Retard

Retard (pronounced ri-tahrd and ree-tahrd (depending on definition))

(1) To make slow; delay the development or progress of (an action, process etc); hinder or impede (pronounced ri-tahrd).

(2) To be delayed (pronounced ri-tahrd).

(3) a slowing down, diminution, or hindrance, as in a machine (pronounced ri-tahrd).

(4) A contemptuous term of US origin (as a clipping of “mental retardation”) used to refer to a person who is cognitively impaired (now disparaging & offensive slang) (pronounced ree-tahrd).

(5) A person who is stupid, obtuse, or ineffective in some way (now disparaging & offensive slang) (pronounced ree-tahrd).

(6) In the tuning and maintenance of internal combustion engines, an adjustment made in the setting of the distributor so the spark for ignition in each combustion chamber is generated later in the cycle; the opposite procedure is “to advance” (pronounced ri-tahrd).

(7) In physics, as retarded, designating a parameter of an electromagnetic field which is adjusted to account for the finite speed of radiation (pronounced ri-tahr-did).

1480–1490: From the Old French retarder, from the Latin retardāre (to delay, protract), the construct being re- + tardāre (to loiter, to make slow; to be slow), from tardus (slow, sluggish, late, lingering; dull, stupid, slow-witted) (of unknown origin but one etymologist suggests it may have some relationship to the Etruscan), from which English gained tardy (late to arrive; slow in action).  The re- prefix is from the Middle English re-, from the circa 1200 Old French re-, from the Latin re- & red- (back; anew; again; against), from the primitive Indo-European wre & wret- (again), a metathetic alteration of wert- (to turn).  It displaced the native English ed- & eft-.  A hyphen is not normally included in words formed using this prefix, except when the absence of a hyphen would (1) make the meaning unclear, (2) when the word with which the prefix is combined begins with a capital letter, (3) when the word with which the is combined with begins with another “re”, (4) when the word with which the prefix is combined with begins with “e”, (5) when the word formed is identical in form to another word in which re- does not have any of the senses listed above.  As late as the early twentieth century, the dieresis was sometimes used instead of a hyphen (eg reemerge) but this is now rare except when demanded for historic authenticity or if there’s an attempt deliberately to affect the archaic.  Re- may (and has) been applied to almost any verb and previously irregular constructions appear regularly in informal use; the exception is all forms of “be” and the modal verbs (can, should etc).  Although it seems certain the origin of the Latin re- is the primitive Indo-European wre & wret- (which has a parallel in Umbrian re-), beyond that it’s uncertain and while it seems always to have conveyed the general sense of "back" or "backwards", there were instances where the precise was unclear and the prolific productivity in Classical Latin tended make things obscure.

Retard is a noun & verb (used with and without object), retardation is a noun, retarded & retardative are adjectives, retarding is a verb and retardingly an adverb.  The (now proscribed except in historic reference) noun plural was retards; retardings remaining acceptable when used in science and engineering.  Words related in meaning in these later contexts include choke off, crimp, decelerate, hamper, handicap, impede, lessen, arrest, baffle, balk, bog, brake, check, choke, clog, dawdle, decrease, defer, delay & detain.

The general sense of “delayed; delayed in development, hindered; impeded” dates from the seventeenth century and in the nineteenth was absorbed into the early technical language of psychology (having mental retardation; mentally deficient or underdeveloped) as a clipping of “mentally retarded”.  Later it was part of the formalized system of classification of intelligence, a retard defined as having an IQ below 70.  From the jargon of the profession it was picked up in twentieth century US colloquial use to describe (1) those then defined as mentally retarded, (2) those thought stupid and (3) a derogatory term to be applied as wished.  From the 1980s it came to be regarded as offensive, use disapproved of in polite society.

President John Kennedy (JFK, 1917–1963; US president 1961-1963) addressing the thirteenth annual convention luncheon of the National Association for Retarded Children (NARC). Mayflower Hotel, Washington DC, 24 October 1963.

