On the violence inhibition mechanism or why, even though normally people have a strong inner resistance to harming others, some find it easy to commit violence and even kill, and how to solve this problem

When it comes to violence, although it seems to be a socially unacceptable phenomenon, its naturalness is most often not questioned, considering the fact that we can observe it in the animal world and human society. However, if we study this phenomenon more deeply, we can easily realize that things are not so simple, especially in the case of intraspecific interactions.

Did you know that in the nervous system of many animals and even humans, there is a mechanism that, when activated, inhibits offensive aggression towards members of their own species while not affecting defensive behavior or other forms of activity? The theory that many species have inhibitions of intraspecific aggression has existed for quite a long time, since the very emergence of ethology, which is the science of animal behavior. In many cases, and especially when members of the same species have strong innate weapons and no opportunity to avoid each other, unrestrained forms of aggressive behavior reduce the aggressor's own chances of survival and reproduction. This is how aggression inhibitions that prevent the infliction of harm, often through the ritualization of intraspecific fights, emerge during biological evolution.

Similarly, humans have the violence inhibition mechanism. It is based on an innate reflex that causes an aversive reaction when observing the suffering of others. Also, the functioning of this mechanism explains the development of empathy and different aspects of morality, and its dysfunction explains the emergence of psychopathic tendencies, which, according to a huge number of criminological studies, are the purest and the best explanation of antisocial and violent behavior, especially in the case of premeditated acts of harming people. A lot of evidence, including the findings of anthropologists and military experts, suggests that the average and healthy individual has a strong inner resistance to killing other people. The concept of the violence inhibitor is also supported by research from the fields of psychiatry, neurophysiology, and genetics.

In turn, the prevalence of violence we observe can be explained by the fact that even a relatively small number of individuals who can easily commit it are capable of causing significant harm to other people and society. The truth is that violence is nothing more than a deviation and pathology, and we will get acquainted with all the details and evidence behind such a conclusion. Also, we will develop potential solutions to the problem of still-existing violence in society and human relationships.

You can view a brief presentation of the most important ideas published on this website or continue reading here to learn all the details immediately.

▶ Main discussion of the website (free discussion on the problem of violence in human society)

In order to study the topic of violence as a form of behavior and social communication, we need to give this concept a concrete definition. Moreover, we will often use the concept of psychopathy, and we must be clear about which state of the human psyche it describes.

In defining the concept of violence as well as another important concept of self-defense, we will start with the broader concept of aggression. An ethological approach will help us solve this problem. To be clear, we should first understand what aggressiveness is. It is a feeling of hostility that arouses thoughts of attack or simply a natural disposition to be hostile^[1]. In turn, aggression is a disposition to behave aggressively, hostilely, and unfriendly^[2].

However, functional (or adaptive) aggression as a form of behavior and social communication in intraspecific relationships is characterized by constrained actions, reactions, and social signals between participants in the conflict. It is important to pay attention to this “constraint.” It consists of rules and rituals of a certain magnitude, expression, and sequence, which make aggression functional, dynamic, yet structured behavior within inhibitory limits. Regardless of species-specific rules, these components are necessary for functionally driven aggression^[3][4][5]. Also, such inhibition of aggression is the main function of the violence inhibition mechanism, which we will discuss later.

The difference between violence and functional aggression lies in the behavioral sequence or interaction dynamics between two or more conspecifics in combat. Violence is characterized by the absence of inhibitory control and the loss of adaptive functions in social communication. As a quantitative behavior, violence is an escalated, pathological, and abnormal form of aggression characterized primarily by short attack latencies and prolonged and frequent harm-oriented conflict behaviors. As a qualitative behavior, violence is characterized by attacks that are aimed at vulnerable parts of the opponent's body and context-independent attacks regardless of the environment or the sex and type of the opponent^[3][4][5][6].

It is believed that functional aggression, unlike violence, is not anticipated to target vulnerable body parts even in the midst of an agonistic interaction unless challenged, as seen in defensive aggression^[4][7].

According to the threat superiority effect, humans (like many species) have the ability to quickly and effectively detect threats in the environment, which allows them to activate defense mechanisms in time and adequately respond to the threat. Such a response can be expressed by flight or defensive aggression (it is also called a fight-or-flight response). Threat stimuli can be innate due to the fact that humans have encountered them in the course of biological evolution (for example, snakes) or acquired through experience due to the adaptation of defense mechanisms (for example, a knife or a gun). Threats can be conveyed through many visual or auditory modalities, but in human interactions, they are often indicated through angry facial expressions^{[8][9][10][11]}.

Self-defense can be defined as a form of aggression performed in the presence of a threat in the environment and social signals^{[Author's note]}. Also, in the case of intraspecific relationships, self-defense (or defensive aggression) is defined as a form of aggressive behavior performed in response to an attack by another individual. It is worth noting that extreme forms of defensive aggression can have violent characteristics. However, it is distinctly different from offense in terms of its behavioral expression and inhibitory control^[12][13].

In studies of the human psyche and behavior, the division of aggression into reactive (affective) and proactive (instrumental) forms is widespread. Reactive aggression is an impulsive response to a perceived threat or provocation associated with high emotional arousal, anxiety, and anger. In turn, proactive aggression is instrumental, organized, cold-blooded, and motivated by the anticipation of reward^[14][15].

In other words, reactive aggression arises as a reaction of the subject to a certain stimulus (including a threat stimulus that can lead to self-defense) or as a result of frustration. It is limited to a specific conflict, has no intent, and no purpose other than the direct infliction of harm. In turn, proactive aggression consists in achieving a certain positive result by resorting to aggressive actions; it is a planned and motivated act of harming the victim.

Also, it is important to note that proactive aggression is significantly associated with reduced levels of both cognitive empathy, which is the ability to understand the emotions of others, and affective (emotional) empathy, which is the ability to experience the emotions of others^[15][16].

Psychopathy is a socially devastating personality disorder defined by a constellation of affective (emotional), interpersonal, and behavioral characteristics, including egocentricity, manipulativeness, deceitfulness, lack of empathy, guilt or remorse, and a propensity to violate social and legal expectations and norms. Psychopaths are intraspecies predators who use charm, manipulation, intimidation, and violence to control others and to satisfy their selfish needs. Lacking in conscience and in feelings for others, they selfishly take what they want and do as they please, violating social norms and expectations without the slightest sense of guilt or regret^[17].

Psychopathy can be divided into primary and secondary factors. Although both factors are associated with antisocial behaviors, hostility, and reduced empathy, primary psychopathic traits predominantly reflect interpersonal and affective characteristics such as grandiosity, manipulative behaviors, superficial charm, a lack of remorse or guilt, and emotional detachment. In turn, secondary psychopathic traits refer to features often portrayed by individuals who are irresponsible, impulsive, incapable of long-term planning, and display erratic behaviors^[18].

As we will see later in the third topic of Chapter Two, individuals with high scores of primary psychopathy include managers and CEOs who succeed by deceiving, manipulating, and unfairly exploiting others, police and army officers who commit crimes against humanity (mass arrests, tortures, and murders), and politicians who establish authoritarian and oppressive regimes. In turn, ordinary violent offenders are characterized by significantly increased scores of both psychopathy factors. And their highest scores are observed in the most violent criminals, such as serial sexual murderers.

▶ Discuss the topic "Definition of important concepts"

In this chapter, we will look at the various myths about violence that prevent a full understanding of its nature and the facts that will help us understand it. As ethological, archaeological, anthropological, criminological, military, and other evidence demonstrates, violence, and especially killing, is largely absent from intraspecific animal and human relationships. The average and healthy individual has a strong inner resistance to killing, but the minority of killers is still enough to cause significant harm to everyone else.

A study of 1024 mammalian species showed that only about 40% of them were observed to have at least occasional lethal violence, that is, cases of deaths of individuals from aggressive actions by members of their own species (including infanticide, cannibalism, and intergroup aggression). Of course, this figure may be underestimated due to the lack of data, but even after adjusting for this probability, non-violent intraspecific relationships are still common and prevail over violent ones, especially if we take into account that, according to overall statistics, lethal violence is the cause of death in mammals in only 0.3% of cases^[19].

Many researchers have come to the conclusion that most intraspecific aggression is non-lethal, and individuals with techniques that enable them to avoid agonistic situations involving serious possibilities of defeat or injury are evolutionarily successful. Also, restraints against harming and killing conspecifics are common in animals that have strong innate weapons and lack the opportunity to avoid members of their own species^{[20][21][22][23][24][25][26]}. A detailed description of examples of such restraints and why they have developed during biological evolution can be found in Chapter Three.

As for the relationship of territoriality and social behavior with lethal violence, in both cases, there was an elevated level of it, which is easily explained by the increase in the number of conflicts due to more frequent social contacts and territorial fights. However, even for social and territorial species, the overall level of lethal violence is only 0.8%. Of course, against the background of other mammals, primates stand out with an increased level of violence. However, even in their case, the overall level of lethal violence is only 2.3%^[19].

It is important to note that the natural cruelty of chimpanzees is often greatly exaggerated (as in the works of primatologist and anthropologist Richard Wrangham) when, in fact, much of their violence is explained by disturbances caused by human intervention in their habitat. There is no significant evidence that chimpanzees have an innate disposition to kill conspecifics^[27][28][29]. And the closest human relative, the pygmy chimpanzee (bonobo), is widely known for its non-violent nature and complete absence of intraspecific killings^[30].

The highest levels of lethal violence are observed in lemurs, marmosets, and suricates, in which case they can reach almost 20%^[19]. However, such cases are an extreme exception, which means we can safely assume that across many species, nonkilling is the default and killing is the exception, the oddity, the unusual^[25].

It is a common claim, taken from the works of scientist Steven Pinker, that in the past, 15% of the population of hunter-gatherer tribes died from lethal violence, and in some cases, its level could be as high as 60%. Thus, societies that existed before the emergence of agricultural civilizations with cities and monopoly governments suffered from chronic violence and endless wars^[31][32].

