Moron, Imbecile and Idiot- Which Hurts The Most?
Jonah Turner | April 7, 2026
Back in 1906, the modern-day American Association on Intellectual and Developmental Disabilities (AAIDD) was known as the American Association for the Study of the Feebleminded. Before that, it was the Association of Medical Officers of American Institutions for Idiotic and Feebleminded Persons. By 1933, psychiatrists realized how offensive the name could be, so the organization was renamed to the American Association for Mental Deficiency.
In 1987, members of the organization realized that the name could still be considered offensive, so they changed it to the American Association for Mental Retardation.
That name did not stick either, because eventually it became what is today, the aforementioned AAIDD; however, the act of redefining themselves from “Mental Deficiency” to “Mental Retardation” feels like a regression according to the understanding we have of language today.
A societal trend known as the Euphemism Treadmill, coined by psychologist Steven Pinker in a 1994 New York Times (NYT) opinion piece, bears much of the responsibility for this seeming regression– new, polite terms, or euphemisms, are created or adopted as acceptable substitutions for harsher, taboo or negatively associated terms. Naturally, as society evolves and language and the way it is used adapt to societal needs, words become social representations of the shifting attitudes. Communities now avoid terms they consider to be politically incorrect in 2026 that were likely once the preferred euphemism that replaced another term that came before it.
Image from the 1994 Op-Ed about the Euphemism Treadmill by the New York Times.
Illustrated by the idea of the treadmill, polite language is only consistent in that it is constantly changing.
To preface, the following offensive terms are referenced as social constructs and are as separate from the implications of their meanings as possible.
In the 20th century, the AAIDD defined mental retardation as an overarching classification to define all people with an IQ lower than 70-80 (depending on the chart defined by the researching psychologist).
IQ classification has served as the standard metric for the AAIDD’s classification system for mental processing capacity since its founding. The various classifications of IQ were built around the grouping of numbers on the common 1-200 scale, but the classifications under the average IQ range (70-80, depending on the chart) were described to the layman by comparing it to the developmental levels of children.
There are three words used for the three classifications that bring to light the inconsistency and double standard of the euphemism treadmill.
Moron: Depending on who one asks in 2026, moron is considered politically incorrect even though it is still used as an insult, and is referred to as an offensive slur that targets those of a lower developmental level, with an IQ of 50-75. In 1912, a moron was defined as “Those whose mental development is above that of an imbecile, but does not exceed that of a normal child of about twelve years.” Ouch.
Imbecile: The least common of the three, which in 2026 is often considered a more creative, lesser-used insult for acts of foolishness, with an IQ category of 25-49. In 1912, imbecile was defined as “Those whose development is higher than that of an idiot, but whose intelligence does not exceed that of a normal child of about seven years.”
Idiot: A vastly more common insult, but definitely the worst of the three, bound to an IQ category of 0-24: “Those so defective that the mental development never exceeds that of a normal child of about two years.”
All of these definitions can be found on page 7 of Edmund Burke Huey’s “Backward and Feeble-Minded Children,” published in 1912.
There seems to be heavy irony: the AAIDD-created word “moron” is too offensive to use casually because of the possible offense to those with an AAIDD classification of that degree, even though the “mental deficiency” is more minor than a classification like idiot. By AAIDD definition, idiot is a more severe insult than moron, despite the common, mirrored misconception– and yet, idiot is the household favorite.
Part of the explanation for this irony is the true etymology of the words. According to Etymonline.com, idiot is traceable to Middle English in the 14th century as a term for a simple or uneducated man. Similarly, imbecile is a word with French origins with an adjacent meaning and connotation, feeble and weak.
Moron can be traced to 1910, just before being adopted by the AAIDD, with the exact same definition as Huey’s listed above. It was supposedly first used as an insult in print in 1918, and later dropped as a medical term because of the implicit overlap (AAIDD has historically played a cat-and-mouse game with the euphemism treadmill since its founding).
That being said, moron is still accepted as the more distasteful insult in 2026, despite this contradiction. The unique way “moron” was termed and the singular way in which it was used by the AAIDD, its implication is much clearer when used as an insult, and prone to scattershot offense because of that singularity.
“Imbecile” and “idiot” have had more diverse usages before and after the historic AAIDD classification in 1912, and likely nobody will start saying that “idiot” is politically incorrect. Regardless, one unknowingly relies on the euphemism treadmill to determine what is politically correct, and due to the nature of informal social trends, the treadmill then relies on one and all others.
Why accept the decision of the treadmill without understanding why the treadmill came to that decision? The analysis above gives an explanation for a euphemism mandated by the greater community that has been determined as “politically correct.” Participating in the treadmill is one of the best ways to bring power to the individual through knowledge and connection, and investigating the context is incredibly important to the perpetuation of the cycle.
If one has the facilities to make an honest attempt at understanding why society decides what is and is not correct to say, it is best for them to do so, if not for their own understanding, for others’.