What happens when people experience a reduced sense of personal control? Among the various strategies to defend against a perception of randomness, people may show an increased acceptance of external sources of control. Indeed, in one of the most classic studies in social psychology, Stanley Milgram referred to an “agentic shift”—the tendency to relinquish personal control to an external agent—to explain his dramatic obedience effects. We propose that his account is a specific manifestation of a more general phenomenon: the tendency for increased susceptibility to various forms of external social influence when perceived personal control is reduced. In a series of (lab and field) studies using a variety of perceived control manipulations, we demonstrate that a reduction in the sense of personal control increases people's vulnerability to the bystander effect, promotes obedience to authority and fosters compliance with behavioral requests. Copyright © 2012 John Wiley & Sons, Ltd.