To vicariously condition either fear or a positive emotional response, films in which a 5-year-old male model manifested one or the other response were shown to nursery school children. The measure of vicarious conditioning was the children's rate of response to the conditioned stimulus and a controlled stimulus in several operant situations after watching the film. In Experiments 1 and 2, fear responses were vicariously conditioned; after viewing the film, the children rated lower in operant responses to the fear stimulus than to the control stimulus. In Experiments 3 and 4, after viewing a positive film, the children showed a higher rate of operant response to the positive emotional stimulus than to the control stimulus. The experiments show that human operant responses can be affected by both vicarious fear conditioning and vicarious positive emotional conditioning. In all experiments the conditioning effect was short term and easily neutralized. Further research suggested includes: consideration of the age factor; use of live models rather than films; and reduction of experimenter bias, expectations, and generalization by employment of automated apparatus and maximally different test stimuli. References and appendix are included. (AJ)