The names used by the NARC are interesting in that it wasn’t until the 1990s that the word “retard” was removed.  The organization was called the National Association for Retarded Children (1953-1973), the National Association for Retarded Citizens (1973-1981) & the Association for Retarded Citizens of the United States (1981-1992) before assuming the name Arc of the United States in 1992.  While hardly illustrative of the euphemism treadmill familiar elsewhere, it does hint at the difficulties changes in the social acceptability of words can cause institutions with a corporate history or identity vested in a brand name.  The National Association for the Advancement of Colored People (NAACP), formed in 1909, retained the name even after “colored people” had been declared an unacceptable form and replaced by “people of color”, because the brand NAACP was thought too valuable to alter.  However, acronyms and abbreviations can continue even if divorced from their historic connections.  The oil company British Petroleum, in filings with the various regulatory agencies with which it deals, explained that it now positions itself as “an energy company” and expected to remain trading as BP, even if the day came when it no longer dealt with fossil fuels or petro-chemicals.

Retard is an interesting example of a word in English, the use of which is socially proscribed in one historical context (human intelligence) but still acceptable in other adaptations (engineering & physics).  In this it differs from other words which began as something uncontroversial and perhaps merely descriptive but which, for associative reasons, became “loaded terms” and socially (and even legislatively) proscribed, including, the other “n-word” (negro) which as late as the 1960s was socially respectable but now, even for historic purposes (such as the description of the specific stream of music once called the “negro spiritual” or the “negro league” in baseball) should probably be replaced with an uncontroversial substitute unless use is deemed essential by virtue of the context of use.  The conventions of use may yet evolve to the point reached with the original n-word word whereby it can in certain circumstances be acceptable for it to appear in print but which may never be spoken (unless by (at least some) persons of color).       

In less globalized times, the loading could be geographically (and thus circumstantially) specific; as late as the early 1980s, the television network in Australia which held the broadcast rights to international cricket could include in their televised promotions for a series involving teams from the West Indies, Pakistan & Australia a jingle with the phrase “the Windies, the Pakis, the Aussies”.  Although all three were ostensibly affectionate diminutives of the country names and thus neutral, linguistic equivalents, “Paki” in the United Kingdom had by the 1960s come to be regarded as an offensive, ethnic slur referencing either (1) an actual Pakistani, (2) a person of Pakistani descent, (3) anyone whose origins were perceived to be South Asian or even (4) any person of color (Africans, Arabs et al).  Actually, structural linguistic equivalency is never of necessity any sort of guide to what a word has come to denote, “Chinaman” thought pejorative while “Englishman” is not.

Definitely not a word for the twenty-first century unless one is a mechanic.  

Paki acquired the offensive connotations in the 1960s from a pattern of use in the UK, reinforced by the Fleet Street (and regional) tabloids which used the word to refer to subjects of former colonies, with no attempt to disguise that it was being done in a derogatory and racist manner.  Use persists in certain sections of the community although the popular press has been forced to adopt an uncharacteristic subtlety when making their point about people of color.  Interestingly, like some other disparaging slurs (n-word, slut), there has been noted a trend of reclamation, an adoption by second and third-generation youth of Pakistani extraction to claim exclusive use of the term, excluding all outsiders, even Indians, Bangladeshis and others at whom it was originally and offensively directed.

No such phenomenon appears to have happened with “retard”, presumably because it was not a word which (in the context of human intelligence or behavior) never had any history of enjoying a neutrality of meaning, either by definition or inference always being in the negative.  Despite that, when the medical profession introduced retard, retarded & retardation to their system of classifications, genuinely it was an attempt to de-stigmatize those once labeled idiots, imbeciles & morons, the early twentieth century classifications being:

Idiots: Those so defective that the mental development never exceeds that or a normal child of about two years.

Imbeciles: 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.

Morons: Those whose mental development is above that of an imbecile, but does not exceed that of a normal child of about twelve years.

