Emotion regulation (ER), which refers to the ability to identify, experience, modulate, and express emotions, is critical to adaptive functioning. Although the term ER has been used synonymously with coping strategies, affect regulation, and self-regulation, it is important to differentiate ER from these other constructs to ensure optimal construct validity and accurate measurement. To this end, ER has been defined as "the process by which individuals influence which emotions they have, when they have them, and how they experience and express these emotions" (Gross, 1998 p. 275). Emotion is experienced in three primary ways: behaviourally, physiologically, and experientially (Gross, 1998); therefore, ER refers to strategies that alter these three aforementioned emotional processes. This book discusses the processes, cognitive effects, and social consequences of emotion regulation.