Dr. J. Langdon Down and 'Developmental' Disorders

Darold Treffert MD

Autism is not a new disorder, the ‘explosion’ in autism cases, whether apparent or real, notwithstanding.

While it is true the first description of “early infantile autism” by Dr. Leo Kanner did not occur until 1943, certainly disorder did not begin there. Surely autistic disorder, like mental retardation, has been one of man’s medical maladies from earliest times. In fact until 1943 autistic disorder was generally simply subsumed under the category of ‘mental retardation.’ Sometimes that is still the case of mistaken diagnosis even today. In fact, the present-day practice of reclassifying cases from mental retardation to autistic disorder may account for some of the ‘explosion’ in new cases of autism.

As I studied Dr. J. Langdon Down’s (1887) first description of the ‘idiot savant’ (an unfortunate term but more about that later) I was curious as to what he might have observed, or written, about those persons with autistic disorder who certainly were among the many hundreds of patients with mental retardation that he had seen during his long career, and who most certainly were represented in his examples of savant syndrome. What I found in those early descriptions was surprisingly astute, and, very avant-garde, with respect to what we now call autistic disorder. Let me explain.

In an 1887 book entitled On Some of the Mental Affections of Childhood and Youth, J. Langdon Down, MD published “The Lettsomian Lectures delivered before the Medical Society of London in 1887 together with other papers.” It was there he found “a convenient place to describe an interesting class of cases for which the term ‘idiots savants’ has been given, and of which a considerable number have come under my observation. This name has been applied to children who, while feeble-minded, exhibit special faculties which are capable of being cultivated to a very great extent.” He then describes a number of cases of children with the artistic, musical and numerical skills that have so regularly been described in by other observers, including myself, this past 117 years (Treffert, 2000). He also keenly pointed out that “extraordinary memory” was linked with the special abilities in the savant, a finding reported consistently in all of the cases documented in the literature in the many years since that first description. One of his patients, for example, had memorized large portions of the Rise and Fall of the Roman Empire and could repeat them back verbatim.

Dr. Down’s further description of savant syndrome is fascinating, but I want to concentrate here on his observations about autistic disorder itself. How many of Dr. Down’s patients would we now classify as having autistic disorder, as opposed to mental retardation? And what were Dr. Down’s thoughts about the etiology and classification of this group of patients who differed in a number of ways, by his own descriptions, from more traditional and familiar forms of mental retardation that he otherwise so accurately described in his writings and lectures?

Late-Onset (Autism with Regression) and Early-Onset Autistic Disorder

Down divided mental retardation into several categories by causation. In his terminology, one form, “Congenital,” encompassed those cases with hereditary causation due to “germ cell” or “sperm cell” variations. These cases by far made up the “majority” of individuals he had seen in his 30 years at Earlswood, he stated, and fully 10% of that number had what is now called Down’s Syndrome. He termed a second form of mental retardation “Accidental.” He characterized these cases as instances in which injury or disease late in the pregnancy, at birth, or after birth, appeared to be causal.

However a third category of patients began to intrigue Down, a group of persons “impossible to include” in either the congenital or accidental causes. In this third group of individuals there was a) no history of accident nor of any illness akin to accident; b) there was “no reason to regard them as congenital — all of the historical evidence, as well as all the physical evidence, positively refuted any such idea”; c) these children carried none of the usual “physical aspects” of mental retardation; and d) some such children seemed quite normal intelligence-wise from birth, but then at about age 6 or so suddenly “lost wonted brightness” “lost speech” and had “suspension of mental growth.” “Under what head, therefore, were they to be placed?” Dr. Down asked. Eventually Dr. Down applied the term “Developmental” to this third group. It is in this group of individuals that so many features of what now is called Autistic Disorder appear. It is interesting, and noteworthy, that Down termed these cases “developmental’ because fully a century later autistic disorder is now classified in present day terminology as a “developmental disorder.”

Dr. Down described in some detail the unusual features of these cases that simply did not fit the typical clinical picture of mental retardation that he had been accustomed to seeing. In these children the early months of childhood were uneventful and “intelligence dawned in the accustomed way.” But later, around age six or so, ” a change took place in that the child’s look had lost its wonted brightness; it took less notice of those around it; many of its movements became rhythmical and automatic.” There was “cessation of increasing intelligence”, deferred speech and “lessened responsiveness to all the endearments of its friends.” Dr. Down writes “I have had many examples of children who had spoken well and with understanding, but who lost speech at the period of the second dentition, and had also suspension of mental growth.” Dr. Down provides several examples. One was a boy who “attracted no particular attention during the first six years of life” but then “during the period of second dentition” suddenly lost speech. “He heard everything that was said, but never replied to a question.” This child did gradually regain some speech but “afterwards always spoke of himself in the third person.” The other case example was that of two brothers who also “both lost speech at the period of second dentition.”

Are these cases of what now would be called late-onset (autism with regression) autistic disorder? It appears so to me.

