This chapter focuses on the largest source of common variance in achievement: general cognitive ability (g). Because an individual's general cognitive level is important to account for in any education and career decision, it should be included in any college- and career-readiness discussion and accounted for by any intervention designed to improve college and career readiness. To date, the predictive validity of traditional cognitive test scores on educational and occupational outcomes is quite similar across gender, ethnic-racial, and socioeconomic groups. A century of research has shown that general cognitive ability is highly predictive of both training outcomes and job performance. The chapter reviews the evidence of the prediction of long-term educational and occupational outcomes for both the full range and the right tail of the distribution. The strongest evidence for the long-term predictive validity of college admissions test scores on educational performance comes from studies of gifted and talented youth who have participated in a 7th-grade talent search.