Aggression and violence are themes that intrigue human beings. Despite all the development achieved by man, manifestations of brutality are still part of everyday life on all continents. In the literature, we find different theories that try to explain aggression. Defined as a complex process of responses from the animal’s endocrine and nervous systems, programmed to be triggered by a stress stimulus (^{WILSON, 1987}), aggression can be influenced by internal or external motivation factors and genetic or learned ones (^{JOHNSON, 1979}). From biology to culture the different facets of the issue do not end.

Observations about animal behavior show that aggressive behavior is present in diverse species, aiming at survival and adaptation. Disputes over territory, food, and females have been arguments to explain aggression between animals of various species, including humans. In an interesting study on the roots of human aggressiveness, ^{Goodall (1991)} states that primates fiercely defend their territories. She reports a four-year war in which a group of chimpanzees split into two subgroups. The splinter wing had to go to another territory, where they were decimated over time by members of the enemy group. Goodall portrays the hatred aroused in chimpanzees by the sight of another community member. Females were attacked more frequently, especially when unaccompanied. Peaceful contact could occur barely in adolescence when there were inter-community encounters, which made it possible for a young chimpanzee to migrate to another group.

Similarities between men and chimpanzees, such as sexual coercion and dominance, in which the male forces the female to live in a conjugal state have been reported by ^{Wrangham and Peterson (1996)}. Rape is also observed in monkeys. Among orangutans, for instance, females choose strong males, and physically less privileged adults do not have much chance of attracting a female, which makes them use force for mating. Monkeys, like men, live in social groups with hierarchy and power relations. They even fight for leadership, with descriptions in the literature of disputes between large males for status, fertilization, and control of females, ensuring reproductive success. Aggression is even more brutal when a male kills the baby of another male, demonstrating strength, as way to guarantee the fidelity of the female, who feels protected if accompanied by the father of her child.

Examining gender issues, Wrangham and Peterson argue that men are more warriors than women. They report that most societies prevented women from participating in war, as they would be more fragile and less effective. Consulting statistical data, these authors found that men commit more violent crimes than women. They discuss the patriarchy theory, concluding that Bahofen’s theory does not have solid support since no anthropological record was found supporting authentic matriarchy. Different societies are not free from violence, which is not a privilege of Western culture since Eastern culture also registers it. These authors consider patriarchy part of human biology and relate its evolutionary origins to the control of women and the need to support peers in competition with adversaries.

A fact that deserves attention is that primates are one of the few species that kill their fellow man. Most species have developed signs and rituals that highlights conflict. The strongest wins, and the other, defeated, moves away. ^{Darwin (2000)} describes signs and rituals that signal divergence and power sufficient to scare away the intruder or dissuade the weakest from avoiding confrontation. In this work, Darwin describes the posture of the human being in aggression, pointing out characteristic signs of the species that reveal fury, anger, or indignation. These signs are common around the world, with some variations. In a rage, for instance, the face turns red or purple, breathing is altered, and the body is held erect, ready for immediate action. The mouth is usually tightly closed, and the teeth grind or clench. Raising the hand with a closed fist is common. Sometimes the reaction is different. There is a tremor, and the voice gets stuck in the throat. The retracted lips expose the clenched teeth. The moods of anger and indignation differ only in degree from fury, and their signs are quite similar. In the case of irony and provocation, Darwin observed the retraction of the upper lip in such a way that the canine tooth is shown only on one side of the face.

