It's really hard to get any kind of reliable IQ score on an autistic child, especially one as young as your DS. Personally, I refused to allow IQ testing at that age, although the school did push for it. Traditional IQ tests are strongly based on verbal language skills and this is an area that most autistic individuals struggle with, especially as young children. As they get older and their language skills develop more, it may be possible to get a more accurate IQ result. Some studies have found that non-verbal IQ tests may be more appropriate for individuals with autism.
I did consent to IQ testing at his most recent triennial eval, when he was 8. But I insisted that our private psychologist do the testing and that she would use both traditional and non-verbal tests. For my DS, part of the difficulty is that traditional IQ tests are language based and non-verbal IQ tests are visually based. In addition to autism, DS has mild visual impairments. They don't make tests for people who are both language impaired and visually impaired. So we weren't expecting to get an accurate result from either test.
What we were hoping for, and what we did get, was some really useful information from the subtests. His full scale IQ (FSIQ) score on the traditional test was low, much lower than I had expected. But the psychologist explained that the FSIQ was useless, because there was so much scatter in his subtests (something like 30+ points). But the subtests gave us a lot of insight into where he struggles and where he shines. He did slightly better on the non-verbal test. But the psychologist told me that once the visual material got too detailed/complex, eye fatigue set in and DS couldn't make sense of what he was looking at.
The psychologist wrote a very thorough report on the testing for the school and explained all the issues.
The school psychologist did achievement testing with DS. Achievement testing is more like regular academic testing. Psychologists like to compare IQ tests to achievement tests. The theory is that IQ tests measure ability and achievement tests measure performance. Ideally, the scores of both sets of tests should be similar, meaning the student's performance matches his/her ability. If the IQ score is considerably higher, then the student is not performing to his/her ability, which could be a motivation issues or a sign of a learning disability. Theoretically, the achievement tests score can't be higher than the IQ test scores, because an individual can't perform above his/her ability. DS (of course) did have that mix of IQ score at the low end of the bell curve and achievement tests at the high end of the curve. The school psychologist was amazed and kept telling me his test results were "theoretically impossible". I told her that DS hadn't read her theories. She added a "savant" label to DS's profile, since that's the only way she knows to explain his scores.
Of course, the theory only has value if you believe the IQ scores to be a true and accurate measure of the person's ability. Generally, for people with autism they are not. That's the limitation of the test, not of the individual being tested.
DS is due for another triennial next year. We will do IQ testing again, although I haven't decided if I will let the school psychologist do it or have our private psych do it again. I honestly don't care about the full scale number. I'm interested to see if his sub scores change, to see where he's improved and where we still need to focus on building his skills.
My my advice to you is to not be afraid of an IQ score. I strongly suggest waiting a few years for testing to let your DS's skills develop. If and when you do go forward with testing, don't be afraid of a low score. A low IQ score doesn't not necessarily mean low intelligence. It might mean his intelligence cannot be accurately measured by the test. Don't get hung up on the full scale score AND don't let anyone else - family, teachers, doctors, therapist - get hung up on it either. Subtest scores can be a lot more valuable than the FSIQ, so focus on the information you get from those.
Last edited by Gena; 04-09-2014 at 11:25 PM.
Reason: I'm terrible at spelling.
Gena
DS, age 11 and always amazing
“Autistics are the ultimate square pegs, and the problem with pounding a square peg into a round hole is not that the hammering is hard work. It's that you're destroying the peg." - Paul Collins, Not Even Wrong