We conducted three studies to explore the antecedents and concomitants of interpersonal boredom. In Study 1, 297 subjects rated how bored they would be by an individual who performed each of 43 behaviors. A factor analysis of their ratings revealed nine behavioral factors: passivity, tediousness, distraction, ingratiation, seriousness, negative egocentrism, self-preoccupation, banality, and low affectivity. Of these, egocentric and banal behaviors were judged most boring. In Study 2 we examined the conversational styles of individuals who had been rated previously as boring or interesting. Transcripts of 52 unstructured 5-min laboratory conversations were coded using the Verbal Response Mode Taxonomy. Results showed that boring subjects used proportionally fewer disclosures (expressions of subjective information) and edifications (expressions of objective information), but proportionally more questions and acknowledgments than interesting subjects. In the third study, 72 subjects listened to three interesting and three boring conversations and then rated the participants. Subjects evaluated boring interactants more unfavorably than interesting interactants on virtually every dimension examined. © 1986 American Psychological Association.