Retard was used in relation to developmental delay in 1895 and was introduced as an alternative to idiot, moron, and imbecile because at the time it wasn’t derogatory, being a familiar technical term from engineering and mathematics but the associative connection meant that it soon became an frequently heard insult.  Indeed, following the example of the n-word, there is in the United States much lobbying by interested groups socially to construct retard as “the r-word” and render its use just as unacceptable.

US legislation in 2010 required the terms "mental retardation" and" mentally retarded" be removed from federal records and replaced with "intellectual disability" and "individual with an intellectual disability", a change reflected in the publication in 2013 of the fifth edition of the American Psychiatric Association’s (APA) Diagnostic and Statistical Manual of Mental Disorders (DSM-5).  The US National Institutes of Health, which took several years to scrub “retarded” and related terms from their archival material, recommend “intellectually and developmentally disabled”, the acronym IDD being one which rolls not easily from the tongue and is therefore less susceptible to entering the vernacular as an insult.  Other organizations focused on specific conditions have also made suggestions but constructions such as “differently-abled” do seem likely to attract derision and be applied as insults, as happened with “special”.

Ignition timing: Advancing and retarding the ignition

Intake, compression, power, exhaust: the four-stroke cycle.

In a four-stroke, internal combustion engine, the ignition timing is measured in degrees of a crankshaft rotation before top dead centre (BTDC).  To ensure the power stroke is at this point achieved, the spark plugs need to fire at the right time and this is achieved by advancing or retarding the timing of the engine.  Advancing the timing means the spark plugs fire earlier in the compression stroke, further from the TDC, meaning the fuel/air mixture in the combustion chamber doesn’t burn immediately.  The primary advantage in advancing the timing of ignition is an increase in top-end horsepower at the expense of some low end response.  Retarding the ignition causes the spark plug to fire later in the compression stroke which can reduce engine detonation, which is combustion inside the cylinders after the spark plug fires, commonly referred to as “engine knocking”.  In the early days of emission control systems, retardation was usually part of the process.  In the special (although now quite common) case of engines which use forced aspiration (by turbocharging or supercharging), retarding can be beneficial because it adjusts for the increased pressure, compensating for the denser fuel/air mixtures.

Treadmill

Treadmill (pronounced tred-mil)

(1) A device for producing rotary motion by the weight of people or animals, treading on a succession of moving steps or a belt that forms a kind of continuous path, as around the periphery of a pair of horizontal cylinders (also called a treadwheel (archaic)).

(2) An exercise machine that allows the user to walk or run in place, usually on a continuous moving belt.

(3) Figuratively, a process or situation in which continued effort leads to or is required for remaining at a particular state or level without moving ahead; any monotonous, wearisome routine in which there is little or no satisfactory progress.

(4) By extension, anything repetitive and unending.

(5) In molecular biology, as treadmilling, the apparent locomotion of certain cellular filaments by adding protein subunits at one end, and removing them at the other, a phenomenon observed in many cellular cytoskeletal filaments.

1822: The construct was tread + mill.  Tread was from the Middle English tred, from treden (to tread), from the Old English tredan, from the Proto-West Germanic tredan, from the Proto-Germanic trudaną.  Mill was from the Middle English mylne & mille, from the Old English mylen, from the Proto-West Germanic mulīnu (mill), from the Late Latin molīna, molīnum & molīnus (mill), from the Latin verb molō (grind, mill), related to the Proto-Germanic muljaną (to crush, grind (related to the later English millstone).  Although speculative, some etymologists have suggested a relationship with the surname Milne, based on an associative link with the profession of some sort of milling.  The synonyms for the physical devices have variously included mill, stepper & everlasting staircase, and in the figurative sense, chore, drudgery, groove, labor, pace, rote, routine, rut, sweat, task, toil, travail & moil.  Treadmill is a noun, treadmilling is a noun & verb, treadmilled is a verb (the forms treadmillish & treadmillesque are both non-standard); the noun plural is plural treadmills.

