There are various ways of conceptualizing compassion, including different definitions and approaches to its measurement and training. While many have been derived and adapted directly from the Mahayana Buddhist traditions, which focus on insight into the nature of consciousness, a growing number of approaches are exploring the evolutionary roots and biopsychosocial underpinnings of compassion. These approaches begin by considering the evolutionary challenges which led to the development of supporting, helping, and caring behaviors. It also highlights different pathways which gave rise to caring behavior (such as the need for parental care and receptiveness of the infant to that care, i.e., coevolution) and the transition from aggressively maintained hierarchies to care-and-share styles of group living. While the movement from caring behavior (seen in other animals) to the multitextured nature of compassion (which is uniquely human) is a complex story, research evidence has implicated a range of psychophysiological and social processes. Furthermore, when conceptualizing compassion as a motive, which like all motives relies on a stimulus-response algorithm, it is clear that different competencies underpin compassionate engagement (stimulus) and action (response), including reasoning, imagery, and empathy. This chapter provides an overview of the various systems and competencies implicated in compassion motivation.