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Any physical, mental, sensory, or psychological impairment or deficiency resulting in the lack, loss, or substantial reduction of the ability to perform some normal function.

In the United States, the term disability is legally defined in the Rehabilitation Act (PL 93-112; 29 U.S.C. 794) Amendments of 1974 and the Americans with Disabilities Act (PL 101-336; 42 U.S.C. 12101) of 1990 as a physical or mental impairment that substantially limits one or more of the major life activities of an individual. Disabilities may be caused by congenital, traumatic, pathological, or other factors, and vary widely in severity. They may be temporary or permanent, correctable or irreversible. Physical disabilities include blindness, deafness, deformity, muscular and nervous disorders, paralysis, and loss of limbs. Paralysis is frequently caused by injuries to the spinal cord, with the extent of paralysis depending on the portion of the spine that is injured. Congenital disabilities include spina bifida, cystic fibrosis, and muscular dystrophy. Other causes of disabilities include cerebral hemorrhage, arthritis and other bone diseases, amputation, severe pulmonary or cardiac disease, nerve diseases, and the natural process of aging. Mental impairments are of two types: mental illness and mental retardation. Approximately 35 million people in the United States are disabled.

Professionals including physicians, physical and occupational therapists, social workers, and psychologists assist disabled persons in the rehabilitation process, helping them function at the highest possible physical, vocational, and social levels. Specialists in rehabilitation medicine, sometimes referred to as physiatrists, diagnose patients and plan individual treatment programs for the management of pain and disabilities resulting from musculoskeletal injuries. People with hearing or vision loss require special education, including instruction in lip reading, sign language, or Braille. Physical rehabilitation for individuals with musculoskeletal disabilities includes passive exercise of affected limbs and active exercise for parts of the body that are not affected. Occupational training, including counseling, helps persons whose disabilities make it necessary for them to find new jobs or careers. Rehabilitation also involves the services of speech pathologists, recreational therapists, home planning consultants, orthotists and prosthetists, driver educators, and dieticians.

Recent technological advances—especially those involving computer-aided devices—have aided immeasurably in mainstreaming the disabled into many areas of society. These include voice-recognition aids for the paralyzed; optical character-recognition devices for the blind; sip-and-puff air tubes that enable quadriplegics to type and control wheelchair movements with their mouths; and computerized electronic grids that translate eye movements into speech. In addition to access, mobility for the disabled has become an area of concern. The American Automobile Association (AAA) estimates that there are 500,000 licensed drivers in the United States with significant physical impairments and another 1.5 million with lesser disabilities. AAA auto clubs throughout the country are working to improve the mobility of disabled drivers and travelers through improved driver education for those with impairments and improved facilities for the handicapped traveler, including motorist rest areas on the highway.

Public attitudes toward the disabled have changed. Since the 1970s, advocates for the disabled have won passage of numerous laws on the federal, state, and local levels aimed at making education, employment, and public accommodation more accessible through the elimination of physical barriers to access, as well as affirmative action in the hiring and professional advancement of disabled people. Whereas many people with disabilities were formerly confined to their homes or to institutions, the current trend is geared toward reintegrating disabled persons into the community in ways that enable them the greatest possible amount of independence in both their living arrangements and their jobs. Wheelchair access at building entrances, curbs, and public restrooms has been greatly expanded and mandated by law. Braille signs are standard in public areas such as elevators.

Two major pieces of federal legislation have protected the rights of the disabled: a 1975 law guaranteeing

Source: Centers for Disease Control, U.S. Department of Health and Human Services.

Condition Number (thousands) Percent
Learning disability 1435 29.5%
Speech problems 634 13.1%
Mental retardation 331 6.8%
Asthma 311 6.4%
Mental or emotional problem or disorder 305 6.3%
Blindness or vision problem 144 3.0%
Cerebral palsy 129 2.7%
Epilepsy or seizure disorder 128 2.6%
Impairment deformity of back, side, foot, or leg 121 2.5%
Deafness or serious trouble hearing 116 2.4%
Tonsilitis or repeated ear infections 80 1.6%
Hay fever or other respiratory allergies 76 1.6%
Missing legs, feet, toes, arms, hands, or fingers 70 1.4%
Autism 48 1.0%
Drug or alcohol problem or disorder 48 1.0%
Head or spinal cord injury 45 0.9%
Heart trouble 44 0.9%
Impairment deformity of finger, hand, or arm 27 0.6%
Cancer 26 0.5%
Diabetes 14 0.3%
Other 653 13.4%
Total 4858 100%

disabled children a right to public education in the least restrictive setting possible and the 1990 Americans with Disabilities Act (ADA), which extends comprehensive civil rights protection in employment and access to public areas. Title I of the ADA, which prohibits discrimination by private employers on the basis of disability, is intended to ensure that the same performance standards and job requirements are applied to disabled persons as to persons who are not. In cases where functional limitations may interfere with job performance, employers are required to take any necessary steps to accommodate reasonably the needs of a disabled person, including adjustments to the work environment or to the way in which the job is customarily performed. The ADA also contains provisions ensuring nondiscrimination in state and local government services (Title II) and nondiscrimination in public accommodations and commercial facilities (Title III).

Further Reading

Davis, Lennard J. Enforcing Normalcy: Disability, Deafness, and the Body. New York: Verso, 1995.

Additional topics

Psychology EncyclopediaPsychological Dictionary: Kenneth John William Craik Biography to Jami (Mulla Nuruddin ʼAbdurrahman ibn-Ahmad Biography