Psychological research on behavior has waned in recent decades. One underappreciated reason for this trend is that the field lacks a general-purpose framework targeted to the study of behavior. This chapter presents one such framework, a metatheory called the I3 Model (pronounced "I-cubed model"), which suggests that all behavior emerges from a combination of three orthogonal processes. Instigation encompasses the effects of exposure to a particular target object in a particular context that normatively affords a certain behavior. Impellance encompasses the effects of situational or stable factors that increase the likelihood that (or the intensity with which) the individual experiences a proclivity to enact the behavior when encountering that target object in that context. Inhibition encompasses the effects of situational or stable factors that increase the likelihood that (or the extent to which) people will override this proclivity, thereby reducing or eliminating the behavior's enactment. According to "Perfect Storm Theory," which is derived from the I3 Model, the highest likelihood or intensity of behavior emerges when instigation and impellance are strong and inhibition is weak. The generativity and integrative potential of the I3 Model and Perfect Storm Theory are illustrated with novel reviews of the literatures on aggression and eating behavior.