyone doing his or her share, those unable to do so were left to die. Darwin's evolution theory, "survival of the fittest," led Victorian England to dabble in selective breeding of intelligent individuals in order to improve the quality of the race. Hitler is certainly best known for his attempts to create a master race, eliminating undesirable characteristics including disability.

In modern times, these attitudes have translated into negative behaviours toward people with visible disabilities who are perceived to deviate from the norm in undesirable ways. Many of us experience fear or discomfort in the presence of someone who seems so different from us and this can lead to avoidance. Ability may be overlooked or discounted, expectations lowered, and achievements disqualified. Knowing this, individuals whose disability can be hidden, like partial hearing loss or mental illness, have often gone to great lengths to be seen as "normal." Irving Goffman refers to this as "passing," but it can lead to great stress in the individual who fears discovery of his or her disability.

Conversely, certain people with disabilities may be imbued with superlative characteristics that are also inappropriate. Belief that disability makes people more understanding or forgiving, or that their ordinary achievements are superior can be just as damaging as underestimating their abilities.

The study of attitudes toward people with disabilities and how to change them has occupied social scientists for over 30 years and no definitive answer has emerged. What seems to be true is that attitudes of acceptance are fostered by ongoing contact between disabled and non-disabled individuals that is of an equal status nature - similar age, shared social activity, co-worker. The ability of the disabled person to reduce the discomfort of others by acknowledging the disability is also helpful. This means that disabled persons may have to be the initiators of contact until their differences are recognized by others as secondary, not the defining characteristics of their lives.

Greater visibility of people with disabilities in general has also had a positive impact on how they are viewed by society at large. As barriers to mobility are removed it is no longer unusual to see people in wheelchairs in public places; deaf people using sign language have appeared in television programs and advertising; famous actors and entertainers discuss their blindness or mental illness in the media. The fear so often raised by deviance from the norm is gradually eroding.

Rights and Responsibilities

Disability has been viewed by many as primarily a medical problem that rests with an individual. Diagnostic labels attached by physicians have then led to rehabilitation therapies that attempt to "fix" the person. Since most disabling conditions are permanent, by definition, this curative approach is less than satisfactory for individuals with disabilities. It frequently meant that they became reliant on government support for their basic needs, because society could not conceive of someone in a wheelchair, or deaf or blind, being capable of holding a job or living independently.

Fortunately, in the 1970s, a disability rights movement began that resembled the civil rights movement in the US in the 1950s and 1960s. Large numbers of young people with disabilities joined together to advocate for their rightful place in society. In Canada, this eventually resulted in the inclusion of "physical and mental disability" in the CHARTER OF RIGHTS AND FREEDOMS, and subsequently in provincial HUMAN RIGHTS legislation. Discrimination has not disappeared but people with disabilities now have legal recourse.

Along with legal protection from discrimination, people with disabilities have advocated for a different view of disability - that it represents difference rather than deviance. They have argued that their differences can be accommodated by altering the environment, rather than trying to change the individual.

The result has been an emphasis on removing physical barriers to public buildings, parks and recreation facilities, transportation services (both public and commercial), educational facilities and programs, information, housing and employment. Some of the changes have been accomplished through legislation (building codes, education acts, employment equity acts) and others through persuasion.

The road to change has been uneven, and some groups have benefitted more than others. Mental illness is still poorly understood by the general public, and, as a result, acceptance of people with mental illness into mainstream society is very limited. However, genuine changes are coming from the efforts of disabled people themselves.

It is no longer a question of adapting behaviour to the dominant social norms, but of challenging definitions established by those who are "normal" and demanding the right to be different, and to have that difference accommodated.