Low Functioning

Since one of the major missions of my blog is discussion of autism, I introduce my brother in each post by saying that Michael is autistic, nonverbal and low functioning. I used to say retarded, but refrain from using that word now due to the negative connotations.

What does low functioning really mean?

Part of my brother’s diagnosis is that he is ‘profoundly retarded’. The diagnostic criteria for Mental Retardation in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV (TR)), published by the American Psychiatric Association, profound retardation is an IQ level below 20 or 25. The diagnostic categories of retardation in DSM-IV (TR) include:

  • Mild – IQ 50-55 to 70
  • Moderate – IQ 35-40 to 50-55
  • Severe – IQ 20-25 to 35-40
  • Profound – IQ below 20-25
  • Severity Unspecified – when IQ is not testable.

According to Robert Sternberg, in the Handbook of Intelligence, the American Association of Mental Retardation (AAMR) in 1921, emphasized using Binet’s [1] IQ test as criteria for three levels of mental retardation [2]:

  • Moron – IQ of 51–70
  • Imbecile – IQ of 26–50
  • Idiot – IQ of 0–25

DSM-5 renames Mental Retardation, Intellectual Disability, which is a much more humane way to designate those affected.

IQ testing

Testing of the Intelligence Quotient has been a delicate issue for many years. An interesting Wikipedia article cites Stephen Jay Gould, noted paleontologist, as criticizing the very concept of IQ testing. [3] Gould called the abstraction of intelligence to a single quantity, scientific racism[4] “Psychologist Peter Schönemann was also a persistent critic of IQ, calling it “the IQ myth”” [5] On the other hand, psychologist Arthur Jensen posits that even if a variety of cognitive tests were administered, their results would be highly correlated and that “there would still be a black-white gap on cognitive tests.” [6]

Testing Michael… seriously?

I don’t intend to debate the merits of IQ testing here (or probably in the foreseeable future). But I would like to meet the people who were able to test my brother, and how they came up with that number. Perhaps they can give me some hints as to how to get his attention, a task I have been wholly unsuccessful accomplishing.

History of treatment of mentally disabled

This is a huge subject. At the moment, I am slogging through the book Inventing the Feeble Mind, A History of Mental Retardation in the United States by James W. Trent, Jr. (University of California Press (1995)). In my view, the early history, which includes equating severe intellectual disability with criminality and lack of will, is a shameful one. More recent history is not that much better. I hope that I can find a way to synopsize the development of more humane treatment of the mentally disabled for this blog. It is important to remember where we’ve been, so we don’t repeat the same awful treatment that was meted out in the past.

“History does not repeat itself, but it does rhyme.” Attributed to Mark Twain.[7]

4 thoughts on “Low Functioning

  1. Jack – I haven’t had the opportunity to review the new DSM-5 as of this date. I’m pleased to read the powers that be have changed the diagnostic label of ‘Mental Retardation’ to ‘Intellectual Disability.’ Somehow the term doesn’t seem to have the same sting of stigma that comes with ‘mental retardation.’ Unfortunately it’s not any easier for the individual or those that love him/her. Thanks for the informative blog.

    • Hi Sheri,
      Thanks. DSM-5 is a very expensive book, published by APA. Just snippets are available. If it wasn’t so expensive and flawed, I would consider getting a copy.

      By the way, I scanned your blog tonight. Good grief, how awful for you and your husband. Will read in more detail, and am looking forward to the next installment.

      Best regards,


  2. I do think it is extremely hard to measure IQ, especially of someone on the autism spectrum. The tests are very language-based. As people with ASD often have language impairments they are at a natural disadvantage during testing; hence it’s very common for their IQ to be underestimated.

    My son was assessed as moderately-severely developmentally delayed at age 3, borderline/mild intellectual disability age 5 and average non-verbal IQ at age 11 but accompanied by a quite significant verbal intellectual disability. He can talk – actually he talks all the time – but his verbal reasoning is impaired. That said, by focusing on his verbal reasoning through speech therapy it’s improving.

    Presumably IQ is meant to be fixed and immutable, but my son’s experience suggests otherwise. He didn’t suddenly become smarter, but through therapy (and medication for his ADHD) we’ve been able to reveal something closer to his real level of intelligence.

    • Hi Benison, thank you for your comment.

      I agree that IQ is difficult to measure. At the very least, attention to the test is required. In the case of my brother, the diagnosis of profound retardation is not warranted, as he is, essentially untestable.

      I can’t see how IQ is immutable. I don’t know the literature, but just from a biological point of view, there are times of day, when I could do better on an IQ test than other times. If I take an amphetamine, I could do better as well. Does this mean that I’m smarter at those times, and smarter with speed in my system? One might be amenable to different modes of learning and thinking, which, if tested properly could indicate a different kind of intelligence.

      Thank you again for your comment.



Leave a Reply

%d bloggers like this: