Personality constructs were proposed to describe intraindividual variability in interpersonal behavior. Flux refers to variability about an individual's mean score on an interpersonal dimension and was examined for the 4 poles of the interpersonal circumplex. Pulse and spin refer to variability about an individual's mean extremity and mean angular coordinate on the interpersonal circumplex. These constructs were measured using event-contingent recording. Latent state-trait analyses indicated high stability of flux in submissive, agreeable, and quarrelsome behaviors and some stability in the flux of dominance. Further analyses indicated moderate to high stability in pulse and spin. Neuroticism predicted greater pulse, spin, and submissive behavior flux. Extraversion predicted greater flux in agreeable behavior. In contrast, Agreeableness predicted reduced spin and quarrelsome behavior flux. Social environmental variables predicted greater flux in dominant behavior. Flux, pulse, and spin provide reliable and distinctive additions to the vocabulary for describing individual differences.