Shyness can manifest on behavioral, affective, and physiological levels, but little is known about how these components cluster. We coded behavioral expressions of avoidance/inhibition, collected self-reported nervousness, and measured cardiac vagal withdrawal in 152 children (Mage =7.82 years, 73 girls, 82% White) to a speech task in 2018-2021. A latent profile analysis using these behavioral, affective, and physiological indicators revealed four profiles: average reactive (43%), lower affective reactive (20%), higher affective reactive (26%), and consistently higher reactive (11%). Membership in the higher reactive profile predicted higher parent-reported temperamental shyness across 2 years. Findings provide empirical support for the long-theorized idea that shyness might exist as an emotional state but also represents a distinct temperamental quality for some children.