Human interactions are heavily influenced by how power is distributed, making power a highly relevant variable to many scientific disciplines. In motivational psychology, it is of particular interest that individuals differ with regard to how much they desire power (neutrally defined as influence over others): some people have a stronger power motive than others. This chapter presents the evolutionary and neurobiological foundations of the power motive, introduces previous findings on how it develops and discusses several ways to measure it. Finally, the chapter will introduce behavioural correlates of the power motive, distinguishing between manipulative and supporting power-motivated behaviour.