However, a study examining 600 human populations shows that only 2% of people have been killed in all of human history, and this includes cases of war and genocide^[19]. In the case of hunter-gatherer tribes of the past, the level of lethal violence was also only 2%^[33]. Some studies argue that the presumed universality of warfare in human history lacks empirical support, and the evidence for its commonality in prehistoric times (such as that demonstrated in “War Before Civilization: The Myth of the Peaceful Savage”) may be overstated and misleading^[34][35]. As anthropologist Brian Ferguson writes, considering all the archaeological evidence for Europe and the Near East, and not just selected cases of violence, one can conclude that the idea that 15% of the prehistoric population died from war is not just false, it is absurd. And there is no evidence that war is an expression of innate human tendencies or a selective force driving human psychological evolution^[32][36].

Pinker ignored much of the archaeological evidence that did not align with his argument. One survey of 2000–3000 remains found in France showed that 1.9% of them had projectile wounds, including healed ones. Another survey of 350 remains found in Britain showed that about 2% of them had identifiable trauma. One more survey of 418 remains found in Serbia and Romania showed that 2.3% of them had signs of violent injury. A study of 2500 adult remains found in Japan showed that 2% of them had signs of potentially violent death. Anthropologist Ivana Radovanovic has looked at 1107 remains from Europe, including all of the cases on Pinker's list, and concludes that you could average out at 3.7% for a low estimate of the level of lethal violence and 5.5% for a high estimate. These results are not even close to Pinker's 15%^[36][37][33].

Claims about extremely high levels of lethal violence in prehistoric people are often based on an analogy with the high levels of it in some modern hunter-gatherer tribes. However, a study of 21 nomadic tribal societies shows that in 10 of them, only one person committed killings, and in 3 of them, there was no killing at all. Nearly half (47%) of the killings occurred in the Tiwi tribe from Australia, which shows its exceptional propensity for violence. Also, anthropologist Douglas Fry, after studying the anthropological literature, found as many as 70 nonwarring cultures, including cases of completely non-violent tribes, famous examples of which are the Paliyar (or Paliyan) from South India and the Semai from Malaysia^[33][38][39]. In addition, a study of 590 societies from all over the world found that the majority (64%) of cultures are nonwarring or unwarlike. Of course, even nonwarring societies can defend themselves against attacks, but the initiation of war is common to only a minority of cultures^[38][40]. And although homicide rates vary tremendously from one society to the next and also change over time within the same society, the vast majority of people never kill or attempt to kill anyone^[26].

What also turned out to be false was the claim made by anthropologist Napoleon Chagnon, who studied the Yanomami tribes and is often cited by Pinker, that in tribal societies, men who commit killings should be more reproductively successful (have 3 times as many children) as they eliminate their neighbors from procreation. And since, in the past, all people lived in tribes, this allegedly made a human a natural-born killer. However, the study that makes such a claim has methodological flaws; the difference in the average age between the killers and non-killers studied was more than 10 years, which distorts the result. And even if they were the same age (Chagnon insisted that they were but flatly refused to provide evidence for this), other anthropologists' calculations suggest that such a result would still be exaggerated. Also, it does not agree with the findings of other studies, which show that killers not only have the same number of children as non-killers (and the most bellicose among them have even fewer) but that the children of killers are less likely to reach reproductive age^[26][41][42].

It is worth briefly mentioning the issue of cannibalism. It turns out that researchers often mistake cases of ritual consumption of dead relatives (endocannibalism) for cases of consumption of enemies defeated in a war (exocannibalism)^[43][36]. Also, the discovery of human remains with marks presumably indicating that they were killed for consumption may, in fact, be explained by attacks by predatory animals or burial practices (in some cultures, this process involved separating the flesh of the deceased from the bones)^[27].

An analysis of 22 studies with 29 unique samples of homicide offenders from 6 countries (USA, Canada, Sweden, Finland, Germany, and Brazil) shows that the mean murderers' psychopathy score on the PCL-R test is 21.1 out of 40. At the same time, for people who do not commit crimes, it is only 5.2^[44]. In general, the majority of the population (more than 80–90% of people) demonstrate no or only a few psychopathic traits and associated behaviors. And only 1–2% of people have high psychopathy scores (above 12 out of 24 on the PCL:SV test)^[45][46].

In one study of 98 forensic men charged with violent crimes, the mean PCL-R score was 21.4. Only 9 individuals (9.2%) among them had scores below 10^[47]. For 636 homicide offenders on death row in California, the mean PCL-R score was 23.31. Only 15% of them scored 10 or less, and these individuals had no official criminal history prior to their capital crimes, were contrite, apologetic, and remorseful during their court proceedings, and generally engaged in normative conduct for the majority of their adult lives. These are people who most would view as “salvageable.” In contrast, individuals with higher psychopathy scores clearly exhibited problem behaviors. And among the five individuals who scored a maximum of 40 points were the most violent criminals, i.e., serial sexual murderers^[48].

Clinical psychopaths, scoring from 25–30 on the PCL-R test and from 18 on the PCL:SV test, make up no more than 1% of people in society. However, among incarcerated criminals, they can be as high as 25%. It has also been found that if people are divided into two equal groups based on their PCL:SV scores, individuals in the higher-scoring group will be 10 times more likely to commit violent crimes^[49]. The economic burden of crime resulting from psychopathy was up to 7.4% of GDP in the case of the United States as of 2020, and the individual suffering and loss inflicted by psychopaths on others is so enormous that it is likely impossible to estimate^[50][51].

An increased number of psychopathic individuals may show up in some professions, for example, managers and CEOs. According to various studies and claims, between 3% and 21% of their representatives are psychopaths^[52][53]. Also, one study conducted among employees of companies showed that if a company employs non-psychopathic managers (whose psychopathy scores are less than 9 out of 16 on the PM-MRV test), the overwhelming majority of employees (89.3%) will assess its activities as socially responsible and environmentally friendly. However, this figure drops to 66% in the presence of dysfunctional managers (whose psychopathy scores are 9–12) and to 52.5% in the presence of psychopathic managers (whose psychopathy scores are more than 12). In addition, the majority of employees (79.6%) think that a company shows commitment to them if it has non-psychopathic managers, but this figure drops to as low as 23.7% if psychopathic managers are present. In general, it is a widely known fact that psychopathic individuals working in companies are prone to white-collar crime, such as embezzlement and fraud. They also tend to neglect information security measures. Their actions can often even lead to the company's bankruptcy. These results demonstrate the importance of the problem of corporate psychopaths, who may make ethically questionable decisions in pursuit of their own benefit and have a negative impact on their company and society as a whole^{[54][55][56][57]}.

Politicians cannot be expected to do well either; despite the lack of reliable statistics, practically any expert in the field of sociopathy/psychopathy/antisocial personality disorder would not dispute that there is a higher percentage of individuals with psychopathic tendencies among them than in the general population^[58]. The mean PCL-R score among army and police officers convicted of crimes against humanity (mass arrests, tortures, and murders) is 21.06. Not only that, they do not have as high scores of secondary psychopathy (which is characterized by impulsivity) as ordinary violent offenders, but they have extremely high scores of primary psychopathy (which is characterized by callousness and lack of empathy). State violators of human rights have an extreme disposition for self-serving, callous, and ruthless treatment of others without guilt or remorse^[59]. Psychiatrist Andrew Lobaczewski explains the very emergence of authoritarian and oppressive regimes as the result of the seizure of political power by primary psychopaths^[60]. Also, in the case of police officers, primary psychopathic traits may be associated with the use of unjustified and excessive force against criminal suspects^[61].

Committing indirect violence, which involves using social manipulation instead of direct physical attack to harm people, also has a significant association with psychopathic tendencies^[62]. Psychopathy is also a key factor in the perpetration of intimate partner violence^{[63][64][65][66]}. And the higher an individual's psychopathy scores, the more likely they are to become violent as a result of substance use (alcohol, cannabis, and cocaine)^[67]. In addition, psychopathy is a significant risk factor in aggressive religious radicalization and a propensity for extremism (support for the use of violence in achieving political goals)^{[68][69][70][71][72]}. And its primary factor significantly predicts an individual's propensity for totalitarian political ideology, expressed by a high need for government-imposed social regulation, acceptance of life under dictatorship, denial of individual freedom, and support for oppressive methods and procedures^[73].

Criminologist Matthew DeLisi concludes that psychopathy is the purest and the best explanation of antisocial behavior and can be labeled as a unified theory of crime^[74]. It is the most formidable risk factor for antisocial behavior, crime, and violence, and no study exists that has found that psychopathy was unrelated to crime and various aberrant conduct^[75]. Also, it is worth noting that the more psychopathic an individual is, the more proactive (instrumental) aggressive behavior can be expected in the crimes they commit. As research demonstrates, committing just one act of proactive violence is already associated with increased psychopathic tendencies of the offender compared to offenders whose actions were reactive (impulsive) or non-violent (as in the case of theft) and non-offenders^{[76][77][78][79]}.

▶ See also: How large-scale or political evil arises; The problem of indirect violence; The costs of psychopathy to individuals and society; The relationship of extremism and radicalization to psychopathy and other socially negative personality traits

Military experts have found that most humans possess an intense resistance to killing. The resistance is so strong that, in many circumstances, soldiers on the battlefield will die before they can overcome it. In general, there is only 2% of the male population that, if pushed or if given a legitimate reason, will kill without regret or remorse^{[80][81][82][26]}. And we will now familiarize ourselves with the range of evidence behind such a conclusion. Also, along the way, we will examine the criticisms it faces and demonstrate their untenability.

A study by neurologists Roy Swank and Walter Marchand, published after World War II, demonstrated that after 60 days of ongoing battles, 98% of surviving soldiers are psychologically traumatized, and only less than 2% of them who are predisposed to be “aggressive psychopaths” are not affected by such a problem since they apparently do not experience any resistance to killing^{[83][80][81][82]}. Current research also confirms that some traits of primary psychopathy (which is characterized by callousness and lack of empathy) may protect an individual from experiencing psychological trauma as a result of participation in combat^[84][85]. And according to American military journalist, Brigadier General, and historian Samuel Marshall, only 15–20% of American soldiers fired at enemy positions during World War II. In many cases, those who did not fire were willing to risk great danger to rescue comrades, get ammunition, or run messages^[80][86].

