Well, first of all, social or emotional maladjustment is not a prerequisite for giftedness. It bothers me a bit to constantly encounter the "correlation" between high IQ and unhappiness. Secondly, IQ tests are not that accurate/precise at the tails so it makes more sense to look at the confidence intervals rather than a single number, in which case the bright/moderately gifted labels would overlap. The terms "bright" and "gifted" are used differently by different people at different times as well. Personally, I actually use the term "bright" far more often than "gifted" in reference to my own children, including the DS who cleared the DYS minimums by a large margin.