Depiction of penal treadmill (the wheel).

Treadmills originated as a means of translating human energy into mechanical action to be applied to tasks such as moving water or air, grinding grain or making more efficient processes like the kneading of dough.  All such devices had since the mid sixteenth century tended to be known as treadwheels and the name treadmill wasn’t widely adopted until 1822 when a machine, invented by the son of a miller and used in English jails since 1818, was introduced into the US prison system, the intention in both places being to occupy the prisoners (on the basis of the theory that “the Devil makes work for idle hands”) and harness the energy produced for some useful purpose (although it’s unclear to what extent the devices were ever used a power source).  Designed ultimately to accommodate a dozen-odd men at a time, penal treadmills were rotating cylinders with steps built into the external surface, the prisoners essentially “walking uphill” for up to 4000 metres (14,000 feet) per day.  In prison slang the treadmills became known as “the wheel” and they were widely used in England until a decline in the late nineteenth century before use was discontinued in 1902; In the US, they were rare and extinct by mid-century, prison administrations preferring to apply the labor of inmates directly to some productive purpose.  The penal treadmill (the wheel) is best remembered as being one of the punishments to which Oscar Wilde (1854-1900) was subjected during some of the two-year sentence he received after being convicted of gross indecency.

Lindsay Lohan on treadmill, Planet Fitness Super Bowl commercial, 2022.

The figurative senses allude to the way running on a treadmill requires continued effort and motion in order to remain in the same place and it’s used to refer either to one’s continued application to a specific task without making discernible progress towards the goal or the general idea of being “stuck in a rut”, leading a repetitive existence.  The idea for the familiar modern device dates from the early twentieth century and in medicine, sports and the military, variations emerged as required but by the 1970s, they became a standard piece of gym equipment and have become increasingly elaborate, linked to diagnostic and monitoring sensors and even the generation of electricity, some commercial operations granting users credits against the charges for use.

The term "euphemism treadmill" was coined by Harvard professor and psycholinguist Steven Pinker (b 1954) to describe the process by which euphemisms become as emotionally or politically loaded as the words supplanted.  It was the same idea as “euphemism cycle” which University of Oregon linguist Sharon Henderson Taylor had mentioned as long ago as 1974 but more exact in that the process is lineal rather the cyclical; once cancelled, euphemisms seem forever doomed.  Linguists call this the move from euphemism to dysphemism and while it’s impossible to know how long this has existed as a social phenomenon, the implications differ greatly between (1) purely oral cultures, (2) one where written or other records exist and (3) the digital era.  It’s now not uncommon for words individuals used decades earlier (at a time when use was either common or at least tolerated) to be produced so an understanding of historical context matters.  The word retard for example was once thought neutral and inoffensive compared with the earlier terms (idiot, imbecile & moron) which had migrated from clinical use to become slurs used as general-purpose insults against anyone.  Retard suffered the same fate and it may be the currently acceptable terminology (intellectual disability, individual with an intellectual disability & intellectually and developmentally disabled) will undergo the same process although none roll of the tongue as easily as retard and IDD is not effortless so they may endure as neutral.  The solution, Pinker pointed out, was that people should be educated to "think differently" about the subject, substituting euphemisms when progress inevitably from sanitized to slurs just kicks the can down the road. 

Structurally though, the process can be seen as inevitable because it’s associative, a product of the interplay between a descriptor and that it denotes.  Gay (a word with a centuries-long history in sexual politics) emerged in the late twentieth century as the preferred term to replace all the slurs referring to homosexuals, recommended by many even as preferable to homosexual which, despite being a neutral descriptive formation, had come to be regarded by many as a slur or term of derision.  Of course, being associative, gay soon came also to be used as a slur (and as a synonym for strange, weird, un-cool or queer (in its more traditional sense)) though the negative application is now socially proscribed so gay in its modern sense may survive.  So, the change of a descriptor doesn’t necessarily change attitudes.  Just because gay became preferred to homosexual didn’t mean homophobia vanished although, interestingly, although there’s a record of the word gayphobia from as early as the 1990s, it never caught on.