It is worth noting that Marshall's conclusions are sometimes criticized. However, as American publicist and former Lieutenant Colonel Dave Grossman writes, the U.S. Armed Forces have widely accepted them. Although Marshall's methodology may not meet rigorous modern standards, that does not mean he lied, and every available, parallel, scholarly study validates his basic findings. In support of his words, Grossman cites such war researchers as Charles Ardant du Picq, John Keegan, Richard Holmes, and Paddy Griffith. The evidence they and many other researchers provide (some of which we will review after dealing with the criticism) is compiled in his book “On Killing: The Psychological Cost of Learning to Kill in War and Society,” which is on the curriculum of many American institutions. According to Grossman, in the realms of criminal justice, psychology, sociology, and peace studies programs, the possible existence of an innate resistance to killing, in most healthy citizens, is widely accepted^[80][87][88].

There is some criticism towards Grossman as well. For example, his idea that video games make people more violent and train them to be killers has been shown to be unfounded. And his promotion of military training for police officers, including training them to kill, has been criticized for the fact that it could lead to more police violence against ordinary citizens^{[89][90][91][92][93]}. But none of this is relevant to the current topic. Grossman may be a controversial person who is wrong about some things, but his position on the existence of resistance to killing is well-founded^{[Author's note]}.

Another criticism worth mentioning is put forward by anthropologist Michael Ghiglieri. He is a proponent of the idea that humans have an instinct to commit murder, rape, and genocide, developed over millions of years of evolution. And those who argue otherwise, including Grossman, in his opinion, simply do not understand biology. However, in a review of his book “The Dark Side of Man: Tracing the Origins of Male Violence,” anthropologist Brian Ferguson writes that it is full of arguments by analogy, sweeping generalizations, and one-sided presentations. It also puts forward major misinformation that is inconsistent with the literature on the topic of violence, according to which the decision to kill in men is triggered by just one chemical, testosterone. However, Ferguson praises Ghiglieri for skillfully writing his book to convince people already primed to believe men are bad to the bone^[94][95]. Now, having dealt with the criticism, we can continue to explore the topic of resistance to killing.

Back in the middle of the 19th century, French army officer and military theorist Charles Ardant du Picq conducted his own research, a survey among other officers, who told him that many soldiers simply shot in the air without aiming^[96]. Military historians John Keegan, Richard Holmes, and Paddy Griffith analyzed data on the firing performance of 18th- and 19th-century soldiers and showed that at the average combat ranges of that era, the killing rate should have been hundreds per minute, but in reality, only one or two killings occurred. The weak link between the killing potential and the killing capability was the soldier who, when faced with a living opponent instead of a practice target, simply fired over his head. Only a small percentage of soldiers were actually attempting to shoot at the enemy^[97][98][80].

Grossman notes that researchers such as Marshall, Keegan, Holmes, and Griffith provide many cases where soldiers, when confronted face-to-face on the battlefield, simply refused to shoot each other and split apart. Looking another person in the face, seeing their eyes and fear, and being in a situation where it is necessary to kill not a generalized enemy but a specific individual, it becomes extremely difficult to deny their humanity^[80].

The Battle of Gettysburg, the bloodiest battle of the American Civil War, is quite a demonstrative example. After the battle, more than 27,000 abandoned muskets were found, 90% of which were loaded, and 12,000 muskets were loaded multiple times. As Canadian historian, journalist, and retired naval officer Gwynne Dyer writes, this could mean that most of the soldiers on both sides were loading their muskets, perhaps even mimicking the act of firing when someone nearby actually did fire in order to hide their internal defection from the killing process but couldn't fire themselves. And many of those who did fire were probably deliberately aiming high^[99][81]. Of course, some might say that the soldiers simply made mistakes when using weapons. But even if, despite all the endless hours of training, you do accidentally double-load a musket, you shoot it anyway, and the first load simply pushes out the second load. And in the rare event of a weapon breaking, you can pick up another one. It is therefore unlikely that a huge number of soldiers could have made the same mistake^[80].

Dyer also cites one interesting fact from the statistics of the U.S. Air Force. Less than 1% of pilots accounted for about 40% of downed enemy aircraft. Most of the pilots didn't shoot down anyone and didn't even try to do it. In addition, when the U.S. Air Force tried to identify commonalities among their World War II aces, it was found that in childhood, they had been involved in a lot of fights. And they were not just bullies who, as a rule, avoid real fights; they were exactly “fighters”^[100][80].

Looking back at how many victims some wars, and especially World War II, had, it is difficult to agree that only 2% of soldiers actually killed their enemies easily. However, this can be explained by distancing. Dyer notes that strong resistance to killing was not observed in artillerymen, bomber crew members, naval personnel, and machine gunners, who, without seeing their target (and whose task was to strike not living humans but non-living objects, even if that meant the attendant loss of life), were able to convince themselves that they didn't kill anyone at all^[100][80].

It should also be noted that the training of soldiers after World War II began to consider the existence of resistance to killing. It was made more effective, and the number of soldiers shooting in combat increased significantly (although this still doesn't tell us anything about how many of them actually aim at the enemy). However, soldiers who do find themselves capable of killing after such training are later unable to cope with what they have done and begin to suffer serious psychological trauma. The cost in the form of post-traumatic stress disorder (PTSD) after killing is, in most cases, unavoidable. It is pertinent to recall the words of military historian Richard Gabriel, who has studied the issue of psychological trauma in soldiers, that the cost of war is usually measured in dollars, lost production, or the number of soldiers killed or wounded, but rarely in terms of individual suffering^{[80][82][101]}.

The traumatic impact of war on the human psyche is also confirmed by the prevalence of suicide among veterans^[82][101]. An illustrative example is that since 2001, about 7,000 soldiers have died in U.S. military operations in Iraq and Afghanistan. At the same time, by 2021, about 30,000 veterans committed suicide. Participation in military operations increases the risk of suicide by 50%^[102].

According to some researchers, including Kevin Dutton, nowadays, psychopaths are extremely common among elite or special forces, where selection is deliberately focused on traits typical of psychopaths. Such individuals are characterized by high psychological stability and cold-bloodedness in military operations. But militarized groups consisting of psychopaths have a “culture of impunity” and are cold-blooded towards civilians. Therefore, they can easily kill peaceful and unarmed people in foreign operations, and authoritarian regimes can use them to effectively suppress internal discontent^[103][104].

In the end, it is worth noting that there is a statement that roughly 80% of males choose to avoid violent conflict. If forced into violent conflict, they just do not fight, although present. The 20% left do not reject violence as a behavioral option. Nevertheless, the main part is probably defensive only, that is, they use violence only if compelled to. Finally, about 1% adopt an offensive elementary strategy. Historical and statistical facts confirm the existence of a ratio noncombatants : defensive combatants : offensive combatants. Roughly, this ratio looks like 80:19:1^[81]. This statement is mentioned by researcher Johan M. G. van der Dennen, who has also done a good job collecting evidence on resistance to killing. However, its primary source is an “unpublished manuscript” that cannot be found. Therefore, we will leave it to your judgment^{[Author's note]}.

▶ See also: Documentary film "The Truth About Killing" (2004)

It is known that the Khmer Rouge exterminated about 1.8 million Cambodians between 1975 and 1979. Khmer Rouge forces consisted of 55 to 80 thousand people in different years. And the population of Cambodia was about 7.3 to 7.9 million people at the beginning of the genocide^{[105][106][107][108][109][110]}. If we take the ratio of Khmer Rouge forces to the Cambodian population aged 15 to 64 (it was 55% of the total population), we will get that less than 2% of people were genocide perpetrators^{[Author's note]}.

Based on the most widely accepted studies, between 500,000 and 800,000 Tutsis were murdered in the Rwandan genocide^[111][112]. And one study suggests that the number of genocidal murderers, consisting of Hutus, had to be 50,000 people. It also states that the genocide was not a spontaneous eruption of tribal hatred, as the Western media portrayed it; this was a coordinated attack by a small core with no more than two dozen leaders and no more than 100,000 of their henchmen in the state machinery (including the military)^[113]. Another study estimates the number of genocide perpetrators (those who committed murder attempts, murder, rape, torture, and other forms of serious violence) from 175,000 to 210,000 people^[114]. The maximum estimate of the number of people who committed at least one act of genocidal violence (including participating in groups that perpetrated genocide and complicity in acts of violence) reaches 234,000. And 90% of the participants were men with a median age of 34 years^[115].

What does this mean? The vast majority of the Hutu people, and even the majority of their active adult (aged 18 to 54) male population, did not take any violent part in the genocide. It can be confidently stated that no more than 17% of the active adult male Hutu population (totaling 1.26 million people) and no more than 9% of the entire active adult Hutu population (totaling 2.58 million people) participated in the genocide. Although these are extremely high and extraordinary figures, there is still no question of a “criminal population” and collective guilt^{[114][115][Author's note]}.

It is worth noting some important considerations. The study estimating the number of murderers in the Rwandan genocide at 50,000 people states that it is not impossible that even 25,000 people could kill hundreds of thousands, if not a million civilians, in 100 days. For such a scenario to become a reality, one murderer needs to commit only one murder every two and a half days^[113]. There is also evidence that in one of the Rwandan military camps, there were 2,000 well-trained soldiers, and of these, just 40 people could kill up to 1,000 Tutsis in 20 minutes^[116].

In order to prove the ability of ordinary men to commit genocides, the example of Reserve Police Battalion 101, which consisted of less than 500 men and killed tens of thousands of Jews, is sometimes mentioned. As noted, the battalion was made up of very ordinary, middle-class men, which may indicate the capability of any group of men to become killers. However, it is important to note that even in this case, up to 20% of the battalion members had serious psychological difficulties in committing killings and eventually refused to do so. In addition, there is a view that questions the claimed “ordinariness” of this group of men and points to the need to find an abnormality that could explain this case^[117][118].

