Mental Retardation -- Political Correctness
State and local agencies in Ohio that work with those suffering from "mentally retardation" seem to be worried about the impact that language might have on perceptions of their clients and those who haven't changed the name to some permutation of "developmental disability" will soon vote on doing so. The older term reflects a time when clearly identifying persons was the only consideration in coming up with language. But now we must consider what I have called the "significance" of a term, as well as its literal meaning in my blog on "The Meaning of Meaning."
One difficulty of the adjective "mentally retarded" and the noun form "mental retardation" is that they implicate some force acting on them that is holding them back. Some clear cases of terms that have this meaning and significance would be "we retarded the growth of invasive plants by ..." or "we retarded the destructive effects of acid rain on stone statues by ..." In the case of mental retardation there is no force acting on those afflicted with this problem that holds them back. They appear to have some condition that is genetic or caused by poor nutrition or an injury or whatever might cause mental disabilities. The term "mental disability" is therefore more accurate than "mental retardation." That is reason enough to change the term.
Notice that if one takes the term "mental retardation" seriously one would do research on the problem by looking at causes of retardation and make efforts to lessen the forces that are doing the retarding. So, there could be a cure for this by lessening or stopping the effects of these forces. In the case of "mental disability" the focus of research would be on efforts to assist those afflicted to learn. Moreover, this more accurate term suggests that one should also focus on research on types of disabilities and this could lead to differential means of dealing with their disabilities.
I have no expertise in this field so please take my comments to apply just to what the language suggests.