Of interest too is the succession of terms which replaced the infamous N-word.  Negro (which probably already is N-word 2.0 except in historic references) was in the 1960s used in the sense of something purely descriptive by mainstream figures such as John Kennedy (1917-1963; US president 1961-1963) and civil rights activist Martin Luther King (1929-1968) but it too came to be regarded as slur and was replaced by black.  Negro did though have an interesting history.  When first used in print in English in the mid-sixteenth century it was nearly always capitalized, the uncapitalized use beginning to appear in the late eighteenth century and becoming the standard form in twentieth although there were activists who insisted an initial capital was justified as a mark of respect, despite this being etymologically dubious.  It’s now rare because it carries connotations of earlier discrimination although remains acceptable in context, such as when used by the National Association for the Advancement of Colored People (NAACP).

The mater of capitalization had also affected the use of black, some activists claiming its should be capitalized whereas white should not and that too is a purely political argument given the word initially gained currency because it was thought white’s linguistic equivalent.  In many ways that was true but it was controversial because, as used, it wasn’t exactly synonymous with Negro which is why the more precise African American became popular in the 1980s, again for reasons of seeking social equivalence (Polish-Americans, Italian-Americans, Irish-Americans et al).  Black, in practice, is often used to refer to dark-skinned people whether or not of African descent and for this reason it became unfashionable.  Other sub-sets have also moved in their own direction, the Fox News audience now preferring “the 13%”.

The distinction between colored people and people of color puzzles some but is entirely due to the historical association of colored and colored people with racism both subtle and overt.  People of color is a construction without the baggage and to date has generally be used to assert identity or in a celebratory sense and technically it’s a synonym for non-white because all those not white can so self-classify.  However, language evolves and there’s no guarantee people of color won’t emerge as a slur.  So, it can be a linguistic minefield and while the general principle is that people should be described as they wish to be described (or described not at all), at least for now, people of color seems safe.

Lindsay Lohan on treadmill, Planet Fitness Super Bowl Commercial, 2022.

Idiot

Idiot (pronounced id-ee-uht)

(1) In informal use (1) a foolish or senseless person (derogatory) or (2) an affectionate expression of disapprobation or disagreement.

(2) In medicine & psychology, a person of the lowest order in the former classification of intellectual disability (a mental age of less than three years old and an IQ (intelligence quotient) lower than 25; no longer in technical use; considered now generally offensive unless used affectionately.

1250–1300: From the Middle English idiote & ydiote, from the twelfth century Old French idiote (later idiot) (uneducated or ignorant person), from the Late Latin idiōta (an ignorant person), from the Ancient Greek ἰδιώτης (idiṓtēs) (private person, layman, person lacking skill or expertise; an ignoramus (as opposed to a writer, soldier or skilled workman), the construct being idiō- (a lengthened variant of idio-, perhaps by analogy with stratiōtēs (professional soldier) derived from stratiá (army)) + -tēs (the agent noun suffix).  The Ancient Greek ἴδιος (ídios) meant " one's own, pertaining to oneself, private" and was a doublet of idiota.  Dialectical variations in English and Irish included eejit, idjit & idget.  The plural is idiots.  English offers a rich array of alternatives to idiot: fool, moron, nitwit, twit, blockhead, bonehead, cretin, dimwit, dork, dumbbell, dunce, ignoramus, imbecile, muttonhead, nincompoop, ninny, pinhead, simpleton, clodpoll, jerk, half-wit; dolt, dunce & numskull.

Use of the word "idiot" in headlines can hurt feelings.

