The present experiment demonstrated a procedure analyzing the behavior of controllers by measuring undergraduates’ responses that produced consequences to other undergraduates. One member of each pair of 42 undergraduates, referred to as a learner, was asked to earn points exchangeable for money and told that touching a square shown on the screen of the display monitor may or may not change points. Unlike standard operant experiments, the point change was not determined by any computer program but by responses of another experimentally naïve undergraduate, referred to as an instructor. Response rates for 15 of 21 learners were higher than those for their yoked partners, who got and lost points independent of their responding. For 17 of 21 instructors, responses to an alternative (S+ key) that produced points to the learners were more than responses to another alternative (S- key) that resulted in the learners’ point loss. Each of 16 instructors pressed the S+ key more frequently after the learner responded than after the instructor pressed the S+ or S- key. The mean interval between the learner’s response and the instructor’s S+ response was shorter than 1 s for each of 14 pairs of instructors and learners. Consistent with the behavioral principle of positive reinforcement, these results suggest that the instructors generally provided positive reinforcers depending on and immediately following the learners’ responses.