But there was yet another group of individuals that seemed to Dr. Down to differ from the more typical mental retardation cases he was accustomed to seeing. These persons, like those in the “developmental” group showed none of the usual “physical aspects” of mental retardation. These were children who were “bright in their expression, often active in their movements, agile to a degree, fearless as to danger, persevering in mischief, petulant to have their own way. Their language is one of gesture only; living in a world of their own they are regardless of the ordinary circumstance around them, and yield only to the counter-fascination of music.”

These children, unlike the late-onset group, did not reach developmental milestones normally, gain speech, and then regress. Rather Down describes the parental expectations for these children thus: “I know nothing more painful than the long motherly expectancy of speech; how month after month the hopes are kept at high tension, waiting for the prattle which never comes. How the self-contained and self-absorbed little one cares not to be entertained other than in his own dream-land, and by automatic movements of his fingers or rhythmical movements of his body… they have well-formed heads, finely-textured skins, well-chiseled mouths, sparkling eyes, features when in repose leading one to augur only brightness and intelligence… he runs to you when called but makes no response in words. He returns your kiss with a bite, and runs away with agile steps, rolling his head with a horizontal swaying motion…”

“Early-onset autistic disorder”? It appears so to me.

The Dawn of “Developmental” Disorders”

How to classify and explain such atypical cases, Dr. Down inquires in his writings.

His conclusion, at least with respect to what appear to be what would now be termed “late-onset autistic disorder” cases: “They form a class of cases which I have suggested should be called the “Developmental,” as contradistinguished from the “congenital” on the one hand, and the “Accidental” on the other.” In his writings it is unclear whether Down would include what appear to be what would now be termed the “early-onset autistic disorder” in his “Accidental” or “Developmental” categories. In some places his descriptions equate such ‘from birth’ cases with ‘accidents’ late in pregnancy or very early after birth and at other times he seems to include this group of persons into the developmental category where, in his view, there was some problem early in pregnancy which resulted in the “developmental” injury and subsequent disability.

Regardless of whether “accidental” or “developmental” this early-onset group had special features relating to head shape that caught Dr. Down’s attention. Each of these children, he noted, had a “characteristic crania — they are dolicheocephalic and and are prow-shaped anteriorly.” Regarding the origin of this finding he states “there is reason to believe that in these cases there has been an arrest of the synostosis of the medio-frontal suture which should have taken place during intra-uterine life” specifically “during the later months of pregnancy.” He concluded that this deferred synostosis and consequent deformity was of no particular consequence in and of itself, but he speculated “the same cause which arrested the bony union has also arrested the development of the cerebral centres and rendered them more unstable”, producing central nervous system “growth” but not “development.”

Those observations are particularly interesting in terms of present-day research regarding head size and autism (Wallace & Treffert, 2004) (also see the posting on this website titled Head Size, Autism and Savant Syndrome). In brief, head size at birth in autistic children tends to be smaller than most infants. There follows then a rapid and excessive growth in head size and increase in brain volume beginning several months after birth and continuing to age 2 to 5. This excessive brain growth slows by middle to late childhood to where by adolescence and adulthood head and brain size of autistic persons does not differ significantly from the healthy average. The earlier the onset, the faster the rate, and the longer the period of excessive brain growth, the more severe the Autistic Spectrum Disorder. It is speculated that there is disrupted “development” (organization) of the brain itself during this period of excessive growth.

Down’s observations were not focused on head size, but rather on head shape. But the fact he noted some unusual findings related to the head configuration in this group of puzzling patients is interesting in light of the recent autism and head size observations.

Today’s findings regarding head size and autism do not focus on head shape, or the specific”sutures” or “synostoses” that Down singled out. But his speculation that the same causes and delays that affected bony development of the head might correspond with, or be a marker of, “arrested development” of the “cerebral centres,” rendering them unstable, and producing central nervous system “growth” but not “development,” was a rather astute observation and theory in view of present day findings and speculation regarding head size and autism.

It needs to be noted that while Dr. Down did single out head shape findings as notable and worthy of mention, he ascribed an entirely different significance to those findings than any present-day explanation. He felt these head shape findings were a marker of “arrested development” that expressed itself in terms of making these children “more unstable” and being more likely “to break down at one or other of the developmental epochs” such as “over-excitement in babyhood and by ‘over-pressure’ in schools at second dentition or puberty.” This of course differs markedly from present day theories regarding significance of head size and autism, and the causation of autism itself.

A Word About Prognosis

Dr. Down made some specific comment regarding the prognosis for what might now be termed, in my view, early-onset (from birth) autism cases compared to more typical mental retardation cases. He pointed out that in those persons where mental retardation was evident from physical features and other usual accompanying signs and symptoms, expectations regarding the future of these persons, with respect to education and development overall was often commensurate with the observed disability. But Down remarked that the mothers of these cases with “the sparkling eyes” whose features “augur only brightness and intelligence,” and whose behaviors were “self-contained and self-absorbed” (autistic in today’s terminology), often entertained the “strongest hope” for these children because, since they didn’t have many of the hallmarks of more typical mental retardation, they might show better “responsiveness to training and speedy gain of speech.” But, Down cautions, “I cannot enforce too strongly grave caution in the prognosis which should be given in such cases; they are the most disappointing which one is called on to treat,” basing his forecasts on observations of 30 years which “enabled me to study not only the present, but the future of such children” as well.