The original meaning was “a person so mentally deficient as to be incapable of ordinary reasoning;" but this in Middle English later in the fourteenth century extended to "a simple man, uneducated person, layman".  A meaning shift had also happened in Latin, the classical form meaning “an ordinary person, layman; outsider" whereas in the Late Latin it conveyed the sense of "an uneducated or ignorant person".  This mirrored what happened with the Greek idiotes which meant literally "a private person" (ie a layman, someone uninvolved in public affairs) but came to be applied patronizingly to suggest someone "ignorant and uneducated".  In plural, the Greek word could mean "one's own countrymen."  In medieval English common law, the formalized distinction was between an idiot (one who has been without reasoning or understanding from birth) and a lunatic (who became that way later in life), and the difference could be important in determining the responsibility and punishment for crimes committed.  The idiot savant first appeared in medical literature in 1870; idiot box was first used to describe television in 1959 and, given that broadcasting had begun in the 1930s, it’s surprising it took that long to work that out; idiot light to describe the dashboard warning lights in cars is attested from 1961, a reference to drivers so lacking in mechanical sympathy not to notice indications of problems or bother to scan gauges.

The adjective idiotic was from 1713, following the Classical Latin idioticus and the Ancient Greek idiotikos; idiotical is from 1640s; the noun idiocy (state of being an idiot) is from the 1520s, from idiot on the model of prophecy etc and the early alternatives included idiotacy (1580s), idiotry (1590s).  Until well into the twentieth century, blithering was one of the more popular adjectives applied to idiot, the form dating from 1880, the present-participle adjective from the verb blither (to talk nonsense).  A handy adaptation of idiot was the in-joke among IT staff who sometimes classify problems reported by users as ID10T errors.

Comrade Lenin agitprop.

The term useful idiot is from political science and so associated with Vladimir Lenin (Vladimir Ilyich Ulyanov (1870–1924; first leader of Soviet Russia 1917-1922 & USSR 1922-1924) that it's attributed to him but there's no evidence he ever spoke or wrote the words.  It became popular during the Cold War to describe pro-communist intellectuals and apologists in the West, the (probably retrospective) association with Lenin probably because had the useful idiots actually assisted achieving a communist revolution there, their usefulness outlived, he'd probably have had them all shot.  Although it took many Western intellectuals decades to recant (some never quite managed) their support for the Soviet Union, the watershed was probably Comrade Khrushchev's (1894–1971; Soviet leader 1953-1964)  so called "Secret Speech" (On the Cult of Personality and Its Consequences) to the 20th Congress of the Communist Party of the Soviet Union on 25 February 1956 in which he provided a detailed critique of the rule of comrade Stalin (1878-1953; Soviet leader 1924-1953), especially the bloody purges of the late 1930s.  Some had however already refused to deny what had become obvious to all but avid denialists, The God that Failed a collection of six essays published in 1949 by poet Stephen Spender (1909-1995) et al in which the writers lay bare their sense of betrayal and disillusionment with communism because of the totalitarian state built by Stalin which was in so many ways just another form of fascism. 

Idiot, Imbecile & Moron

Idiot, imbecile, and moron were in the early twentieth century used in a psychological classification system, each one assigned to a specific range of abilities.

Idiots: Those so defective that the mental development never exceeds that or a normal child of about two years.

Imbeciles: 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.

Morons: Those whose mental development is above that of an imbecile, but does not exceed that of a normal child of about twelve years.

Of these three words moron is the newest, created only in the early twentieth century, coined specifically for the purpose of medical diagnosis.  Moron is from the Ancient Greek mōros (foolish, stupid), the root shared with the rare morosoph (a learned fool).  Imbecile dates from the sixteenth century, an adjective meaning "weak, feeble", from the Classical Latin imbecillus (weak, weak-minded) and not until the early nineteenth century did it begin to be used as a noun.  Moran actually replaced “feeble-minded” and “simpleton” (introduced in 1846) but neither were ever standardised in the medical lexicon.  The clinical use is now obsolete but the generalized use of all three is well established as terms of opprobrium for someone who acts in some dopey way or says something stupid, but, the convention is now they can only be applied to someone not cognitively impaired, an inversion of their original purpose when part of the system of classification.

