Intellectual giftedness is an intellectual ability significantly higher than average. It is a characteristic of children, variously defined, that motivates differences in school programming. It is thought to persist as a trait into adult life, with various consequences studied in longitudinal studies of giftedness over the last century. There is no generally agreed definition of giftedness for either children or adults, but most school placement decisions and most longitudinal studies over the course of individual lives have been based on IQ in the top 2 percent of the population, that is above IQ 130.The various definitions of intellectual giftedness include either general high ability or specific abilities. For example, by some definitions an intellectually gifted person may have a striking talent for mathematics without equally strong language skills. In particular, the relationship between artistic ability or musical ability and the high academic ability usually associated with high IQ scores is still being explored, with some authors referring to all of those forms of high ability as "giftedness," while other authors distinguish "giftedness" from "talent." There is still much controversy and much research on the topic of how adult performance unfolds from trait differences in childhood, and what educational and other supports best help the development of adult giftedness.