Consumer behavior offers a useful window on human nature, through which many distinctively human patterns of cognition and behavior can be observed. Consumer behavior should therefore be of central interest to a broad range of psychologists. These patterns include much of what is commonly understood as free will. Our approach to understanding free will sidesteps metaphysical and theological debates. Belief in free will is pervasive in human social life and contributes to its benefits. Evolution endowed humans with a new form of action control, which is what people understand by free will. Its complexity and flexibility are suited to the distinctively human forms of social life in culture, with its abstract rules, expanded time span, diverse interdependent roles, and other sources of opportunities and constraints. Self-control, planful action, and rational choice are vital forms of free will in this sense. The capacity for self-control and intelligent decision making involves a common, limited resource that uses the body's basic energy supply. When this resource is depleted, self-control fails and decision making is impaired.