THE EFFECTS OF CONTINGENT AND NONCONTINGENT REWARDS ON THE I.Q. SCORES OF CHILDREN OF ABOVE‐AVERAGE INTELLIGENCE1

Abstract
This study investigated the effects of candy reinforcement on I.Q. test scores in first and second graders of above-average intelligence. Thirty-six subjects were randomly assigned to one of three groups and either given candy contingent on correct responses, noncontingently, or not given candy. After measuring all subjects on Form L of the revised Stanford Binet, each subject in the contingent group was given an M & M immediately following each correct answer on Form M, while a yoked-comparison subject received the same number of M & M's before responding to a question and therefore without regard to correctness of answers. It was expected that both types of candy administration would produce higher I.Q. change scores than the no-candy control group, but there were no statistically significant differences among the three treatments. The differences between the first and second test scores were 4.17 (contingent), 4.67 (noncontingent), and 1.00 (no reinforcement). Reasons for this failure to replicate previous findings were discussed.