People often regulate their emotions when attempting to influence other people. For example, I may try to maintain calm about what is happening to avoid making you worried, or alternatively work up my anger or disappointment to make you worry more. In both these cases, regulation of my emotion serves to regulate your emotions. This chapter focuses on both intrapersonal and interpersonal emotion regulation and their intended and actual consequences. When two people try to regulate each other’s emotions at the same time, their emotions may converge or diverge, producing increasingly compatible orientations or escalating clashes of perspective. In some case of mutual regulation, interactants may successfully achieve regulatory effects that neither individual could have achieved separately.