Aggression is hostile or destructive behavior that is used in an attempt to dominate. It includes behaviors necessary for human survival but also those leading to pathologic destruction. It is often unprovoked. Serial killers' actions can certainly be classified as aggressive as they are not prompted, are injurious, and are directed at mastering their victims.

Aggression can be classified into two broad categories: affective aggression and predatory aggression (Piacente 1986.) Affective aggression involves actions which are often mutilating attacks on members of the same or other species unrelated to normal prey and eating behavior, or predatory aggression. This site will center around affective aggression.

Aggression is an end product of the functions of the brain, and although it can be altered, strenthened, or weakened by environmental factors, it has as its center a complex interaction of anatomic, chemical, and physiological determinants. Pathologic aggression can therefore be evaluated in terms of its environmental provocations and its physiological provocations. Disruptions of controlling physiologic mechanisms can lead to pathologic states of aggression. These disruptions can be caused by:

Neuroanatomical Factors

Neurochemical Factors

*It is important to keep in mind that animal studies concerning violent responses are applied to human situations, as humans can not often be directly experimented on, and that these applications are tenuous because human behavior can not be consistently reproduced in animals.