Finally, it is important to note the cases where one individual personally killed thousands of people. For example, the Croatian war criminal Petar Brzica killed up to 1360 Serbs in one night^[119]. And the NKVD officer Vasily Mikhailovich Blokhin executed up to 20,000 people in his entire service^[120]. Such cases only confirm the fact that in the presence of an unlimited opportunity to murder, the murderers will personally commit dozens, hundreds, and possibly thousands of murders. Accordingly, we should always expect that the number of murderers relative to the number of murders will be quite small^{[Author's note]}.

“Universe 25”

“Universe 25” was a famous experiment in which ethologist John Calhoun created a habitat for mice with abundant resources. Initially, the population of mice grew rapidly up to 2200 individuals. However, after that, mice began to refuse to reproduce; their numbers began to decline, and in less than 5 years, the population completely died out. Drawing an analogy to human society, Calhoun concluded that exceeding a certain population density leads to the degradation of the behavior of individuals, the breakdown of social bonds, and, later, the complete extinction^[121].

This experiment was criticized for making many mistakes; for example, the mice's living conditions were actually far from ideal. However, few people are aware that the main mistake was the structure of the habitat, which allowed the 65 largest males to forcefully block all other males from accessing females and food. This caused a chain of events that led to the extinction of the population. A mouse population can live for decades in more well-organized habitats, where it is impossible to establish such a violent dominance hierarchy^[122]. This experiment demonstrates well why, under certain conditions, violence is a threat to the survival of the population and is not an evolutionarily stable strategy^{[Author's note]}.

The Milgram experiment

In 1963, psychologist Stanley Milgram conducted experiments to clarify how much suffering ordinary people are willing to inflict on other, completely innocent people if it is part of their duties. The subject, being in the role of a “teacher,” had to punish the “learner” who was in the other room with an electric shock in cases of incorrect performance of tasks. Of course, being an actor, the learner only pretended to be in pain by knocking on the wall or screaming.

According to published data, one of the series of experiments showed that 26 subjects out of 40 (65%) increased the voltage to the maximum and did not stop delivering electric shocks until the researcher gave the order to end the experiment. And only 5 subjects (12.5%) stopped when the learner showed the first signs of discontent^[123]. Reproduction of the experiment under different conditions and with different people, as stated, showed approximately the same results^[124].

However, after analyzing 656 post-experimental questionnaires, the researchers found that 56% of the participants actually stopped the experiment at one point or another because they believed the person behind the wall was in pain. Another study, looking at 91 post-experimental interviews, found that among 46 participants who continued the experiment after the learner showed dissatisfaction, 33 participants (72%) did so because they simply did not believe that the experiment was real (and the learner actually only pretended to be in pain)^{[125][126][127]}.

This experiment also had serious methodological problems. The researchers put strong pressure on the participants, often going beyond the protocol of the experiment. The professionalism of the actor who played the role of the learner is questionable. And the experiment was based on the deception of the subject, whereas there is reason to believe that unconsciously, most people would recognize real pain or its absence^[128]. These problems also make any attempt to replicate the Milgram experiment questionable^{[Author's note]}.

The Stanford Prison Experiment

Another well-known experiment about violence is the Stanford Prison Experiment. The participants of this experiment were divided into two groups: the guards and the prisoners, who lived in a simulated prison. Soon after the start of the experiment, the guards began to brutally abuse the prisoners, with a third of them showing sadistic tendencies. Two prisoners were even removed from the experiment due to the psychological trauma they received, and the experiment itself was stopped ahead of time for ethical reasons.

For almost 50 years, many believed in the truthfulness of these results. However, the experiment turned out to be completely untenable. The guards were aware of the results that were expected from them and received clear instructions. Potential participants knew in advance what awaited them in the experiment and what roles they would play. And after a while, some of them stated that they only played their role and knew everything wasn't real. One of the excluded participants later admitted that he was only faking psychosis because he did not like the experiment and wanted to leave as soon as possible. Finally, the data researchers published were far from complete; out of the 150 hours of the experiment, only 10% were recorded (6 hours of video and 15 hours of audio)^[129][130].

Other experiments on violence and conclusions about them

It is worth remembering another experiment, the performance of the artist Marina Abramovic called “Rhythm 0,” in which she completely surrendered to the will of the audience, allowing them to use 72 objects and her body freely. As a result, for 6 hours of the performance, she was brutally tortured and even almost shot. It was concluded that all people are cruel, and under suitable conditions, this cruelty will surely break out.

So far, there are no refutations of this experiment. But it can be assumed that it was either staged, like the Stanford prison experiment, with which it is sometimes compared, or the audience was unrepresentative, or cruel people were specially selected as the audience (in many of her performances, Abramovich deliberately put herself in danger and almost died several times)^{[Author's note]}. At least Abramovich's past performances could determine the audience and its expectations^[128]. Note that such assumptions can be put forward for any experiment that allegedly proves the violent nature and cruelty of a human being^{[Author's note]}.

There was also an anthropologist, Santiago Genovés, who believed humans were inherently cruel. To prove this, he placed 10 people of different genders, races, and social statuses with him on a small raft in the ocean. He expected an outbreak of violence to occur in such isolated conditions. However, in fact, no such thing happened, even when Genovés tried to provoke the participants. He was extremely dissatisfied with the outcome of his experiment^[131]. He did not succeed in deceiving the public by adjusting the experiment to a predetermined result, as is usually done by those wanting to prove human cruelty^{[Author's note]}.

Sometimes, it is stated that not a single day in human history has passed without violence and military conflicts. So, it should be a natural phenomenon for humans and human society. However, this opinion is based more on the subjective evaluation of events taking place in the world than on real data, as well as on the excessive visibility of violence against the background of all other events.

There is one illustrative example of how violence can attract significant attention: 69% of Americans believe that domestic violence is a common problem among American football players. This belief is based on media scandals unfolding around players who have actually committed violence. However, statistics show that in the families of American football players, domestic violence occurs almost 2 times less often than on average in American families. At the same time, there is a serious problem of domestic violence in the families of police officers; in them, it occurs up to 4 times more often than on average. But this is information that is often not publicized and investigated^{[132][133][134][135][136][137]}.

Observing violence makes people believe that it is common. However, to give a real assessment, one should rely only on real data and not on arbitrary statements^{[Author's note]}.

Some fictional works can create the false impression that a peaceful person, totally incapable of committing violent attacks, must necessarily be a passive and unmotivated individual. Of course, aggressive stimulus can be important for an individual in many activities. But one should not equate functional aggression with violence.

In Stanislaw Lem's “Return from the Stars,” in order to maintain a peaceful society, people are treated with a procedure called “betrization,” designed to neutralize aggressive impulses in the brain and strengthen the self-preservation instinct. But in reality, people do not necessarily need to have no aggressive impulses or strong fear for their lives to be absolutely peaceful and non-psychopathic. They only need to have strong reflexes and emotions that will impose inhibitory control on aggression (i.e., the violence inhibition mechanism), causing them to have an inner resistance to harming other people.

Another book called “A Clockwork Orange” by Anthony Burgess is based on the author's view that all human beings have an inner drive to commit violence, provoked by “original sin,” and to take away an individual's freedom to choose whether or not to commit violence is unacceptable. Obviously, a work based on a view that normalizes violence is not something we can take seriously. Many people have a strong inner resistance to committing violence, and they certainly do not look like the protagonist of this work after brainwashing that made him unable to defend himself and listen to his favorite music.

As we can see, fictional works' representations of the nature of violence can be extremely misleading. This is always worth mentioning when someone cites them as an argument^{[Author's note]}.

▶ Discuss the topic "Myths and facts about violence"

With plenty of evidence that, in many circumstances, aggressive behavior is restrained, and that people normally have a strong inner resistance to committing violence, we can proceed to an explanation of this phenomenon. To understand the evolutionary reasons for its emergence, we will first look at the theory of intraspecific aggression inhibitions in animals. Then, we will move on to the theory of the violence inhibition mechanism in humans.

In interspecific interactions, the role of aggression is quite obvious, for example, in predation and defense. It is also important in intraspecific relationships, for example, in the division of territory, in reproductive competition, and in the establishment and maintenance of social hierarchy.

Nevertheless, do not make the mistake of looking at aggression in isolation from evolutionary pressures. The two most important of them are the presence of strong innate weapons in conspecifics and their lack of opportunity to avoid each other (due to a limited area of habitat, social behavior, or other reasons). The more pronounced these two factors are, the greater the risks aggressive behavior creates. As a result, its unrestrained forms cease to be an evolutionarily stable strategy of behavior as they begin to interfere with survival, and natural selection directs towards the development of strong restraints, preventing the infliction of serious harm and killing between conspecifics.

The concept of aggression inhibitions was first formulated by the ethologist Konrad Lorenz. According to his theory, they are most developed in animals, which are able to kill an individual of approximately their own size easily (with a single peck or bite). Describing his own observations of wolves, Lorenz showed how aggression inhibitions are activated when one wolf demonstrates to another a gesture of submission or vulnerable parts of its body, such as the neck or belly. As a result, a petrified aggressor cannot continue the attack. Also, observations of ravens showed that they do not peck out each other's eyes, even during fights^[20][21].

To avoid any misunderstandings, it should be noted that wolves are sometimes considered to be animals with a violent dominance hierarchy in which the most aggressive male is in charge. However, in reality, such a hierarchy occurs only in artificial conditions, for example, in zoos, while in the natural environment, aggressive individuals are even expelled from the pack^[138][139].

The ethologist Irenaus Eibl-Eibesfeldt listed many examples of aggression inhibitions from various researchers^[22]. Fiddler crabs, due to their anatomical features, do not open their claws in fights wide enough to injure an opponent^[140][141]. Many species of fish, lizards, and mammals are characterized by the ritualization of fights. A noteworthy example is oryx antelopes, which carefully handle their sharp horns in fights with other oryx but at the same time use them to the full extent in defense against lions^[142]. It is also worth mentioning venomous snakes, many of which squirm, bloat, and push each other during fights but do not bite or even display their weapons^[22][143]. Even very primitive creatures have a similar mechanism. So, jellyfish have a chemical blocker that prevents stinging a conspecific. At the same time, all other living beings are stung automatically^[144].

