Did they give you the scores for the tests within the subtests? I'd want to know what the unusual scatter they mentioned actually looked like and it might give you more insight into whether the VCI and PRI really look like low-ball estimates b/c they were dragged down by some of the tests being much lower than others.
That said, like others, I disagree that the scores you have are indicative of a child who wouldn't be performing as highly as is he. There have been a number of articles posted here over the years that point to the importance of working memory in school achievement. Just a quick google search brought up this summary of a study that found that working memory is more important that overall IQ in school achievement:
http://sharpbrains.com/blog/2010/01...r-predictor-of-academic-success-than-iq/Just as an anecdote, I have one child with DYS level GIA (a combo of VCI and PRI) and VCI that is just shy of DYS levels. B/c her working memory is pretty average and she has ADD, she is a high performer in grade in a high performing school, but she doesn't stand out among other kids in the GT programming as dramatically different the way I might expect someone with her IQ level to.
I've also, over the years, known a couple kids with profiles along the lines of your ds' but with overall lower FSIQ who are very high achieving. These kids had truly average VCI and PRI scores (pretty much the entirety of the indices were right around the 50th percentile), but they had high PSI and/or WMI and they perform dramatically better than I would generally expect given the overall IQ and VCI/PRI scores. While none of them are grade accelerated, they are kids whose achievement scores are pretty consistently advanced on state tests and whose nationally normed tests come in at the mid to upper 90s (percentile) across the board and who are in GT classes. One of these kiddos, whose mom has shared a lot, has had IQ tested more than once with experienced testers and has consistently had pretty average/high average overall scores with the VCI and PRI consistently average.
I say all of that not to say that your ds' scores are absolutely correct or the be all end all of his ability, but b/c it is entirely possible for WMI and PSI to play an important role in school success. Neither is useless or unimportant, they are just a better indicator of skills that support one in success than they are depth. For instance, kids with high VCI/PRI tend, in my experience, to come across as deeper, more abstract, able to make connections that are not readily obvious, etc. Kids with high WMI/PSI tend to be good students who can master the material and perform very highly but perhaps without creating new knowledge so much as mastering the given knowledge. Both pieces would be the ideal situation, but most of us don't get ideal!