In the early 1900s, as the profession of psychiatry became more accepted within medicine, the system of classification became increasingly scientific: Idiots were those with IQs between 0–25, imbeciles between 26-50 and morons between 51–70.  The interest in the then fashionable field of eugenics saw further refinements with a teleological flavor: the concepts "moral insanity", "moral idiocy"," and "moral imbecility" used by the emerging field of eugenic criminology, which held crime could be reduced by preventing "feeble-minded" people from reproducing and the US Supreme Court used the terminology in the judgment of forced-sterilization case Buck v Bell (274 U.S. 200 (1927)). 

The later introduction of retard, retarded & retardation was a genuine attempt to de-stigmatize those once labeled idiots, imbeciles & morons.  The process was the same as the invented word moron replacing “simpleton” and “feeble-minded” (from the Latin flebilis (to be lamented).  Retarded was from the Latin retardare (to make slow, delay, keep back, or hinder) and was first used in relation to developmental delay in 1895 and was introduced as an alternative to idiot, moron, and imbecile because at the time it wasn’t derogatory, being a familiar technical term from engineering and mathematics but the associative connection meant that by the 1960s, it had become an insult.  As "retarded" and the related clinical terms from psychiatry appeared on the euphemism treadmill they gradually assumed their derogatory connotations.  It seems to be an organic process in language, an original term, neutral in meaning, enters public use and because of the thing with which it’s associated, becomes pejorative, the process noted also with words which become racial slurs.  It’s a very particular process: “Chinaman” thought pejorative while “Englishman” is not; “Aussie” a term of endearment whereas as “Paki” is a slur although that too is circumstantial, commercial television station Channel 9 (Australia) using “The Pakis” in their promotional material for the coverage of the 1983-1984 cricket season.  It wouldn’t now be used.

So, as sympathy emerged for various sensitivities, the search for connotatively neutral replacements settled on variations of “intellectual disability”, the new sub-categories being profound, severe, and moderate levels.  The World Health Organisation (WHO) in 1968 published (in an out-of-sequence amendment to the ICD-8 (International Statistical Classification of Diseases and Related Health Problems) a classification of intellectual disability (ID), based on what they called “relative degrees of cognitive functioning”:

Profound ID:          IQ below 20-25

Severe ID:             IQ 20-25 to 35-40

Moderate ID:         IQ 35-40 to 50-55

Mild ID:                 IQ 50-55 to 70

The alignment with the old system was idiot=profound, imbecile=moderate/severe and moron or feeble minded=mild but, by the time the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) and ICD-10 were published in 1994, the profession was moving away from the use of raw IQ scores to something more nuanced, the DSM noting the importance of assessing “dysfunction or impairment” in at least two areas including “communication, self-care, home living, social/interpersonal skills, use of community resources, self direction, functional academic skills, work, leisure & health and safety”.  The ICD noted “mental retardation is a condition of arrested or incomplete development of the mind, which is especially characterized by impairment of skills manifested during the developmental period, contributing to the overall level of intelligence- cognitive, language, motor and social abilities”.  However, the IQ baselines remained and the DSM-5 refined the model further, noting an intellectual disability should be defined by:

(1) Current intellectual deficits of two or more standard deviations below the population mean, which generally translates into performance in the lowest 3% of a person’s age and cultural group, or an IQ of 70 or below.

(2) Concurrent deficits in at least two domains of adaptive functioning of at least two or more standard deviations, which generally translates into performance in the lowest 3 % of a person’s age and cultural group, or standard scores of 70 or below.

Both assessments need to be measured with an individualized, standardized, culturally appropriate, psychometrically sound measure and needed to assess (1) conceptual skills (communication, language, time, money & academic), (2) social skills (interpersonal skills, social responsibility, recreation & friendships) and (3) practical skills (daily living skills, work & travel).  US legislation in 2010 required the terms "mental retardation" and" mentally retarded" be removed from federal records and replaced with "intellectual disability" and "individual with an intellectual disability", a change reflected in the DSM-5 (2013).