Dextroamphetamine and measures of intelligence

A sample of 320 male high school students was drawn on the basis of their neuroticism and extraversion scores from a population of 2500 students. By following a 4 × 4 randomized block design (replicated 20 times) an attempt was made to study the effects of dextroamphetamine on the test scores of fluid and crystallized intelligence of high school children. The study lends support to the hypothesis that the drug will have a differetial effect on the test scores of fluid and crystallized intelligence.