Social interactions often involve one person responding to another’s goals or experiences. The nature of these responses vary across interactions. We can help others or hinder them; we can empathize with others or not. As observers, people reason about such social responses as products of both individual dispositions (e.g. “She is nice”) and interpersonal relationships (e.g. “They are friends”). In this talk, I will present experiments that test how human infants and children reason about relationships and dispositions as causes of social behavior and emotions. The results suggest that humans possess an early developing ability to learn about specific relationships and use them to predict both helping behaviors and empathic emotions.