An ethology scholar, ^{Lorenz (1979)}, raises a rather interesting hypothesis when examining aggressiveness among men: violence in primates arises partly from the development of their cognitive capacity. He believes that aggressive impulses are innate, and that man has not found an appropriate channel to express them in contemporary society. Lorenz describes inhibitions that control aggression in different social animals and that prevent them from injuring or killing their brethren and claims that there is a failure in this inhibition among humans. The imbalance caused by the human ability to develop language and abstract thinking would be a decisive factor in this matter. Humanity has evolved faster than the biological barrier against aggression. Conceptual thought and language influenced the evolution of man because they produced something equivalent to the heredity of acquired characters. Mechanisms of instinctive behavior are not up to confronting new conditions created by man, who conceived instruments to live as a compensation for not having much physical strength. However, according to Lorenz, the carnivore mentality still prevails. By developing intelligence and creating, for example, firearms and others that allow an attack from a distance, the human being was faster than the evolution of species in general, not giving time to nature to create inhibitory defense mechanisms, such as those produced by proximity to the victim. ^{Saint-Exupery (1942)}, in Pilote de Guerre, exemplifies this fact by describing his experience of throwing bombs from the plane he was piloting, hitting undetermined people whose faces he could not distinguish at the height where he was. He felt as if he were hitting ants, whose suffering he could not assess, and was therefore indifferent to them.

^{Wilson (1987)}, in turn, lists different types of aggression and states that for each species, there is an ideal level of aggressiveness, which is the minimum necessary to guarantee victory. An aggressor dedicates time to aggression that he could invest in other essential activities such as mating and caring for their offspring. Wilson indicates internal causes for the phenomenon, such as stress and hormones, and environmental causes, such as an intruder in the territory; food dispute; overpopulation, or change of season, especially spring, marked by sexual reproduction. He suggests that to decrease aggressive behavior and reduce catecholamines and corticosteroids to appropriate levels, demographic density and social systems must be considered so that aggression appears inappropriate and maladaptive.

The above-mentioned factors may lead one to think that aggression is innate and related to the species survival, being biologically determined. Other authors, however, refer to culture as a determinant of aggressive behavior. ^{Mead (1976)}, for example, describes different patterns of behavior that vary according to culture, stating that the environment induces individuals to attack each other. Education, culture, and learning would be elements that would make an individual more or less aggressive. She portrays how different cultures produce different individuals, illustrating with communities with opposing principles. She mentions the Arapesh, a community where men and women unite around a common task, primarily maternal. Gender differences are respected, prevailing cooperation, being the norm for individuals to be kind. The Mundugumor community, on the other hand, a cannibal tribe not far from the Arapesh, is characterized by being more hostile and competitive and by a spartan education, producing tough and aggressive young people.

^{Leakey (1982)} also believes cultural influence is stronger than biological one. He claims that man is a cooperative animal and that despite instincts, the flexibility of responses depends on environmental forces. An animal is territorial to protect its resources, and learning and culture play a fundamental role in this purpose. He mentions a type of behavior that can be interpreted oppositely according to the context, cannibalism. In the case of endocannibalism, it manifests love and respect as an attempt to incorporate the other and keep him or her alive. On the other hand, exocannibalism is pugnacious, being related to aggressiveness, to destroying the enemy. Leakey discusses the importance of marriage rules and the need for social and economic alliances. Exogamy, exchange, and prohibition of incest are laws that underlie culture, which makes man different from animals. Exchange and the principles that govern group life, marked by cooperation, are established from kinship relations. Thus, in his conception, before being aggressive, human beings are cooperative.

^{Pierre Clastres (1980)}, in his turn, suggests that war as inherent to “primitive” civilizations. He claims that primitive societies are violent; their social being turns to war, which has characteristics of universality. Clastres contests the naturalist discourse that assumes that aggression is a natural fact since man is a hunter and war would be a consequence of hunting. This point of view would imply the dissolution of the sociological in the biological. He also criticizes the economic discourse that considers that the primitive subsistence economy is one of misery, in which the rarity of goods would lead to armed conflict. In his opinion, primitive societies are leisure societies with no surplus. Clastres discusses political discourse, disagreeing with Levi Strauss, who considers that war would result from unsuccessful commercial transactions. He claims that these societies refuse the risk inherent in trade, as they do not want to alienate their autonomy and lose their freedom. Primitive society is a space of exchange and also of violence. The community belongs to the local group, and the territory is a political unit, an exclusive space for community rights. The relationship with neighbors is political; there is no division of labor nor production of surpluses. The community is totality and unity at the same time. The chief is deprived of power and speaks in the name of society based on ancestral law. Neighboring groups take the place of the Other as a mirror. It is a society that wants dispersion. War is a condition of life, as it affirms differences. The exchange would be identification, a threat to the unit’s autonomy. So, trade only with nearby groups; alliances depend on war.

