Aggression: Psychological Theories

Aggression has been defined as the intention and the attempt to unduly control, harm, or destroy another individual by physical, social, emotional, or psychological means. This definition applies to aggression toward objects as well. Aggression can be active or passive; direct or indirect; and verbal or physical. Moreover, it can be carried out in an overt or covert manner. The words aggression and violence are often used interchangeably, but they actually have different meanings. For example, one can be aggressive and not be violent, yet a person who is violent is also being aggressive. Thus, aggression is the key ingredient in all violent actions. For the purpose of this entry, the type of aggression discussed herein is the type related to criminal violence.

Historically, aggression has been part of human nature and has been viewed from an evolutionary perspective as adaptive. Some argue that aggression represents a biologically or genetically programmed set of responses. However, if this were truly the explanation for aggression, the rates of violence across cultures, nations, and races would be more congruent. The view that aggression and violence are explainable by psychological factors provides a more workable foundation from which to build an understanding of its potential causes.

It is not to be discounted that aggression seems to have a relation to biological or genetic substrates, as well as more largely based sociological factors, for these likely contribute to the survival of the species. However, aggression and violence are not inevitable events in life. Thus, the psychological factors related to the aggressive and/or violent individuals reside as the mitigators of action. Aggressive and/or violent behaviors, like all other behaviors, are choices in which the perpetrator chooses to engage.

There are two types of aggression, hostile/expressive and instrumental. They are distinguished by the expected goals, or motivations, of the perpetrator of such acts. Hostile/expressive aggression is generally perpetrated in reaction to some form of anger-inducing situation, which could be in the form of a personal failure, an insult, or an actual physical assault. The use of hostile/expressive aggression has one goal: to make the victim(s) suffer. Hostile/expressive aggression is characterized by intense and individually disorganizing anger within the perpetrator.

Instrumental aggression, on the other hand, has its genesis in competition and desires on the part of the perpetrator, which may relate to objects, status, or both that are in the possession of others. Harm may be perpetrated toward the possessor, the object, and/or status themselves. However, even in cases in which harm toward the possessor of the object/status may [Page 15]not be intended, the perpetrator's perceived need to obtain or destroy what the victim has (and they have not) will lead them to engage in aggressive actions to accomplish their goal, regardless of the cost.

Several theories, or models, have been offered to explain aggression from a psychological perspective. Some of these have a degree of overlap with sociological or biological theories but are nonetheless predominantly psychologically driven.