Aggression is less inhibited in weakly armed species. Compared to ravens, turtledoves with a less sharp beak can even kill a conspecific if it is deprived of the opportunity to escape (for example, placed in a cage). Under natural conditions, conflicts do not threaten the survival of turtledoves in any way; they are unable to kill a conspecific quickly, and it can easily escape. Animals with a solitary lifestyle are also quite aggressive. For example, conflicts pose little threat to the survival of polar bears or jaguars, which, out of the breeding season, rarely cross each other's paths^[20][21].

We should also not forget such a factor of selection against aggressive behavior as inclusive fitness. The basis of evolution is the preservation and spread of genes. And one and the same gene, carriers of which kill each other, has fewer chances for this. Accordingly, developing mechanisms that restrain aggression between individuals sharing enough of the same genes is evolutionarily beneficial. Among other things, inclusive fitness may be one of the evolutionary factors that led to the development of aggression inhibitions in humans, despite the fact that, according to Lorenz, due to weak innate weapons, humans have rather weak aggression inhibitions that do not cover the use of the artificial weapons they have created^{[20][25][145]}. Lorenz was concerned about the consequences of humans becoming the most armed species on the planet. However, due to evolutionary reasons, the vast majority of humans cannot be psychopathic individuals; human society is only able to exist if their number is limited^{[77][146][147]}. The average and healthy individual still has a strong inner resistance to killing, and “it gives us cause to believe that there may just be hope for mankind after all”^[80].

It is necessary to take into account that some unknown and still unstudied factors can weaken aggression inhibitions, as it happens, for example, in lions, which are strongly armed and social species but still kill conspecifics^[22]. Also, Lorenz's theoretical developments are sometimes criticized. For example, there is criticism of his hydraulic model of aggression, which states that living beings have a tendency to accumulate “aggressive energy” if there is no discharging stimulus for a long time, and later, it can be released in the form of aggressive behavior even from insignificant external stimulus provoking it; among other things, this explains spontaneous acts of aggression. However, Lorenz himself recognized the limitations of this model and that it has a number of shortcomings. In addition, there is a study confirming the existence of such a mechanism and even explaining its neurophysiology^{[21][148][149]}. Lorenz may also be accused of labeling aggression as a universal and inevitable phenomenon for humans, but it is worth considering that in his works, he called intraspecific aggression the greatest danger to humanity and expressed optimism about the possibility of eradicating racism and stopping wars. Finally, the criticism of Lorenz's works does not concern his theory of aggression inhibitions^{[21][38][Author's note]}.

Finally, it is necessary to mention the parochial altruism hypothesis. Based on it, intragroup altruism and intergroup hostility have mutually developed during biological evolution and exist side by side^[150][151]. This phenomenon may be argued to contradict the theory of intraspecific aggression inhibitions. However, one study shows that it only explains defensive aggression when there is an imminent threat from competing groups but is not necessarily associated with offensive aggression toward them^[152]. We will address the issue of parochial altruism again in the fifth topic of Chapter Four. For now, it is only important to understand that in the case of humans, intermarriage and trade would have been impossible without inhibition of intergroup killing, and “preliterate” societies would have been locked in eternally hostile and xenophobic isolation, killing any “stranger” on sight^[81].

As we discovered earlier, committing violent attacks on conspecifics is not an evolutionarily stable strategy of behavior for animals that have strong innate weapons and lack the opportunity to avoid members of their own species. The most aggressive individuals, often initiating violent attacks, will also die more often due to the weapons and resistance of their victims. As a result, there will be evolutionary pressure to develop intraspecific aggression inhibitions or so-called violence inhibitor since individuals lacking such a mechanism are less likely to pass their genes on. However, it is worth understanding one important thing: this will not work if the victim of the attack cannot use their weapons in self-defense. This leads us to the assumption that in the presence of an immediate threat to life, the function of the violence inhibitor should be suppressed for a short period of time, sufficient to fight back against the aggressor^{[Author's note]}.

This assumption is consistent with the concept of the threat superiority effect, which we considered at the beginning of our study. According to it, the presence of a threat in the environment and social signals leads to the activation of defense mechanisms and the suppression of other ongoing cognitive processes. In behavior, this effect is often manifested by a fight-or-flight response^[8][9][10].

Also, computer simulations of evolutionary processes have shown that in most cases, neither the belligerent strategy (hawk), which consists in making attacks, nor the timid strategy (dove), which consists in retreating when attacked, are not as evolutionarily stable strategies as the retaliator strategy, which means to behave non-aggressively but in the event of an attack to fight back. Timid individuals cannot compete with aggressive individuals, but aggressive individuals risk getting hurt in fights. Therefore, the mixed retaliator strategy is the most stable^{[153][154][155][26]}.

Neuroscientist James Blair suggested that humans possess aggression inhibitions similar to those observed in many animals in intraspecific relationships and proposed the Violence Inhibition Mechanism (VIM) model. In developing the VIM model, he also aimed to explain the development of empathy as a result of this mechanism functioning and the emergence of psychopathy as a result of its dysfunction^[156][157].

VIM is a cognitive mechanism that is directly activated by the observation of non-verbal distress cues from other individuals, such as a sad facial expression or crying. This causes an aversive reaction, and the stronger the distress cues, the stronger the corresponding reaction: a slight sadness on the face will cause only partial aversion, but screams and sobbing can completely stop the aggressor. Also, VIM is not just a mechanism consisting of an unconditioned reflex (aversive reaction) triggered by an unconditioned stimulus (distress cues). Blair argues that through the process of conditioning (the formation of conditioned reflexes), it becomes a cognitive prerequisite for the development of three aspects of morality: the moral emotions (i.e., sympathy, guilt, remorse, and empathy), the inhibition of violence (regardless of distress cues), and the ability to distinguish between moral and conventional transgressions.

During normal development, regular activation of the VIM on the observation of distress cues leads to the formation of corresponding conditioned reflexes. As a result, the individual becomes able to show an empathic response only by thinking about someone else's distress. Accordingly, during the experiments, film sequences where the victims of violence talked about their experience while not showing any distress cues induced physiological arousal changes in observers^{[158][159][160][157]}.

The inhibition of violence works similarly. As early as childhood (at the age of 4–7 years), normally developing individuals will experience the activation of VIM due to the observation of distress cues as soon as they attempt to commit an act of violence (or even take possessions from another child without their permission)^[161]. Over time, even the very thought of committing violence will begin to lead to this reaction, and the probability that the individual will behave violently will gradually decrease.

The activation of VIM also acts as a mediator in distinguishing between moral and conventional transgressions. The observation of moral transgressions – actions that harm people – and the subsequent victims' distress cues will eventually lead to the development of the conditioned reflex that activates VIM. In turn, social transgressions that do not lead to harm but only consist in violating established social norms will not be associated with distress cues. This is how the individual becomes capable of identifying moral transgressions in various actions. Of course, individuals without VIM can evaluate a moral transgression as a bad act if someone teaches them that it is bad. However, in their evaluation, they will refer to the words of other people without experiencing an aversive reaction to causing harm.

To support the validity of his model, Blair cites the results of many studies. Children with a predisposition to psychopathy and adult psychopaths do show a poor ability to distinguish between moral and social transgressions. The same applies to children with conduct disorders. In addition, and in line with the VIM position, adult psychopaths show reduced comprehension of situations likely to induce guilt. Moreover, children and adults with psychopathy show pronounced impairments in processing sad and fearful facial and vocal expressions^{[157][162][163][164][165][166][167][168][169][170][171][172][173][174]}.

Other studies also support this model. For example, aggressive behavior from callous and unemotional traits, the presence of which in childhood is a prerequisite for psychopathy in adulthood, is associated with a poor ability to recognize fearful facial expressions and fearful body postures^[175]. Children with high scores of сallous-unemotional traits also experience problems in recognizing expressions of sadness, and children with conduct disorder experience problems in recognizing expressions of fear^[176]. People with high scores of primary psychopathy (which is characterized by callousness and lack of empathy) were found to be less able to distinguish genuine distress cues from posed ones. At the same time, this effect did not extend to other emotions, such as happiness, anger, or disgust; it was specific to distress cues^[177]. Schizophrenics with a history of violent crime differ from non-violent schizophrenics in their lower ability to recognize expressions of fear^[178]. Even the most up-to-date research shows that difficulties in recognizing fear and sadness are associated with a greater propensity for proactive (instrumental) aggression in children^[179].

Finally, it is worth noting that psychopathy as a result of VIM dysfunction is a mental disorder by Wakefield's criteria: a condition is a disorder if it leads to harm to oneself or others and is associated with the failure of some internal mechanism to perform a function for which it was biologically designed (i.e., naturally selected)^[180][181].

The VIM model does not provide a complete explanation of the nature of aggression regulation, so Blair later expanded it and developed the Integrated Emotion System (IES) model, which considers the neurophysiology of this process^[162]. However, it still confirms the presence of aggression inhibitions in humans and gives a general idea of how they work^{[Author's note]}.

▶ See also: The problem of indirect violence; The ability to experience empathy and take the perspective of other people in psychopathic individuals; Violence inhibitor dysfunction is a cause of abusive relationships

▶ Discuss the topic "The Theory of the Violence Inhibition Mechanism"

For a more in-depth understanding of how aggressive behavior is regulated, it is necessary to examine this process from a neurophysiological and genetic perspective. Among other things, this is particularly important in identifying a direction for the development of therapeutic approaches aimed at treating violence inhibitor dysfunction in individuals who have psychopathic tendencies and can easily harm others.

