The effects of benzedrine sulphate and caffeine citrate on the efficiency of college students

Abstract

An early experiment failed to show significant effects of benzedrine sulphate on group means on reading, multiplying, and analogies scores. Subjective reports from both drugged and non-drugged subjects indicated widely varying subjective effects and the influence of suggestion. 129 students were divided into 3 groups equated for intelligence and sex. At the beginning of a two-hour period one group was given 15 mg. of benzedrine sulphate, another group 5 grains of caffeine citrate, and a third a sugar capsule. All were tested during the 2 hours on three 10-second trials in tapping, a reading test, a vocabulary test, and an analogies test. Among the conclusions reached are the following: "The experimental evidence to date concerning the effect of benzedrine sulphate and caffeine citrate on human efficiency is conflicting." "When college students are unaware of the contents of the pills administered and when they are told that each pill should be stimulating, the non-drugged group seems to improve practically as much as the benzedrine and the caffeine groups." "Reported clearness of thinking and rapidity of work are not substantiated by the group results." (PsycInfo Database Record (c) 2025 APA, all rights reserved)