Professors Ernest Sternglass (University of Pittsburgh) and Steven Bell (Berry College) have assembled cogent, conclusive evidence indicating that nuclear radiation is associated with impaired cognition. They suggest that Scholastic Aptitude Scores (SATs), which have declined steadily for 19 years, will begin to rise. Their prediction is based on the presumption that radioactive fallout from an extremely large number of nuclear bomb tests of the 1950s/1960s was deeply involved in the dramatic decline of SAT scores during the 1970s. Additional facts supporting the Sternglass/Bell hypothesis include: (1) the steady decline in SAT scores beginning 18 years after 1945, the year in which the first series of atomic bombs were detonated; (2) beginning with 1977/78, a corresponding abrupt slowing in the decline of SAT scores; (3) strong parallel of SAT scores and nuclear tests evident in SAT verbal score averages; (4) sharpest decline in SAT scores documented for youths born in precise years when annual kilotons detonated in Nevada was greatest; and (5) geographic differences. This and other information strongly support the conclusion that fallout from nuclear weapons was a significant and previously neglected factor in the recent decline of cognitive ability among young Americans. (JN)