Incompatibilists and compatibilists (mostly) agree that there is a strong intuition that a manipulated agent, i.e., an agent who is the victim of methods such as indoctrination or brainwashing, is unfree. They differ however on why exactly this intuition arises. Incompatibilists claim our intuitions in these cases are sensitive to the manipulated agent’s lack of ultimate control over her actions, while many compatibilists argue that our intuitions respond to damage inflicted by manipulation on the agent’s psychological and volitional capacities. Much hangs on this issue because manipulation-based arguments are among the most important for defending incompatibilist views of free will. In this paper, I investigate this issue from a experimental perspective, using a set of statistical methods well suited for identifying the features of hypothetical cases people’s intuitions are responding to. Results strongly support the compatibilist view—subjects’ tendency to judge that a manipulated agent is unfree was found to depend on their judgments that the agent suffers impairments to certain psychological/volitional capacities that compatibilists say are the basis for free will. I discuss the significance of these results for the use of manipulation cases in the philosophical debate about free will.