Not trying to be flippant, but from observation of what works for me and for lots of friends, I strongly suspect that treating them as though they are really really smart is a strategy that works well for kids in general, not just the ones who are really really smart!
I agree that parenting by close observation and starting from the assumption that what the child is trying to communicate is meaningful would be useful to any child, not so much by raising the IQ - although that may happen to a certain degree, but by communicating that 'life is good'- it's save to use every bit of your genetic heritage that points to giftedness here in the world.
I also don't want to give the message that this is the best way to parent, or that people who don't parent that way are harming their child in any way - I'm a firm believer that the way
you is the best way for your child. Parenting this way has drawbacks too, actually,and since we're all perfectionist around here, DS13 might be able to tell you about them in great detail!
(Essentially, establishing independence in adolescence from parents who are so 'interested' in one can be 'a pain in the')
Best Wishes to all,
Grinity