To test the hypothesized cumulative advantages of educative factors, the science-achievement scores on a 69-item test of science knowledge of 1,284 young adults, ages 26 to 35, surveyed by the National Assessment of Educational Progress (NAEP) in 1977, were regressed on three composite independent variables: motivation and prior and current educative experiences. The test scores were related significantly to prior experience-embodied variables, such as parental socioeconomic status, respondent education, and specific scientific training, as well as to motivation to learn and current amount and intensity of information acquisition, such as news media exposure and reading. Early educative experience predicts current educative activities and motivation; and all three factors contribute significantly and independently to the prediction of achievement.