As a mother, I would not send my 15 year old to Caltech. There just isn't enough adult supervision and very bright kids can get up to unhealthy sorts of insanity. A lot depends on what Hovse a student sorts into, and some are more sane than others, but I wouldn't want my child there at 15.
I echo the sentiments about Caltech, although my experience is not so recent. I was in the dorms as a typically-aged college student, and I'd say "insufficient adult supervision" sums up my concerns well. Some of the young kids (14, 15, 16 yo) in my dorm did okay, but in hind sight as a parent, I'd say most of them would have been better off at home. The kids I know of who started at 17-18yo but were "over-prepared" as freshman fared much better in the long run than the very young, on average. I think the extra maturity went a long way in getting the most out of the experience.
Caltech may be a unique case, but I'd say my experience there has significantly influenced how I advocate for my kids - I am very eager to have them at home until 17-18yo. We have not grade-accelerated our public school kids, although test scores suggest they could have easily managed multiple skips. We are lucky to have some great teachers who have helped keep them challenged. They (twins) start middle school (6th grade) in Sept. at 11 yo, and it is still possible they'll run out of curriculum before they finish high school. But we're lucky to have a great (for now, anyway) state U. close by where they can take classes as high schoolers in that case.
