Read through this thread
http://giftedissues.davidsongifted....ing_with_kids_with_low_W.html#Post112284

and run the search term
Processing Speed
or
PS or PSI

most kids here don't struggle with both, but some do.

It's also possible that your son isn't struggling with both, but that his perfectionism is being reflected in the 'average' scores.

Do these descriptions of WM and PS sound like his bottlenecks?
http://en.wikipedia.org/wiki/Working_memory

http://en.wikipedia.org/wiki/Wechsler_Intelligence_Scale_for_Children

Maybe start by writing down a list of all the things that worry you about your son, and choosing a 'key' place to start, that if he made progress, lots of good things would happen...

Perhaps being able to talk about inferences when he reads so he can get into a higher reading group? Or 'Mental Math' tricks so he isn't so pokey in Math?

Has ADHD or ADD been suggested as a possible problem? Is he having http://en.wikipedia.org/wiki/Absence_seizures? Is he slow at getting ready for school? Does he need paper systems to keep multistep task from overwhelming him?

One way you can help right off is Flylady.net You'll be called on to keep the house extra-extra kid-friendly for a kid who doesn't 'self-organize' easily.

Love and More Love,
Grinity


Coaching available, at SchoolSuccessSolutions.com