Robin Hood personifies another kind of relationship between violence and society: social banditry. In this case, the population considers violent acts legitimate since the bandit is a hero who acts to defend the poor and oppressed. The bandit’s function is to impose certain limits on the oppression of a traditional society at the price of disorder, extortion, and murder (^{HOBSBAWM, 1970}). Social banditry gave way to politically organized movements based on ideologies like socialism. In reflecting on the relationship between violence and modernity, ^{Martuccelli (1999)} points out that violence had a positive meaning as an expression of the class struggle of the search for social justice. Violence manifests a state of irrepressible conflict in which social actors, having no other means, resort to violence to make themselves heard. Revolutions exemplify this stance. However, Martuccelli states that in modernity, the negative conception of violence prevails, synonymous with failure, with the irruption of the “primitive.” Today’s society is continuously exposed to risk, and there is a feeling of insecurity that society cannot control. According to this author, risk comes from the consequences of technical achievements in contemporary society and the complexity and implications of actions. A wrong decision can lead to risk or violent behavior. US foreign policy and terrorism seem to exemplify this situation well. Martuccelli points out the profound modern ambiguity in which the individual should be able to govern himself from within. At the same time, the precept prevails that the subject only dominates himself to the extent that he is controlled from the outside. He claims that this hidden tension, already noted by Durkheim, becomes evident and explicit. Violence thus expresses the conflict between these two realities.

Seeking to understand the phenomenon of aggressiveness with the tools of psychoanalysis, in 1920, Freud created the notion of the death drive (^{FREUD, 1976a}). In Discontent in Civilization, when dealing with aggressive human instincts, he discusses whether the progress of civilization could dominate the disturbances brought by this drive (^{FREUD, 1974}). In a letter to Einstein titled Why War? (^{FREUD, 1976b}) violence appears associated with the satisfaction of man’s destructive impulses and desires, but it also appears as a way of resolving conflicts. According to Freud, muscular strength and intellectual superiority are always linked to power, and violence would be overcome by transferring power to a larger unit, preserved by emotional links between its members. Creating a supreme authority and accepting a necessary power would be necessary for this. However, the attempt to substitute real force for ideas would be doomed to failure. Freud believes it is useless to try to eliminate man’s aggressive impulses; it is necessary to deviate from them and stimulate the life drive, Eros. Thus, he understands that everything that stimulates the growth of emotional bonds between men, such as love and identification, and everything that promotes the development of culture must operate against war.

The concept of the archetype, as developed by Jung, is quite interesting when applied to this issue, as it is a concept that allows one to escape the culture versus biology, innate versus learned dilemma. The archetype is a universal structure that appears in all cultures and manifests in a particular way through symbols. As an innate and universal pattern, it is almost an instinct, making it plausible that perhaps biological roots of aggressiveness can be identified. However, it appears in a very particular way, being able to manifest itself in the most different ways according to the context in which it appears. Maybe Mead is right. In a welcoming environment like the Arapesh community, manifestations of this archetype can be properly integrated, and aggressiveness will tend to be used creatively. The destructive aspect will be evident in hostile environments like Mudugamur communities.

