ASD, Level 1 Children reported as having higher IQ

Check this out:

That picture was drawn by a four-year old. Remember the undiagnosed child from two posts ago? This is his creation. Im holding the mat I assigned him to sit on during Circle time to help with letter awareness and also to help with his understanding of my expectations. All the students have a letter to sit on and that letter will be 'theirs' for at least the next month.
This afternoon during Journal Time he came up to me and asked for his journal... really he looked at me and motioned his hands like "Where's mine? Give me mine." I recall this morning him throwing a 'fall-down on the floor, crying and hollering' fit with the substitute assistant because she took his Sign-In Journal before he had a chance to finish. So this afternoon I made sure he had his journal and color pencils and plenty of time to work.
He drew the majority of this picture from memory. I sat at the table with him as he worked so I saw the process. I saw him with his head down drawing the outline, then coloring it in, then mixing colors. Then I noticed him getting up and walking to where the mats are stored. He sifted through until he found his... I assume he was checking the colors because when he returned to the table he colored over the black roof with a dark purple color. When I realized he had reproduced the picture from the mat, I remembered something I heard at a training I attended about Autism... Children with ASD typically test higher on IQ tests than undiagnosed children.
This little boy is an example of that statement. He is the only child in the classroom that can write his full name and he is the only child that will sit at the table and concentrate long enough to produce such a picture... not to mention the hand-eye coordination he's mastered.
...Does he still run to blocks when he's bored? Yep. And he gets bored easily... But I can give him 12-16 piece puzzles to fix and he will sit and do them with no interruption. I must admit it makes me question the relevancy of sitting on the carpet for 15-20m if a child of higher IQ finds it a waste of his time?
..... Oh yeah... Discipline.... The whole "Children have to learn how to sit still and listen to the teacher  in grade and secondary school, so we are preparing them now." ......Hmmmmm... As I type this my brain is multi-tasking on how to reduce my Carpet Time and allow children more independent learning time.....