One study on moral judgments and behavior suggests that a mechanism similar to Blair's violence inhibitor operates for imagined harm. The neurotransmitter serotonin (5-HT) is responsible for the functioning of this mechanism and plays a parallel role in the inhibition of actual harm (in the case of aggression) and imagined harm (in the case of moral judgments)^[182]. Many other studies also confirm the key role of serotonin in the regulation of aggression in animals and humans^{[183][184][185]}.

The administration of selective serotonin reuptake inhibitors (SSRIs), which increase serotonin levels in the brain and are widely used as antidepressants, has shown interesting results in the issue of aggression^[186]. Fluoxetine administration reduces the risk of aggressive behavior by 4 times in patients with personality disorders^[187]. Also, in one trial, fluoxetine significantly reduced the perpetration of violence by alcoholics toward their spouses or significant others^[188]. In another trial, paroxetine successfully eliminated aggression associated with primary psychopathy (which is characterized by callousness and lack of empathy). And it was found that this did not result from sedative or anxiolytic effects. Researchers believe that primary psychopathy is related to dysfunction of the serotonergic system of the brain^[189]. Sertraline has been tested on violent repeat offenders and found to be effective in correcting their behavior^[190]. Additionally, in several experiments, citalopram improved the ability of participants to recognize facial expressions of fear (as we remember, recognizing distress cues from other people is important in the functioning of the violence inhibitor), increased their generosity, and made them more likely to choose to avoid hurting people in certain types of moral dilemmas (indicating increased harm inhibition)^{[191][192][193][194]}. However, SSRIs can lead to unwanted side effects^[195]. Therefore, we will also review potentially more effective and safer drugs.

Various experiments conducted on mice and rats showed that some agonists of 5-HT_1A and 5-HT_1B receptors (these chemical compounds cause a biological response in receptors or, put simply, activate them) are able to suppress offensive aggression while not affecting defensive behavior or other forms of activity^[196].

Drugs such as TFMPP and eltoprazine significantly reduced aggressiveness in mice and rats in the resident-intruder paradigm while not affecting defensive behavior. This effect was associated with the activation of postsynaptic 5-HT_1B receptors^[197]. In limited human trials, eltoprazine resulted in some reduction of aggression in patients with dementia, psychotic and personality disorders, and mental retardation, with minimal or no side effects^[198][199]. A selective 5-HT_1A agonist called F15599 reduced the manifestation of intense elements of aggression, biting during attacks, and lateral threat postures (demonstrating aggressive intentions) in mice without affecting non-intense elements of aggression and other forms of behavior^[200]. A 5-HT_1B agonist called CP-94253 also reduced the frequency of attack bites and the manifestation of lateral threat postures in mice^[201]. The importance of 5-HT_1B receptors in the inhibition of aggression was also demonstrated in an experiment where the administration of their agonist anpirtoline reduced the manifestation of various forms of aggression in mice, including aggression from social interaction with an opponent and aggression from frustration^[202]. Compared to other 5-HT_1A agonists, a drug called alnespirone showed a highly selective anti-aggressive effect in rats, which did not affect the defensive behavior when the individual encountered an aggressive conspecific and other forms of activity^[203].

It is known that psychedelics that are agonists of 5-HT_1A and 5-HT_2A receptors, such as LSD and psilocybin, can stimulate empathy and prosocial behavior in humans. In one experiment, psilocybin even led to a sustained reduction in patients' predisposition to authoritarian political views (as measured by the Libertarian-Authoritarian Questionnaire), and it is considered to be very useful in treating psychopathy and antisocial behavior. Also, any experience using LSD or psilocybin reduces males' risk of committing intimate partner violence by 2 times. In addition, any experience using psychedelics, as shown in a study of criminal behavior among 480,000 American adults, reduces the risk of committing violent assaults (and psilocybin has a particular protective effect against antisocial criminal behavior)^{[204][205][206][207][208][209]}.

Importantly, experiments on the treatment of hostility and aggression in violent offenders with naratriptan, which is a full agonist of 5-HT_1B/1D receptors and a partial agonist of 5-HT_1A receptors, were once suggested^[210]. And the similar drug called zolmitriptan was successful in selectively reducing aggression in mice and attenuating alcohol-heightened aggression in humans^[211][212]. It has also been suggested that vortioxetine, which is a full agonist of 5-HT_1A receptors and a partial agonist of 5-HT_1B receptors, may be an effective anti-aggressive agent. This is supported, among other things, by preliminary results obtained on a small number of patients^[185][213]. Of course, vortioxetine is also an SSRI, but due to its multimodal mechanism of action, some researchers consider it safer and more effective than other SSRIs^[214][215].

Some natural remedies are also worth mentioning. For example, a herbal extract mixture called Kamishoyosan reduces aggressiveness in mice, and this effect is associated with the activation of 5-HT_1A receptors and improvements in the regulation of the serotonergic system^[216]. The Yokukansan mixture with a similar mechanism of action leads to a selective anti-aggressive effect in mice. It was found that the active ingredient in this mixture is geissoschizine methyl ether from the extract of Uncaria rhynchophylla^[217]. Linalool, which is a component of many essential oils and a 5-HT_1A agonist, also reduces aggressiveness in animals (including through inhalation of its vapors)^{[218][219][220]}. In addition, essential oils may be effective in reducing aggressiveness in people with cognitive impairment^[221].

Finally, supplementation with tryptophan, a precursor to serotonin, may be potentially effective. In experiments on mice and dogs, tryptophan had a selective anti-aggressive effect^[222][223]. And in some human trials, it reduced aggressiveness and hostility and increased trust and generosity^{[224][225][226][227][228]}. Also, tryptophan deficiency in the organism is associated with increased aggressiveness^[229]. Certain probiotics (including various bifidobacterium and lactobacillus) may help increase tryptophan and serotonin levels in the organism. Among other things, they may influence the serotonergic system of the brain through the gut-brain axis^{[230][231][232][233][234][235]}. The possibility of using them for the treatment of violent behavior is already being researched^[236].

▶ See also: The history of the development of anti-aggressive agents for clinical use; Potentially effective treatment of violent behavior in humans

Psychopaths are characterized by an increased propensity for proactive (instrumental) aggression. They also show impairments in empathic response and the regulation of fear-related behavior resulting from amygdala dysfunction. However, other functions of the amygdala, such as the formation of stimulus-reward associations and certain aspects of social cognition, are only mildly or not impaired at all in individuals with psychopathy. The reason for this may be the presence of genetic anomalies, which, instead of leading to severe amygdala dysfunction, have a more selective effect, disrupting the function of specific neurotransmitters^[162].

Based on a framework for understanding conduct disorder developed by James Blair, we get that genetic factors lead to decreased amygdala responsiveness, which in turn reduces emotional empathy, and this is the cause of aggression from callous-unemotional traits, antisocial behavior, and instrumental aggression. Another cause of antisocial behavior and instrumental aggression, as well as under-regulated responses to social provocations and reactive aggression based on frustration, is an impairment in the ability to make decisions, which in turn comes from decreased responsiveness of the striatum and ventromedial prefrontal cortex. Genetic influence also plays a significant role here. Environmental factors such as trauma, exposure to violence, and neglect play a role in increased amygdala responsiveness, resulting in greater sensitivity to threats^[237].

According to a study of 7-year-old children, the presence of both сallous-unemotional traits and antisocial behavior has an extremely high level of heritability (81%). At the same time, the presence of antisocial behavior alone has a moderate level of heritability (30%). Children with callous-unemotional traits are more capable of committing premeditated acts of violence. They have a high risk of developing psychopathy and a propensity for violent crime in adulthood. Their condition is worse than that of other children with antisocial behavior, whose problems are not as severe and long-term^[238]. Also, various studies have shown that the stability of psychopathic traits over different periods of time, even lasting up to 40 years (between the ages of 8–10 and 48), is moderate to very high. This means that psychopathic tendencies emerge at an early age and do not tend to change significantly over time in the same person^{[239][240][241]}.

Different studies demonstrate dozens of genes that affect certain aspects of offensive aggression. However, for its effective regulation, the number of genes and neurotransmitters that play a key role in this process must be limited. And evidence ranging from evolutionary ancientry to pharmacological and clinical data points to the serotonergic (5-HT) system of the brain as the primary regulator of aggressive behavior^[184].

We will begin with the 5-HT_1A and 5-HT_1B receptor genes (in humans, these are the HTR1A and HTR1B genes). Knockout (inactivation) of the 5-HT_1B gene leads to increased aggressiveness in mice. Knockout of the 5-HT_1A gene does not affect aggressiveness, but this is explained by the fact that although this procedure eliminates postsynaptic 5-HT_1A receptors that inhibit aggression through functional activation of the 5-HT system, it also eliminates presynaptic 5-HT_1A receptors that inhibit the 5-HT system itself and increase aggressiveness^{[184][242][243]}. In a study of aggressive and impulsive behavior resulting from alcoholism in Finns and one American Indian tribe, it was found to be associated with HTR1B H861C and HTR1B D6S284 polymorphisms^[244]. In addition, the genotypes of HTR1B rs11568817 polymorphism were found to be different between groups of children with high and low scores of сallous-unemotional traits. And higher scores of these traits were found to be associated with lower blood serotonin levels^[245].

Alterations in the binding potential of 5-HT_1B receptors reflect how severe the symptoms and psychopathic tendencies are in individuals with pathological aggression^[246]. And alterations in the binding potential of 5-HT_1A receptors reflect human aggressiveness itself^{[247][248][249][185]}. Also, changes in the availability of 5-HT_1A receptors in the brain due to alterations in HTR1A gene expression can lead to increased levels of psychopathy^[250]. An assessment of psychopathy scores in male prisoners showed that they were higher in carriers of the T/T genotype of the HTR1B rs13212041 polymorphism in comparison with carriers of the C/C and C/T genotypes. In this case, the T allele results in reduced HTR1B gene expression. Also, childhood maltreatment only further increases psychopathic tendencies in carriers of the T/T genotype^[251].