Jung works with the concept of opposite poles, stating that evil is inherent in human nature, in the same way, that there is no light without shadow. The individuation process is characterized by the continuous reconciliation of opposites, represented by the union of light and dark. The development of consciousness is the possibility of dealing with these dimensions constructively. Jung speaks of an ethics inherent to the human being. The unconscious is conceived as an autonomous entity, and morality is a universal property of the human psyche. Consciousness imposes itself on the subject, demanding that the individual obey an inner voice (^{JUNG, 1993}). Jung further states that being aware of what affects the subject is the way to transform the blindness of affect into knowledge. The individual must know how he is living, understand what he is doing and hold himself accountable for his actions. In line with Lorenz’s statements, Jung states that divine power has been placed in man’s hands (he can build and shoot an atomic bomb, for example) so that he cannot remain blind and unconscious (^{JUNG, 1988}). Through awareness, inhibitory mechanisms can be developed to deal with the aggressive instinct and avoid violence. There is no point in denying, dissociating, or projecting, but recognizing man’s aggressive nature and consciously seeking and dealing with it. This is the only way to stop being a victim of himself and be able to use aggression as an adaptive force. In this sense, ^{Jurandir Freire Costa (1984)}, when discussing the subject, makes an important distinction between aggression and violence. The first may be a pure expression of instinct, with no value judgment, while the second is a desired use of aggressiveness. Thus, violence only exists in the human context, where aggressiveness is an instrument of a desire for destruction. There is an aggressive instinct that can coexist with the possibility of man desiring peace and using violence.

Finally, the media publicize violent scenes that invade homes. The paradox of modern society: violence is closer because it is more revealed, explicit, and visible, but at the same time, distant and virtual. Does the trivialization of violence generate violence? Scholars guarantee that excess exposure leads to desensitization. Studies are trying to clarify whether there is a cause-effect relationship between violence on TV and increased aggressiveness among children and adolescents (^{QUEIROZ et al., 2002}). ^{Gomide and Speranceta (2002)} describe several psychology theories that have been used in an attempt to elucidate this relationship. From the point of view of ethological theory, violent stimulation triggers anger, and this emotion triggers aggressive behavior. Zilmann states that the universal trigger of anger is the feeling of being in danger, which can be signaled not only by a direct physical threat but also by a symbolic threat to self-esteem or dignity, causing generalized adrenal and cortical stimulation, which can last hours or days, keeping the brain in readiness for the stimulus and becoming the basis on which later reactions are quickly formed (^{GOMIDE, SPERANCETA, 2002}). Stimuli present in movies and electronic games can provoke this physiological reaction. The spectator identifies with the characters, aggressor or victim, sometimes finding a channel to relieve his aggressive impulses, sometimes experiencing a series of physiological reactions corresponding to fear, being ready to react. The challenge is to suffer this stimulation, be aware of what is happening to you, and be able to act consciously, and not just out of reflex, using aggressiveness and impulsiveness.

Contemporary society is characterized by immediacy, excess of stimuli, and the speed of new technologies that lead to the virtual world. Children and adolescents in the modern world may be deprived of an important source of learning to deal with their strength and aggressiveness through concrete experiences where the object is physically present. Learning to win and lose, to overcome obstacles, to endure frustration, to persist, and to have the strength not to give up, are behaviors that are based on the strength of aggressiveness and are experienced in very different ways whether or not there is another person present. Losing to the computer differs from losing to a friend or a real opponent. Living a situation is different from seeing it in movies. These experiences are important for development and can make room for the constellation of the hero archetype. The challenge is to find everyday situations that favor interaction so that people face challenges in the concrete world, in addition to the abstract, to remember that numbers can represent things or people and that pressing buttons can cause concrete consequences. When thinking about coexisting with aggression and using it constructively, we must look for ways where it can be experienced and lived healthily. Play is essential for development. Children’s boisterous play is also observed among other mammals and forms part of adult training. Attack, retreat, flee, and learn to defend yourself. If you hurt the other, learn to apologize to repair the damage. Anyway, discover your limits and those of others, learn to negotiate, and be aware of your actions. Different from the virtual, painless, magical world, where almost everything is possible since the physical limit does not exist. In this sense, playing sports is an interesting alternative. A game is still ritualized war: two teams on the field represent a battle creatively. The pleasure of competing, of dispute, is inherent to the human being; it produces a physical sensation of well-being. The constellated hero favors that energy is directed appropriately. Otherwise, aggressiveness that cannot find a suitable channel in the external world can turn against the ego, and pathologies such as depression, drug addiction, and other impulse control disorders, so common today, prevail.