Aggression

Aggression, in its broadest sense, is behavior, or a disposition, that is forceful, hostile or attacking. It may occur either in retaliation or without provocation. In narrower definitions that are used in social sciences and behavioral sciences, aggression is an intention to cause harm or an act intended to increase relative social dominance. Predatory or defensive behavior between members of different species may not be considered aggression in the same sense. Aggression can take a variety of forms and can be physical or be communicated verbally or non-verbally. Aggression differs from what is commonly called assertiveness, although the terms are often used interchangeably among laypeople, e.g. an aggressive salesperson. Two broad categories of aggression are commonly distinguished. One includes affective (emotional) and hostile or retaliatory aggression, and the other includes instrumental, goal-oriented or predatory aggression.[2] Data on violence from a range of disciplines lend some support to a distinction between affective and predatory aggression.[3] However, some researchers question the usefulness of a hostile vs instrumental distinction in humans, despite its ubiquity in research, because most real-life cases involve mixed motives and interacting causes.[4] A number of classifications and dimensions of aggression have been suggested. These depend on such things as whether the aggression is verbal or physical; whether or not it involves relational aggression such as covert bullying and social manipulation;[5] whether harm to others is intended or not; whether it is carried out actively or expressed passively; and whether the aggression is aimed directly or indirectly. Classification may also encompass aggression-related emotions (e.g. anger) and mental states (e.g. impulsivity, hostility).[6] Aggression may occur in response to non-social as well as social factors, and can have a close relationship with stress coping style.[7] Aggression may be displayed in order to intimidate. The operative definition of aggression may be affected by moral or political views. Examples are the axiomatic moral view called the non-aggression principle and the political rules governing the behavior of one country toward another.[8] Likewise in competitive sports, or in the workplace, some forms of aggression may be sanctioned and others not.[9] The term aggression comes from the Latin aggressio, meaning attack. The Latin was itself a joining of ad- and gradi-, which meant to step or to go. The first known use dates back to 1611, in the sense of an unprovoked attack.[10] A psychological sense of 'hostile or destructive behavior' dates back to 1912, in an English translation of the writing of Sigmund Freud.[11] Alfred Adler had theorized about an 'aggressive drive' in 1908. Child raising experts began to refer to aggression rather than anger from the 1930s.[12] Male elephant seals fighting Ethologists study aggression as it relates to the interaction and evolution of animals in natural settings. In such settings aggression can involve bodily contact such as biting, hitting or pushing, but most conflicts are settled by threat displays and intimidating thrusts that cause no physical harm. This form of aggression may include the display of body size, antlers, claws or teeth; stereotyped signals including facial expressions; vocalizations such as bird song; the release of chemicals; and changes in coloration.[13] The term agonistic behaviour is sometimes used to refer to these forms of behavior. Most ethologists believe that aggression confers biological advantages. Aggression may help an animal secure territory, including resources such as food and water. Aggression between males often occurs to secure mating opportunities, and results in selection of the healthier/more vigorous animal. Aggession may also occur for self-protection or to protect offspring.[14] Aggression between groups of animals may also confer advantage; for example, hostile behavior may force a population of animals into a new territory, where the need to adapt to a new environment may lead to an increase in genetic flexibility