It is also very important to consider the following three genes: TPH2, MAOA (also known as the “warrior gene”), and SLC6A4. Their respective enzymes are involved in serotonin metabolism in the brain. Mice homozygous for the 1473C allele of the TPH2 gene are more aggressive than mice homozygous for the 1473G allele. In the case of rats and silver foxes, in which low aggressiveness was achieved by selection, increased activity of the TPH enzyme, as well as higher concentrations of serotonin and its metabolite 5-HIAA, were observed^{[184][252][253]}. It should also be noted that the knockout of the TPH2 gene in rats led to aggressive behavior from a decrease in the sensitivity of 5-HT_1A receptors^[254]. Risky haplotypes of the TPH2 gene leading to decreased 5-HT function may also be associated with aggressive behavior in humans^[255].

Knockout of the MAOA gene in mice results in increased aggressiveness and decreased 5-HIAA levels, which also indicates a decrease in the function of the 5-HT system (however, it is important to note that 5-HIAA levels are not a reliable marker of human aggressiveness)^{[256][257][258]}. Males from one Dutch family with a point mutation in exon 8 of the MAOA gene showed increased impulsive aggression^[259][260]. A low-activity allele of the MAOA gene has been linked to a greater risk of participating in gangs among American adolescents^[261]. In addition, it is more frequent in Germans with antisocial alcoholism than without it^[262]. Many other studies also demonstrate that mutations in the MAOA gene are associated with abnormal male aggression^[184][263].

As a study of the role of genotype in violent behavior showed, childhood maltreatment did not make сarriers of the high-activity allele of the MAOA gene more violent than other people. But carriers of the low-activity allele were 4 times more likely to commit rapes, robberies, and assaults in adulthood. Of course, by itself, the low-activity allele of this gene does not make a person more violent but creates such a risk depending on environmental influences^[264][265]. Another study also confirmed the role of the low-activity allele of the MAOA gene in the emergence of physical aggression as a result of traumatic events in childhood^[266]. In addition, one study links increased psychopathic tendencies and “emotional dysfunction” to this allele^[267]. However, it is important to note that various studies have given conflicting results regarding the association of the MAOA gene with psychopathy or have not found it at all, which means that this issue needs further investigation^[268][269].

A study of different variants of the promoter region (5-HTTLPR) of the serotonin transporter gene (SLC6A4, encoding the SERT or 5-HTT protein) showed that homozygosity for the long (L) allele of the 5-HTTLPR polymorphism, which leads to a more rapid clearance of serotonin from synapses, significantly increased the risk of narcissistic and сallous-unemotional traits in young people with low socioeconomic status (based on the income and professional status of their parents). At the same time, the short (S) allele that reduces the reuptake of serotonin was associated with impulsive behavior (regardless of socioeconomic status). It seems that different alleles carry risks for different psychopathic traits and forms of aggression^[270]. However, it is also important to consider that dividing variants of the 5-HTTLPR polymorphism into L and S alleles is too simplistic. In newer studies, the L allele is often divided into L_A and L_G alleles, and it is assumed that psychopathy is associated specifically with the L_A allele. In addition, there are conflicting results, indicating the need for further investigation of the issue^{[271][272][267][269]}.

Finally, it should be noted that the high heritability and significant role of genetic factors in violent and antisocial behavior indicate that gene therapy (e.g., targeting the MAOA gene) is a promising tool for its treatment^[273].

Dopamine receptor antagonists (the drugs that block them), such as chlorpromazine and haloperidol, are widely used in the treatment of aggressive patients, especially those with psychotic disorders. However, their effect is sedative, and they impair defensive behavior in animals. Such side effects limit their usefulness in the treatment of aggressive behavior. The use of barbiturates and benzodiazepines that affect GABA inhibitory neurotransmission faces the same problems. Beta-blockers such as propranolol and nadolol are effective in patients with organic brain syndromes and chronic psychosis, but they can also lead to side effects. Selective serotonin reuptake inhibitors (SSRIs) effectively reduce aggressiveness in patients with personality disorders, but they lead to unwanted side effects. Finally, agonists and antagonists of 5-HT₂ receptors are also able to reduce aggressiveness; however, the former lead to side effects, and the latter are still poorly studied^{[274][275][276][186][195][277]}.

Psychotherapeutic approaches have demonstrated the possibility of significant decreases in psychopathic tendencies and increases in affective (emotional) empathy. However, in some of their forms, particularly those aimed at restraining aggression by improving self-control, there is a risk that the problem will only worsen as the patient learns to commit acts of violence more effectively and thoughtfully. In addition, psychotherapy for such a severe disorder as psychopathy is too time-consuming; the number of therapeutic sessions required can reach dozens, and the entire process can last up to several years. It is worth highlighting the assumption that psychotherapy can be effective in dealing with violent youth and school bullies with high levels of psychopathy, but only at the most intensive level of intervention (at least four sessions per week for a year). Also, psychotherapy alone, without additional administration of medications, may not be effective in the case of alcoholics who are violent toward their spouses or significant others^{[278][279][280][281][188]}.

Considering all this, 5-HT_1A and 5-HT_1B agonists are the most promising drugs in the treatment of aggressive behavior because they have minimal or no side effects. This opinion is also shared by some researchers who support the idea that such anti-aggressive agents (or so-called “serenics”) should be developed^[282]. They claim that “modern research suggests that aggressive behavior should be studied as a separate functional disorder” and “it is hoped that new insights into the neurobiology of aggression will reveal novel avenues for treatment of this destructive and costly behavior”^[283][284]. It has also been suggested that violent and antisocial behavior can be treated with gene therapy targeting genes associated with the functioning of the serotonergic system of the brain (e.g., the MAOA gene)^[273].

Oxytocin is a hormone that plays a crucial role in prosocial behaviors such as trust-building, pair bonding, and mothering^{[285][286][287]}. In intragroup relationships, oxytocin contributes to the establishment of altruism, uniting and coordinating the actions of individual members of the group. However, in the case of intergroup interactions, this is thought only to increase aggressiveness, as a cohesive group is willing to fight outsiders more fiercely. The emergence of wars between different groups of people is often explained by this phenomenon called parochial altruism^{[150][151][152]}.

At first glance, parochial altruism seems to contradict the theory of the violence inhibition mechanism. However, one study shows that this phenomenon only explains defensive aggression when there is an imminent threat from competing groups but is not necessarily associated with offensive aggression toward them^[152]. Also, we will see that there is no contradiction at all if we look at how the two mechanisms interact at the neurophysiological level. The serotonergic system, including 5-HT_1A and 5-HT_1B receptors, is involved in the regulation of oxytocin secretion^[288]. And in one experiment, it was shown that administration of an oxytocin receptor antagonist (a drug that blocks it) to mice only partially prevented the prosocial effect of subsequent administration of a 5-HT_1A agonist but did not reduce its anti-aggressive effect in any way^[289].

It can be concluded that the regulation of aggression and stimulation of prosocial behavior, although significantly overlapping, are still different functions for which different neurophysiological mechanisms are responsible. Therefore, there should not necessarily be a contradiction between the theory of the violence inhibition mechanism and the parochial altruism hypothesis^{[152][Author's note]}.

One study investigated the hypothesis that the male sex hormone testosterone causes pro-aggressive effects through inhibition of serotonergic activity and disproved it. In addition, serotonin has been found to reduce testosterone-induced aggression. This occurs in brain regions such as the medial amygdala, the hypothalamus, the prefrontal cortex, and the lateral septum, which are known to be involved in the regulation of aggression and where a high density of both sex steroid receptors and serotonergic nerve terminals is observed^[290].

This effect caused by the serotonergic system is obviously necessary to restrain aggression so that it does not cease to be an adaptive and functional behavior. And since testosterone does not disrupt its function, it cannot be the cause of uninhibited aggression. Of course, it increases aggressiveness, but only under natural inhibitory control^{[Author's note]}.

There are also claims that testosterone alone is associated with dominant rather than aggressive behavior. Its high levels are common among successful athletes and businessmen. Nevertheless, they are not more aggressive than their counterparts with lower testosterone levels. However, people may experience frustration when their dominant intentions cannot be implemented in practice. In this case, they may become aggressive towards others. But an important prerequisite for such a reaction is reduced serotonin levels in the central nervous system^[291].

Studies show that impulsive aggression can be explained by a dysfunctional interaction between the serotonergic and dopamine systems in the prefrontal cortex of the brain. And it is serotonin hypofunction that predisposes a person to impulsive aggression, while dopamine hyperfunction aggravates this condition^[292][293]. Serotonin is known to inhibit the activity of dopamine, meaning low serotonin levels can lead to an overabundance of it. Serotonin inhibits impulsive behavior, while dopamine promotes it by decreasing emotional regulation^{[294][295][296]}.

Also, one study directly links violent behavior in children and psychopathic tendencies in adults with altered dopamine system activity. And the cause of an excess of dopamine, which leads to increased aggressiveness, is a dysfunction of the serotonergic system that should regulate dopamine production and inhibit aggressive impulses^[297].

Impulse disorders such as pyromania and kleptomania are associated with the release of extra dopamine, and this can cause a person to become addicted to certain criminal activities over time. Similarly, this can work with serial killers, who seek the “ultimate thrill”^[298][299]. It is also suggested that serial killers may need more stimulation in order to get the same pleasure that ordinary people or non-violent criminals experience^[300][301].

▶ Discuss the topic "Neurophysiology and genetics of aggression regulation"

With a direction for developing therapies aimed at treating the dysfunction of the violence inhibition mechanism, we can make concrete proposals and consider how they can be implemented. It will also be important to look at what social changes the widespread practice of such therapies might lead to and why we need it at all.

In order to prevent some misunderstandings, we should note that there is no question of changing the nature of a human being. Here, we consider only the question of treating a specific disorder and enhancing the neurophysiological functions already present in humans.

This Chapter largely demonstrates the author's ideas.