The Regrettable Term “Idiot Savant”

Dr. Down is often criticized for using the term “idiot savant” to describe what is now known more kindly as savant syndrome. At the time of Down’s writings, though, the term “idiot” was an accepted scientific term for “graver forms” of mental retardation (IQ of less than 25). Milder or less grave cases were classified as “imbeciles” (hardly a very kind term either). Down himself did not like those terms or that classification. He noted “this nomenclature is open to grave objection” for several reasons not the least of which was that “the gradations of mental incapacity are as numerous and delicate as are those of mental capacity among those who are doing the world’s work.” He goes on to write: “I have no great liking for the term idiot. It is so frequently a name of reproach.” He continued: “No one likes the name, and no mother will admit that her child deserves the title.” He viewed the term as “a great impediment” to the “early appreciation of the lesion and to its early treatment. Nevertheless he was stuck, as it were, with a term of scientific import in the idiom of his time, which, in 1887, did not carry the lack of dignity and the pejorative connotation the term now holds. Actually the term “idiot savant,” while descriptive of the disconnect between ability and disability, was an unfortunate choice not only because of the pejorative connotation later attached to it, but it was a misnomer as well because the vast majority of persons with savant syndrome have IQ’s measured above 25, some indeed as high as 114.

Leaving the regrettable choice of terms aside, Down’s description of savant syndrome is a masterpiece of astute observation, colorful description and concise summarization. He begins “This is a convenient place to treat of an interesting class of cases…” The paragraphs that follow touch on the musical, artistic and mathematical skills that have been reported in cases ever since and seen today, and link the phenomenal memory with these special skills so characteristically seen as well. It is worthy of re-visiting. Pages 58-61 of his book, re-issued in 1990, provide that colorful description.


Autistic Disorder, while not named such until 1943, has existed for the same long time as other forms of developmental disorder and mental retardation. It is not a new disorder. In his writings in 1887 Dr. J. Langdon Down did not separate out autistic Disorder from mental retardation, but there was group of patients sufficiently different from his ‘congenital’ and ‘accidental’ forms of mental retardation that he felt compelled to set us a new category-‘developmental’ — to describe a group of patients “impossible to include” in his two other categories of mental retardation. As he describes some of the traits and behaviors of some of these persons — “world of their own,” talking in the “third person,” being in a “dreamland,””echolalia,””self-contained and self-absorbed,” “automatic and rhythmical movements,” a countenance and “repose of brightness and intelligence,” lack of “physical features” of retardation, “no response in words,” and indeed elements of savant syndrome itself in this special group of persons — those point in the direction of what is now called autistic disorder as being the appropriate classification for some of these individuals whom Dr. Down had classified as mentally retarded.

Within this group of “developmental” cases, is a sub-group of children Down describes as lacking the more typical physical characteristics of mental retardation, who reached developmental milestones, including attaining speech, appropriately but then regressed. These children, because of this period of normal development followed by steep regression, coupled with the traits and behaviors described by Down, would probably be classified, in present day terminology, as late-onset (autism with regression) autistic disorder. The fact that such late-onset autism, with regression also is not a new phenomenon needs to be considered when assessing the present-day controversies surrounding the causes of such regression. Some of those proposed causes did not exist in Dr. Down’s day, yet the regressive from of autistic disorder was already present.

The fact that some of the persons Down described demonstrated what is now called savant syndrome, which he described in such colorful and accurate detail, also argues that some of Down’s patients had autistic disorder as opposed to mental retardation since savant syndrome is most commonly associated with autistic disorder. Rather than mental retardation.

Dr. Down was a very astute observer, limited to the technology, or lack of technology, and the terminology of his time. His observations, as it turns out, were very astute, and very avant-garde considering many present day findings including those having to do with early-onset and late-onset autism, and head size and autistic disorder. Down’s classification of these patients, which so intrigued and puzzled him, as “Developmental” in origin, was also an astute observation and insightful conclusion a whole century before its time.


  • Kanner, L. (1943) Autistic disturbances of affective contact. Nervous Child. 217-50
  • Down, J.L.(1887) Mental Affections of Childhood and Youth. London:Churchill (1990) reissued as Classics in Developmental Medicine, No. 5. London: MacKeith Press
  • Treffert, DA. (2000) Extraordinary People:Understanding Savant Syndrome. Lincoln, Nebraska:iUniverse.com
  • Wallace, G.L. & Treffert, D.A. (2004) Head size and autism. Lancet 363:1003-04

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