Aggression and violence are studied in a variety of disciplines. However, it is difficult to study human aggression directly, because it occurs sporadically and people often have reasons for not acknowledging or reporting it. This methodological complexity is probably reflected in the fact that each scientific discipline has its own level of analysis and develops its own set of theories and methods to explain aggression. This chapter deals with theoretical issues related to psychological approaches to aggression. Three main groups of aggression theories are examined: Psychoanalytic, drive and learning theory. The reciprocal relationship between theory, definition of aggression and study method is addressed in this chapter. Another aim is to give a critical review of definitional, methodological and theoretical strengths and shortcomings pertaining to the three historically dominant theories of aggression presented here. A final scope is to discuss the current clinical relevance of the individual theory concerning the treatment of violent mentally ill patients.
INTRODUCTIONAggression, violence, and related behaviors have been studied in a wide range of disciplines including anthropology, biology, economy, political science, communication research, history, and sociology. In the present chapter, however, the primary focus is on psychological theories of human aggression. Elements from other disciplines, e.g., biology, sociology, etc., are only addressed provided they constitute naturally integrated parts of the actual psychological theory of aggression. Important issues such as the mutual relationship between genetics and psychosocial factors, gender and age differences, and measurement issues are not dealt with unless such topics are emphasized in the individual theory.It is well known that human aggression is not an easy field to study. In this respect, the heterogeneous nature of the term "aggression" constitutes a major complicating factor. Bandura (1973) claimed that conducting research in this field was like entering a semantic jungle of ideas that span an ample range of phenomena and activities. A study in a Dutch psychiatric hospital illustrates the clinical relevance of Bandura's point very well (Finnema, Dassen, & Halfens, 1994). Finnema and co-workers interviewed nurses working in a psychiatric hospital to find out more of how they perceived and characterized patient aggression. Most of the nurses acknowledged positive as well as negative aspects of aggressive behavior. However, the descriptions of aggression varied considerably and the authors concluded that "it was not possible to formulate a general definition of aggression on the basis of the results of the study" (Finnema et al., p. 1088). One may question how the nurses managed to plan and coordinate treatment interventions in relation to aggressive incidents when they apparently were unable to share a common definition of the phenomenon. It is claimed here that the definitional issue described above illustrates a situation representative...