マイペース、マイ・スタイル！　～日本語がぺらぺらになるには～

What’s interesting to me is that “retarded” was once an accepted and professional term for a person with mental or developmental disabilities, which has now fallen victim to a phenomenon called pejoration or the “Euphemism treadmill” (a term coined by Steven Pinker). This is the process by which words for taboo or negatively associated subjects (bodily functions, disabilities, death) are born as euphemisms (more polite ways of talking about a subject) and then, gradually, start to aquire negativity from negative use, and eventually are shunned and replaced by a new euphemism.