In 1887 Langdon Down was the first to coin the term ‘idiot savant’Howlin and several co-authors, including Sir Michael Rutter, wrote in a 2009 paper:
Here are Pam Heaton and Gregory Wallace from a major 2004 review:
Down (1887) was the first to coin the term ‘idiot savant’
The term ‘idiot-savant’ was first used by Down (1887)From 1999, Pam Heaton again, as well as Linda Pring, Beate Hermelin, and others:
The term "Idiot-Savants" was first used by Langdon Down in 1887Darold Treffert, often described as the authority on savants, has written accounts along these lines:
However, the first specific description of savant syndrome took place in London in 1887 when Dr J. Langdon Down gave that year’s prestigious Lettsomian Lecture at the invitation of the Medical Society of London... In 1887, ‘idiot’ was an accepted classification for persons with an IQ below 25, and ‘savant’, or ‘knowledgeable person’, was derived from the French word savoir meaning ‘to know’. Down joined those words together and coined the term idiot savant by which the condition was generally known over the next century.That's from a 2009 paper. There seems to be an impressive consensus in the literature that Down coined the term "idiot savant" in 1887 (here is the source cited in all of the above), a claim that Treffert has made since the late 1980s, and many others have followed suit.
So far as I can tell, this consensus is wrong. Edouard Seguin, who died in 1880, is well known for having written about savants. He wrote about the famous pianist Blind Tom Wiggins, for instance, in a book published in 1866. And in a short 1870 paper, he is quoted as using the term "idiot savant." Here it is (spelling from original):
Among the wealthier classes, idiocy is not only oftener aggravated by accessory diseases, but also complicated with abnormal semi-capacities or disordered instincts, which produce heterogeneous types to an almost unlimited extent. It is from this class, almost exclusively, that we have musical, mathematical, architectural, and other varieties of the idiot savant; the useless protrusion of a single faculty, accompanied by a woful general impotence.Seguin's use of "idiot savant" did not pass unnoticed in the literature. For example, in the BMJ in 1875, George W. Grabham quotes and takes issue with Seguin's views (spelling from the original):
A curious class may be termed that of the idiot "savans", in whom one or more faculties are amazingly developed, perhaps to the detriment of the rest. One has a marvellous power of acquiring languages and musical knowledge; another, great mechanical skill and original constructive ability; a third, though very childish, is no mean mental arithmetician; a fourth remembers all he reads; a fifth delights in dates; while a sixth can tell the time when awakened from sleep. General improvement has taken place in all these cases.It's possible Seguin was not the first to use "idiot savant" but he does get this honor in the online OED, which quotes Seguin's 1870 paper but does not mention or quote Langdon Down.
Dr. Seguin, a well known authority on idiocy, has given the support of his pen to a theory "that idiocy is found in its simplest forms among the labouring classes, and that, among the wealthier classes, it is not only oftener aggravated by accessory diseases, but also complicated with abnormal semi-capacities or disordered instincts, which produce heterogeneous types to an almost unlimited extent. It is from this class almost exclusively that we have musical, mathematical, architectural, and other varieties of the idiot savant; useless protrusion of a single faculty, accompanied by a woeful general impotence". I am quite unable to agree with this view; my experience of many of these idiot "savans" proving them to have sprung from parents in humble circumstances, and leading me to believe them to have resulted in many instances from hereditary insanity.
In a footnote, Spitz (1995) provides a small trace of dissent, noting that Down himself made no claim, in 1887, to having coined "idiot savant" and indeed he seems to be using an existing term. Spitz did not try to find who did coin "idiot savant," but you can't blame Down for the false consensus.
And it hardly matters, to current-day autistics, who exactly coined an obsolete term in the 1800s. Langdon Down and Edouard Seguin probably don't care about their h-indexes. There are many vastly more important issues related to the term "idiot savant" and the human beings who were characterized this way, and the still-dominant view that strong autistic abilities are useless protrusions (recent example here).
But it does matter when telling an inaccurate story becomes the standard in the autism literature, over the course of 20 years or more. This is far from the only instance. And this is an especially easy story to verify (or not).
HOWLIN, P. (2012). Understanding savant skills in autism Developmental Medicine & Child Neurology DOI: 10.1111/j.1469-8749.2012.04244.x
Grabham, G. (1875). Remarks on the Orgin, Varieties, and Termination of Idiocy BMJ, 1 (733), 73-76 DOI: 10.1136/bmj.1.733.73-a
Seguin, E. (1870). Art. XXXIII.-New Facts and Remarks concerning Idiocy: being a Lecture delivered before the New York Medical Journal Association, October 15, 1869 American Journal of the Medical Sciences, 59 (129), 518-519