[D]eification of intelligence can have a truly perverse moral consequence that we often fail to recognize—the denigration of those low in mental abilities measured in intelligence tests. Such denigration goes back to the very beginnings of psychometrics as an enterprise. Sir Francis Galton would hardly concede that those low in IQ could feel pain: The discriminative facility of idiots is curiously low; they hardly distinguish between heat and cold, and their sense of pain is so obtuse that some of the more idiotic seem hardly to know what it is. In their dull lives, such pain as can be excited in them may literally be accepted with a welcome surprise.
Milder and subtler version so f this denigration continue down to the modern day. In 2004 author Michael D’Antonio published a book titled The State Boys Rebellion about the ill treatment of boys in the Walter E. Fernald School for the Feebleminded and how a group of boys residing at the school rebelled against this treatment. Disturbingly, however, reviews of the book tended to focus on the stories of those boys who later were found to have normal IQs. The The York Times Book Review (June 27, 2004) titled its review “A Ledger of Broken Arms: Misdiagnosis and Abuse at a School for the ‘Feebleminded’ in the 1950s.” We might ask what in the world does “misdiagnosis” have to do with the issue of highlighting the ill treatment in these institutions? The implication here is that somehow it was less tragic for those “properly diagnosed”—whatever that may mean in this context. Shades of Galton, and of the dark side of the deification of intelligence, are revealed in the reactions to this book.

Keith Stanovich, What Intelligence Tests Miss: The Psychology of Rational Thought, New Haven, 2009, p. 53