Responsiveness to others (i.e., our understanding, validation, and support of important aspects of others) significantly contributes to positive social relationships. In the present research, we found evidence that responsiveness has motivational origins. In two experiments, participants who were approaching positive social outcomes had a higher level of responsiveness compared to participants who were avoiding negative social outcomes. A third experiment disentangled the roles of motivation and situation valence. Positive (compared to negative) social situations were associated with higher approach motivation, lower avoidance motivation, and a higher level of responsiveness. However, within a given situation, both approach and avoidance motivation were associated with a higher level of responsiveness. This association was even stronger in negative situations, suggesting that both approach and avoidance motivation might be ways of behaving responsively in potentially difficult social situations. The effects were independent of relationship closeness and partly weaker in older compared to younger adults.