Research into emotion regulation (ER) has focused primarily on the intra-personal process through which we regulate our own emotions intrinsically. More recently, however, studies have begun to explore the inter-personal nature of intrinsic ER – that is, how we regulate our emotions under the guidance of others. Preliminary evidence suggests that ER might be more effective when implemented in an inter- compared with an intra-personal manner, but these findings are based almost exclusively on self-reported ratings that capture only the subjective experience of emotions. The current study therefore investigated whether this apparent superiority of inter-personal intrinsic ER could be replicated and extended to physiological measures of affective reactions – namely, various metrics of electrodermal activity. In a within-subjects design, a sufficiently powered sample (N = 146) were required to down-regulate their emotional reactions to negatively valenced images using an ER strategy they had chosen themselves intra-personally or one that had been recommended to them inter-personally. Physiological responses converged to demonstrate the greater effectiveness of inter- over intra-personal ER in decreasing negative affective reactions, despite subjective ratings suggesting that participants perceived the opposite to be true. The superiority of inter- over intra-personal ER in physiological recordings was unrelated to individuals' perceptions of their ability to regulate their own emotions, however, and so it remains to be seen if and how such benefits extend to clinical populations.