I haven't read through this entire thread. But, to respond to the OP's original questions: I live in a community with RIDICULOUS hothousing parents. Some of them are immigrants who come from a country where, to do well (go to a good university), you have to do exceptionally well on whatever test is administered. But, apparently, in that particular culture, there are BIG tests along the child's educational journey, so you are always preparing to do very well on some test. This particular nationality has brought the same sentiments here and so from age 18 months or so, they are hothousing their babies like crazy.

Then we have just regular ol' American pushy parents who hothouse for whatever their reasons are. What I have seen is this: my DS7 PG DYS son was NOT identified for our gifted program in K (really a nothing program of 45 min pull out fun-sey stuff once a week). Why? Well, in large part, to the untrained eyes of the teachers, my DS didn't look so special next to the hothoused children. The hothoused kids could read very well upon entering K (maybe at the 1st grade level). They could do very well, at whatever is taught at Kumon or the local weekend hothouse program. My DS upon entering K at 5 years old, was a very weak reader....not really interested. He strongly preferred watching the hour long Nova special on string theory and then taking the time to discuss the theory with DH. He was busy rewiring outlets in our house because he understood the principles of electricity and had the dexterity to do it (but would start to cry if he had to write out the alphabet).

Now my DS is in 2nd grade. The hothoused kids have started to "even out".