The term violence is a popular term that conceals more than it reveals. All acts that cause property destruction, injury and death are called “violence.’ The basic problem facing attempts to understand violence is that humans have a great variety of destructive behaviors that are different. Even neuroscientists will use the term violence indiscriminately or will suggest a simplistic classification that has little biological basis. For example, one research group tried to relate violence to a gene that creates the brain enzyme, monoamine oxidase. They suggested that there are two kinds of violence: impulsive, reactive violence and predatory violence. I would suggest that there are more kinds of violence. No single gene and no single system in the brain will be isolated as the “cause of violence.”
Humans get angry and fight. Angry humans are violent in different degrees with different consequences. Fighting assumes many forms. Hitting, punching, scratching, kicking, biting are all different behaviors used in fighting. Nice, smart people living in affluent communities are tempted to believe that that violence is an aberration and that humans kill because they are abnormal, sick or unduly provoked. They do not realize that violent behaviors are innate, dominant features of human existence.
In my community, people are relatively well behaved and killing is rare. Family violence is common. Violent acts are not aberrations but are a constant feature of human existence. Humans injure and kill other humans for pleasure and profit and killing on a large scale represents the intelligent and systematic application of knowledge, skills and discipline. The art and technology of war has been practiced, recorded, and honored by every society that has flourished on planet earth. In the mind of a pragmatic warlord, victory goes to the side that kills the enemy swiftly and decisively. Hesitation is weakness and surrender is cowardice.
Humans are Predators
Human males are natural predators they kill to eat, but also use their predatory tendencies to kill for other reasons. Killing is a native life skill that is carried out with skill and deliberation. With remote controlled weapons, the most lethal acts can be launched by humans who have no experience of violence. Weapons systems are evolving into networked extensions of human brains. Modern warriors fight with smart weapons and unmanned aircraft that can be remotely controlled by pilots sitting safely at workstations close to home. Hopeful idealists imagine a nonviolent world with altruistic information sharing. While I can imagine a nonviolent world, the reality is that this utopian state is impossible.
Arousal, Action, Reaction System (SNS)
The autonomic nervous system is a basic regulator of social behavior. Activating the parasympathetic system tends to pacify. Activation the sympathetic nervous system leads to fight or flight, anger and destruction. The SNS is a complex network arranged much like the peripheral nervous system with segmental spinal cord roots with ganglia in the thorax and abdomen. The adrenal gland is a peripheral resource that secretes epinephrine, norepinephrine and steroid hormones on command from the brain, flooding the blood stream with activation messages that reach all tissues. The SNS also commands other glands that secrete hormones. Some of the effects of SNS activation are: pupils dilate, sweating increases, blood flow to muscles increases, breathing and heart rate increases, blood pressure increases, digestive activity slows or stops. You become angry and aggressive or fearful; sometimes all SNS effects combine to produce confusion, panic and fighting. The SNS creates strong feelings in consciousness. You may be quietly enjoying dinner with friends until someone insults you. Within seconds, your SNS activates flight and fight and fight" responses and you become angry. Your upset may last for hours or days and you may never forgive the person who insulted you. The memory system gives the highest priority to storing features of events that trigger strong SNS arousal.
Anger is the dominant human emotion. Anger is disruptive and can be dangerous. Anger is expressed by noisy displays and attacks. All human interactions are influenced by the threat of anger and much brain power is devoted to anger management. Anger is an old animal program that emerges from the reptilian brain - the lizard rises up hisses and attacks. The human rises, threatens with gestures and then, optionally, attacks. Anger energizes aggressive behavior and is both protective and destructive at the same time. Anger has several stages expressed at different levels of intensity. Often anger intensity escalates from threatening behavior to all-out attack. The victor in a dispute intimidates his opponent who either submits with conspicuous supplication behavior or is attacked. Anger progresses to fighting.
Combatants are injured or killed in a fight. Fights leave body scars, accounts to be settled and long-lasting memories that facilitate future fighting. Anger is a pure and fundamental emotion that is preprogrammed in the amygdala. Human children get angry as infants when they are hungry or uncomfortable and do not achieve immediate satisfaction. The term “frustration” refers to an angry outburst that arises when seeking behaviors are blocked short of achieving the desired goal. Infants and young children demand instant gratification of their needs and are easily frustrated. An essential part of social maturation is learning to tolerate delays in gratification of basic drives. Children get angry often during the day and sometimes display alarmingly violent thoughts and behaviors. Anger is a daily feature of sibling interaction and is common in unsupervised children's play.