Over the years, the research on violent and aggressive behavior has evolved from a biological basis for aggressive human behavior to attempting to use animal models of adaptive aggressive behavior to explain pathological aggression in a subgroup of the human population. This research has produced a vast database encompassing several distinct disciplines. The author proposes that there are two primary modes of aggressive and violent behavior, aggressive and predatory, which clarify and include the large array of typologies that attempt to explain this mode of behavior. The paper begins with a review of the animal research on aggression and behavior. This is followed by an examination of whether animal models of aggression have helped researchers understand aggression and violence in humans. This part of the review is divided into four areas: 1) behavioral classifications of modes of aggression; 2) bridges from ethological models to human models; 3) neuroanatomical substrates of aggression; and 4) neurochemical correlates of aggression. The next section of the paper addresses the forensic application of the research on violent and aggressive behavior. This section addresses three areas of research to which the forensic field contributes: 1) behavioral observations of individuals known to have engaged in violent acts; 2) physiological substrates of these offenders; and 3) data from special populations of criminals that exhibit distinct expressions of violent behavior. As this review has shown, nearly eight decades of research by numerous experts have produced an extensive array of literature revealing the complexity of aggression, which will contribute to its detection, control, and alleviation. References