People with disabilities constitute our nation’s largest minority group, which is simultaneously the most inclusive and the most diverse. Everyone is represented: all genders, all ages, all religions, all socioeconomic levels and all ethnic backgrounds. The disability community is the only minority group that anyone can join at any time.
The language a society uses to refer to persons with disabilities shapes its beliefs and ideas about them. Words are powerful; Old, inaccurate, and inappropriate descriptors perpetuate negative stereotypes and attitudinal barriers. When we describe people by their labels of medical diagnoses, we devalue and disrespect them as individuals. In contrast, using thoughtful terminology can foster positive attitudes about persons with disabilities. One of the major improvements in communicating with and about people with disabilities is "People-First Language.” People-First Language emphasizes the person, not the disability. By placing the person first, the disability is no longer the primary, defining characteristic of an individual, but one of several aspects of the whole person. People-First Language is an objective way of acknowledging, communicating, and reporting on disabilities. It eliminates generalizations and stereotypes, by focusing on the person rather than the disability.
Our words and the meanings we attach to them create attitudes, drive social policies and laws, influence our feelings and decisions, and affect people's daily lives and more. How we use them makes a difference. People First Language puts the person before the disability, and describes what a person has, not who a person is. Using a diagnosis as a defining characteristic reflects prejudice, and also robs the person of the opportunity to define him/herself.
Excerpt taken from The Arc website: thearc.org