In the near future, robotic agents might employ persuasion to influence people’s behavior or attitudes, just as human agents do in many situations. People can comply with these requests, but, people can also experience psychological reactance, which may lead to the complete opposite of the proposed behavior. In this study we are interested in the social nature of psychological reactance. Social agency theory proposes that more social cues lead to a more social interaction. We argue that this also holds for psychological reactance. Therefore, we expect a positive relationship between the level of social agency of the source of a persuasive message and the amount of psychological reactance the message arouses. In an online experiment, participants read an advice on how to conserve energy when using a washing machine. The advice was either provided as text-only, as text accompanied by a still picture of a robotic agent, or as text accompanied by a short film clip of the same robotic agent. Confirming our expectations, results indicated that participants experienced more psychological reactance when the advice was accompanied by the still picture or when the advice was accompanied by the short film clip as compared to when the advice was provided as text-only. This indicates that stronger social agency of the messenger can lead to more psychological reactance. Furthermore, our results confirmed earlier research about the effects of controlling language on psychological reactance. Implications are discussed.