Speech and heart rate were continuously monitored during 7 days from morning to evening in 41 Grade 2 children selected for high or low parental judgments of sociability and shyness. Children attended school in the mornings and were free in the afternoons; the child's social situations in the afternoon were reconstructed with the child and a caretaker. During the afternoons sociable children spent more time in conversations than unsociable children, but the groups did not differ in their verbal participation within conversations. Shy children spent as much time in conversations and spoke as much in familiar situations as nonshy children but spoke less in moderately unfamiliar situations. Neither sociability nor shyness had an effect on heart rate reactivity. The results show that sociability affects the exposure, and shyness the reactivity, to situations and that these traits are clearly distinct despite some similarity in lay judgments of personality.