Now that I have read back through the middle of this thread, I have to comment on the regional piece. Whether it's regional, rural, or suburban, or something else, I don't know, but I do think it plays a large part. My experience living in a dense urban neighborhood in a city with one of the highest percent of college degrees in the nation, is that DH and I can talk about our son's abilities, gently, with other parents and they are all perfectly fine about it. A lot of parents know he's in math in a higher grade, and it's no big deal. There are other kids in the school who move around to different grades, and I've run into quite a number of parents over the past several years with kids at gifted schools, in gifted programs, or in the case of our school which has neither, parents who are open about their kids moving around to different grades when needed. We live in an area that's highly educated, but just as or more importantly, it's full of people who moved here from somewhere else and are very adaptable and open to change and difference. My southern hometown is culturally not as open to change and difference.
I expect it's more closely related to the general educational level of a given social circle than an issue strictly of geography. The general tendency to mentally remove 20 IQ points every time they hear a Southern accent aside, I would expect to run into less shock at the world "googolplex" in, say, Chapel Hill NC than in areas of Detroit or Boston with a population which has, overall, considerably less formal education.
Even in the metro area in which I live (Southern, but with a lot of transplanted Yankees), I can guarantee that certain discussions will go over far more easily in certain groups than in others. The parenting group geared toward professional women who expect to reenter the workforce? No problem most of the time. The parenting group whose membership is based solely on age and quantity of children? Eh...not so much. Although come to think of it, when I bring up my youngest (who was at one pointn nicknamed "Wednesday Addams" by her older sister), I get weird looks from pretty much everybody. Sometimes even including her dad.
