I'm confused by my 7.2 year old son who just took the WISC IV and WIAT III test. What's more confusing is the psychologists response such as "his scores are underestimate of his true ability, due to anxiety and fatigue." Following are his results. Please someone help me understand why there's such a discripency among his VCI and PRI.

VCI-102
PRI-134
WM-107
PS-132

I see the scatter, however when he took the WIAT III there was NO LD or ADD or ADHD or any other disability. Kind of weird to me.