I’m reading around in some rather disgusting American eugenics literature for historical purposes. I have found a letter from Mary Dendy to Karl Pearson, dated 1912, that reads partially as follows:
Imbeciles – It is difficult to find a definition of these which does not apply for low-grade Feeble-minded. They may be described as low-grade F.M. who are not able to be taught the proper care of their persons and whose habits require constant attention. They are apt to be excessively restless, to “echo” (i.e. repeat words instead of answering them.) They are occasionally destructive and apparently cruel, though it is probable that their acts of cruelty are due not to an instinct to give pain, but an instinct to destroy. If able-bodied they can be taught to work, i.e. to repeat the same movement over and over again, in a purely mechanical manner. They often use repeated movements of some part of the body quite without purpose, as striking the head rhythmically with the hand. Their articulation is generally very defective and they sometimes have little or no speech.
She describes “low-grades” as “sometimes having special mental gifts, but more commonly low-grade all round”.
Hmm. It always amazes me when I run into this stuff and remember that some people actually believe that autistic people didn’t exist until Leo Kanner. We were — some of us anyway — spread out among a number of classifications of “mental defectives”, which is what they considered a broad range of people back then.