aggression
n. behavior aimed at harming others physically or psychologically. It can be distinguished from anger in that anger is oriented at overcoming the target but not necessarily through harm or destruction. When such behavior is purposively performed with the primary goal of intentional injury or destruction, it is termed hostile aggression. Other types of aggression are less deliberately damaging and may be instrumentally motivated (proactive) or affectively motivated (reactive). Instrumental
aggression involves an action carried out principally to achieve another goal, such as acquiring a desired resource. Affective
aggression involves an emotional response that tends to be targeted toward the perceived source of the distress but may be displaced onto other people or objects if the disturbing agent cannot be attacked (see displaced aggression). In the classical psychoanalytic theory of Sigmund Freud, the aggressive impulse is innate and derived from the death instinct, but many non-Freudian psychoanalysts and most nonpsychoanalytically oriented psychologists view it as socially learned or as a reaction to frustration (see frustration–aggression hypothesis). See also pathological aggression. Aggression among nonhuman animals also exists, involving direct physical attack by one on another or the threat of such attack. Over the years, different researchers have identified different types of animal aggression based on such considerations as the members involved (e.g., intraspecific or interspecific),
the apparent intent (e.g., offensive or defensive), or the stimuli eliciting them. One of the most influential classification schemes has been that proposed in 1968 by U.S. physiological psychologist Kenneth Evan Moyer (1919–2006). It describes predatory aggression to obtain food and the converse antipredatory aggression, territorial aggression to repel intruders from an area, intermale aggression against a competitor, fear-induced aggression, irritable aggression in response to pain or deprivation of an item required for survival, sexual aggression to secure mates, maternal aggression to protect young offspring, and instrumental aggression. See also dominance aggression. —aggressive
adj.