Considering all the available evidence, the most obvious solution for the treatment of violent behavior is the development of a pharmacological drug based on such an agonist of 5-HT_1A and/or 5-HT_1B receptors that will have the most selective effect, activating the violence inhibitor without causing side effects and without affecting other behaviors. This drug can be used in the treatment of patients suffering from increased aggressiveness. It can also be administered to violent offenders as an alternative to imprisonment or other forms of punishment and correction. Perhaps it may even be effective in the treatment of psychopathy.

Another option is to create a gene therapy drug. The best-known example of gene therapy is the treatment of spinal muscular atrophy in children with the drug Zolgensma, which provides a healthy copy of the SMN1 gene^[302]. Also, the possibility of gene therapy for neurological and neuropsychiatric disorders with a genetic origin is being actively studied^[303]. It has even been suggested to use gene therapy targeting the MAOA gene to treat violent and antisocial behavior^[273].

An excellent example of the effectiveness of gene therapy is a trial to treat one serious genetic disorder that leads to a lack of key neurotransmitters (dopamine and serotonin) and causes severe developmental disability and lifelong motor, behavioral, and mental disturbances. During experimental treatment, seven patients aged 4 to 9 years got rid of seizures and began to try to speak and smile, and two of them were even able to walk with assistance, which was previously considered absolutely impossible for such a diagnosis^[304].

Currently, the most promising solution in brain gene therapy is the use of adeno-associated viral vectors as a deliverer of the correct gene variant to the necessary nervous system cells^[305]. And such therapy can even be created in the form of a nasal spray^[306]. An alternative proposal is to use a combination of the technologies CRISPR/Cas9, which allows the replacement of some DNA sequences with others, and iPSC, which involves the creation and application of artificial stem cells^[273].

Of course, gene therapy is still too expensive, but in the future, it may become very affordable, as it was with many other technologies in the past. Now, the main part of the cost of any gene therapy drug is the cost of its development. However, the cost of creating each subsequent dose in mass production should decrease. It is unlikely that, in this case, the cost of the drug will be higher than the cost of modern vector vaccines.

We now need to consider methods for diagnosing the dysfunction of the violence inhibition mechanism. A common approach is screening for psychopathic tendencies by professional psychologists and psychiatrists using an instrument such as Robert Hare's “Psychopathy Checklist” (PCL-R)^[307]. An electrophysiological study of the violence inhibitor has shown that certain amplitudes may provide useful markers for detecting impairments in its function^[11][308]. The creation of portable DNA testing platforms is also possible^[309]. They could be very useful in diagnosing genetic predispositions to violence inhibitor dysfunction. In addition, it is possible to create automated tools for the preliminary detection of psychopathic tendencies when analyzing an individual's behavior. For example, one could use findings from research claiming that, when participating in an interview, individuals with high levels of psychopathy exhibit more stationary head positions, focused directly towards the camera or interviewer (it is worth remembering the concept of “psychopathic gaze” or “psychopathic stare”)^[310][311]. It may also be possible to create an AI solution that assesses an individual's risk of psychopathy by a variety of physiological indicators that are associated with it, such as less tendency to “contagious” yawning, lower levels of respiratory sinus arrhythmia (heart rate changes in response to respiration), reduced heart rate in a calm state, and others^{[312][313][314]}. Current research also shows the possibility of using AI solutions to assess people's personality traits and moral values based on their facial emotional reactions. This approach has an accuracy of up to 86% for each trait and value of a particular individual^[315]. Finally, psychopaths' speech has a number of lexical, syntactic, grammatical, and structural features that reflect their mental state, which can also be used to assess it^[316].

Even children could be tested for violence inhibitor dysfunction from an early age. That small percentage of them with dysfunction, after just a short course of therapy or even a single injection, will undergo healthy socialization and be free of the risk of becoming violent individuals for life. The problem of violence will eventually be solved long before it occurs. Society will come closer to achieving a free and non-violent order, where there is no place for either private violence or violence as a method of governing society.

Another potential solution concerns the defense sector. Technically, it should be possible to create a drug that can be sprayed in the air or even based on a self-replicating viral vector that can be transmitted from individual to individual. At the moment, a similar concept is already being used in attempts to create so-called “contagious” vaccines. Such a vaccine was once successfully applied to the rabbit population in the fight against two viral diseases^[317][318].

Perhaps, based on the current knowledge of the violence inhibition mechanism, it is quite realistic to develop a biological solution that will be the most humane version of a strategic defensive weapon. It can be applied to a hostile army in the event of an attack to enhance the function of the violence inhibitor in its soldiers, resulting in a drastic reduction in its combat effectiveness. In view of the rapid decrease in the cost of biotechnologies, this solution may become available even to small countries that previously could not afford any serious weapons. For societies that have eradicated violence, it could become the primary weapon of deterrence against external threats. Finally, it can be used against terrorist groups stationed in a specific, limited area.

We should understand that the actual application of such a biological solution is extremely risky and should be avoided, limited only to its demonstration to deter potential aggressors from attacking. Though, in general, this is still a much more humane type of weapon than the already existing chemical, biological, or nuclear weapons.

▶ See also: Moral bioenhancement: the only alternative to global totalitarianism and the destruction of humanity; Proactive epigenesis: upbringing and education as a method of epigenetic fixation of non-violence; Potentially effective treatment of violent behavior in humans

The process of eradicating violence through therapeutic correction and enhancing the function of the violence inhibition mechanism in a minority of people with its deficiency and psychopathic tendencies will lead to a number of changes in society. And it is very important to list these changes so that no one doubts the need to eradicate violence.

Obviously, a positive and undeniable consequence of this process is the elimination of violent recidivism, as violent offenders will be forced into therapy. This, together with the treatment of aggressive patients in medical institutions, are the very first areas in which such therapy should be applied. Even within the current social system, without the need to change it drastically, such an idea can be accepted as potentially the fastest, easiest, cheapest, and most effective way to solve relevant problems. This is the first stage that will demonstrate to the general public and popularize anti-violence therapy.

The second stage involves the widespread practice of testing violence inhibitor function in people. Currently, researchers studying the problem of corporate psychopathy suggest that companies could screen potential employees for psychopathic tendencies^[57]. And such a practice could be used in many spheres of human activity. Certainly, individuals with violence inhibitor dysfunction should be offered therapy as an opportunity to avoid any sanctions against them. Also, such therapy could be applied to children who exhibit callous-unemotional traits, which would prevent them from becoming violent and psychopathic individuals.

A controversial point is the potential abuse of such an approach by governments. At first glance, by reducing the level of violence in society, they can selectively increase their violent potential by not applying such therapy to some of their agents. However, in reality, the result will be the opposite. Governments recruit enforcers from society, and the lower the overall level of violence, the lower their ability to do this (let's keep in mind that states are even intentionally selecting psychopaths for special forces, which would be impossible to do if there were no psychopaths in society)^[103].

Ultimately, the following results can be expected:

– Governments will stop using violence to maintain social order. They will have to replace it with other methods, such as reputational and financial sanctions applied to citizens who violate social norms. Thus, a free and non-violent society will be achieved, and the institution of statehood will either undergo radical changes, especially in terms of methods of conducting its activities, or be replaced by something more suitable to a free society;

– Unleashing military conflicts will become simply impossible because a non-violent society will not tolerate this, and no one in it will be ready to participate in military attacks.

Another point of contention concerns the ability of non-violent individuals and societies to defend themselves against violent threats, and how non-violent people can achieve a free society under the oppression of authoritarian regimes. But there is nothing to worry about:

– It must be remembered that defensive aggression or self-defense in the presence of an immediate threat to life is a natural form of behavior, and the violence inhibition mechanism suppresses only offensive aggression^[8][196];

– The therapeutic eradication of violence will not be an instant process, creating a completely pacifist society surrounded by potential aggressors. It will take time, during which it can begin to spread around the world, leading to a gradual, multi-generational eradication of violence worldwide. International practice in eradicating violence will be the third stage of this process;

– A free and non-violent society is able to protect itself from external threats with the help of modern weapons of deterrence, simply making itself an unprofitable victim. One of the options for such a weapon could be a drug for enhancing the function of the violence inhibitor that works on the principle of a “contagious” vaccine^[318]. Of course, the actual application of such a biological solution is extremely risky and should be avoided by using it solely as a deterrent. However, this is still a much more humane type of weapon than the already existing chemical, biological, or nuclear weapons;

– If biotechnology becomes cheaper in the future and easily produced, distributed, and remote tools to affect violent and psychopathic individuals (e.g., drugs sprayed in the air, including genotherapeutic agents) are developed, people could use them against the enforcers of the authoritarian regime when they encounter them. Military research has already proposed the idea of chemical stimulation of protesting people to trust the authorities by spraying in the air drugs that affect the oxytocin system of the brain^[319]. Also, the technology of a “contagious” vaccine has already been tested on animals, and it could be used for malicious purposes as well^[318]. And if some authoritarian regimes actually resort to such practices (and any oppressive measures in general), people could also respond by using biological solutions, for example, by applying to their enforcers agents that enhance the violence inhibitor by affecting the serotonergic system of the brain. That being said, it is also important to note that even biohackers are already able to create genome-editing drugs at home.

Finally, it is worth noting that in the modern high-tech world, there is a risk of using the achievements of scientific and technological progress for violent purposes, including the use of weapons of mass destruction to cause “ultimate harm.” And the matter is not limited to nuclear weapons. The threat of bioterrorism using pathogens created in “basement labs” is already quite real, and it is not known what other threats await us in the future. In turn, eradicating violence and psychopathy will drastically reduce such risk. It may even help to avoid the potential self-destruction of humanity^[320].

It will also prevent another undesirable scenario of global totalitarianism. The problem of causing ultimate harm may seem unsolvable without total surveillance. Moreover, individuals with a desire for power may use modern technology to brainwash the population, making future totalitarianism more resilient than any of its historical examples. But all this is preventable by the practice of “moral bioenhancement,” which can be implemented in the form of mandatory therapy for violent and psychopathic individuals^[320][321].

▶ See also: Moral bioenhancement: the only alternative to global totalitarianism and the destruction of humanity; The philosophy of biological voluntarism

▶ Discuss the topic "The solution to the problem of violence"