The human experience of boredom is studied in relation to arousal, constraint, subjective repetitiveness, and unpleasantness. Intense boredom induced by a simple repetitive task is found to be associated with decreased arousal and increased constraint, repetitiveness, and unpleasantness. In an attempt to synthesize boredom, induction of each independent variable by means of post-hypnotic cues indicates significant effects for arousal and constraint but not for repetitiveness and unpleasantness. No single variable is found necessary for boredom although the evidence suggests that normally all 4 factors are present. Implications of findings for current boredom theories are discussed. (33 ref.) (PsycINFO Database Record (c) 2016 APA, all rights reserved)