Aggression, as a variable of psychological study, has the hallmarks of a deeply ingrained personality trait. It is related to genetic and physiological factors; it emerges early in life but is influenced and shaped by a chilďs life experiences; it is consistently associated with gender and is stable or predictable over time and across situations. However, it does not follow that aggression must be viewed as a drive. On the contrary, in this article we argue that aggression is best represented internally as a collection of specific 'scripts' for social behaviour, emphasizing aggressive responding, and the associative structure relating these scripts to each other, to external cues, and to outcome expectancies. The construction and maintenance of these scripts obey well-understood principles of human information processing. Once established, these networks of scripts may be extremely resistant to change. The result is a set of cognitive structures that promote consistent forms of instrumental and hostile aggression over time and across situations.