Gifted Today but Not Tomorrow? Longitudinal Changes in Ability and Achievement during Elementary School

Abstract

The term gifted implies a permanent superiority. However, the majority of children who score in the top few percentiles on ability and achievement tests in 1 grade do not retain their status for more than a year or 2. The tendency of those with high scores on one occasion to obtain somewhat lower scores on a later occasion is one example of regression to the mean. We first summarize some of the basic facts about regression to the mean. We then discuss major causes of regression: errors of measurement, individual differences in growth, changes in the content of the developmental score scale, and changes in the norming population across age or grade cohorts. We then show that year-to-year regression is substantial, even for highly reliable test scores. Different ways of combining achievement and ability test scores to reduce regression effects are illustrated. Implications for selection policies and research on giftedness are also discussed.