Many of the DYS families I have met all their children are PG. At the Davidson summit I feel like I see many siblings that are all part of the program. And of those families I have spoken with, they do say their kids scores within 5-10 points from each other. Maybe at the summit it is a self selecting group, as it is easier to bring the whole group of PG kids rather than just bring one and leave other kids at home?
In either case, we plan on having the Wisc-V administered for my son. Then we can really see if the results change due to difference in Wisc editions. When he took the Wisc-iv his ADHD was still affecting him greatly. Now, it seems medication changes and doses are at an ideal therapeutic level finally.