Eight studies by Professor Adam Galinsky and colleagues find a robust negative relationship between the experience of power and the experience of loneliness. The researchers establish a key mechanism that explains this effect, demonstrating that the need to belong mediates the effect of power on loneliness. These findings help explain some effects of power on social cognition, offer insights into organizational well-being and motivation, and speak to the fundamental question of whether it is “lonely at the top” or lonelier at the bottom.