Forty-two male college students were divided into two groups. One group was given 10 mg. of benzedrine sulfate, and the other a placebo at the first session. They were then given a form of the Otis self-administering tests of mental ability (higher form). One week later, the groups were rotated and tested with an alternate form. Under the conditions of the experiment, we found that:1. The 10 mg. of benzedrine were without a favorable effect on the Otis test score.2. A small but statistically significant practice effect was noted upon retesting.Abstract Teaser