simple language version (link)
Why the r-word is a slur and isn't comparable to words like "idiot"
I just got an uninformed comment on a recent ask saying "the r-word isn't a slur" with a link to an article - this is it - it is someone's personal piece, it isn't based in fact and makes claims that the special olympics doesn't explain how the r-word "is any more hurtful or bullying than 'intellectually disabled'." - so I will also be explaining those differences here.
The R-word Directly Refers To Those With IDDs
The R-word has been used in medical texts into the 2000s in reference to Intellectual and Developmental Disabilities. It lacks the degree of separation from those with IDDs that much more juvenile insults such as "idiot, moron, and stupid" would hold. In short, the R-word as a slur has direct references to those with Intellectual and Developmental Disabilities.
With That Established, What Differentiates Calling Someone The R-Word Compared To Calling Them Intellectually Disabled?
The simple answer is both evolution of language, and context. In the US during the 2010s, medical texts evolved from using the r word as a term, into using "Intellectual Disability", the reasoning behind this is that the R-word was taken away from its medical usage into the hands of non Intellectually Disabled individuals to be used as an insult against those with Intellectual Disabilities. Due to the context of the R-word being turned derogatory to directly reference those with Intellectual Disabilities, the term's usage in medical texts evolved to have a word that was not being used to insult people. This doesn't mean that "Intellectual Disabled" cannot and has not been used in derogatory manners, it just means that it lacks the derogatory background of the R-word.
A Brief History of The R-word
The R-word means "to hinder, delay, slow", now in the previous point I mentioned how evolution of language led to the removal or the R-word from medical texts. In the 19th-20th centuries, words like "imbecile, moron, idiot" were used professionally in medical texts both for those with IDDs and low intelligence; however, these words would in these early years also be used derogatorily, thus the R-word would be adopted. Now, as mentioned with the previous point, the R-word would turn derogatory, and with its specific ties to being used for those with IDDs, it would be replaced with Intellectual Disability. Even if the R-word was used less derogatively, it would have deeply rooted ties to psychiatric practices within the 20th century, practices that were often abusive, degrading, and/or prejudiced, adding onto the word being used to harm rather than help. Disabled is more neutral than the R-word, it lacks the abusive and derogatory ties the R-word has, again, this isn't to say that disabled as a term cannot and has not been used offensively, but it lacks the very deeply ingrained ableism within the R-word.
Sources: https://www.specialolympics.org/stories/impact/why-the-r-word-is-the-r-slur, https://thearc.org/blog/the-r-word-why-language-matters-and-how-we-can-do-better/, https://www.npr.org/2026/04/29/nx-s1-5802941/the-worrisome-return-of-the-r-word, https://www.federalregister.gov/documents/2013/08/01/2013-18552/change-in-terminology-mental-retardation-to-intellectual-disability, https://www.aadmd.org/r-word-statement, https://arcmorris.org/the-r-word