In his 2011 book, The Better Angels of Our Nature, Harvard psychologist Steven Pinker documents a persistent decline in violence across the history of humanity. He presents extensive data from numerous fields showing a dramatic reduction in the frequency of wars, murders, and a host of violent practices that were once routine but are no longer used or tolerated. These facts support his claim that the present era is the most peaceable time in history. As I wrote in a previous article, this trend of declining violence is consistent with the long-term trend of human progress predicted by the Wave Principle of social behavior.

Much of Pinker's book is devoted to explaining the causes of this historical decline in violence. He builds a compelling case that the causal variables he identifies were significant contributors to the reduction of violence.

But there are two major limitations of his analysis. First, the factors he cites are not the most fundamental cause of the decline in violence. Socionomic theory provides an underlying explanation of not only the reduction in violence, but also of the causes themselves that Pinker cites.

The second limitation is that Pinker is forced to use a large number of disparate variables to explain periodic increases in violence that run counter to the long-term trend of violence reduction. Socionomic theory, on the other hand, can explain both the long-term trend and shorter-term countertrends using the same explanatory model. Socionomics therefore provides a parsimonious and overarching model that explains the historical trends in violence. It has the added advantage of being able to explain human progress in many other domains as well.

So lets examine the causes of the decline in violence that Pinker presents, and how social mood can explain them. He discusses both external circumstances and psychological characteristics related to changes in violence.

External Circumstances

The reduction of violence from the 13th century to the 20th century was due to what Pinker calls the Civilizing Process. This process had two main triggers, one of which was an economic revolution that involved the rise of commerce.

People discovered mutual benefits to trading with others rather than fighting with them for resources. The positive-sum cooperation of commerce was more attractive and less risky than zero-sum plunder, and so groups eschewed warring in favor of the win-win proposition of trading with each other.

Robert Prechter has written for many years that trade and commerce, which are inherently cooperative ventures, are stimulated by the same positive social mood that causes stock markets to rise. During negative social mood, in contrast, people erect barriers to the flow of commerce, and nations enact tariffs and restrictions to free trade and engage in trade wars. In periods of positive social mood, other parties are seen as partners; during negative social mood, others are viewed as competitors for a shrinking pie.

Positive social mood is the underlying influence that promotes the trust and cooperation needed for buoyant trade and commerce. This can be seen directly during the last three hundred years of stock prices. When social mood became negative, as seen in falling British and U.S.markets, nations put restrictions on trade and engaged in protectionism. When social mood and markets rose, nations expanded free trade.

Pinker also cites the building of roads, infrastructure, and technology as key features in the economic revolution of the Middle Ages. Such mass efforts required energetic initiative and a positive outlook about future prospects.

In 1999, Prechter wrote in The Wave Principle of Human Social Behavior that positive social mood leads people to work hard and embrace effort and constructive achievement. In contrast negative social mood precipitates pessimism and avoidance of effort. An extended period of positive social mood was a necessary precondition for the vigorous economic progress that surfaced in the Middle Ages.

The growth of commerce was aided by the second trigger of Pinker's Civilizing Process in the Middle Ages: the emergence of centralized power in the form of monarchies and nation-states that have a monopoly on the use of force. Among other salutary effects, this decreased the need for individuals to take justice into their own hands. Pinker shows that rates of violent death in non-state societies comprised of tribes and bands are several times higher than in nation-states.

Pinker rightly stresses, therefore, that civilization inhibits violence. But at the root, it is positive social mood that generates civilizing forces; negative social mood generates destructive forces and barbarism. Positive social mood leads people to organize and create laws, processes, and institutions that ennoble humanity; negative social mood leads to behavior that degrades civilization.

Living in an organized society fundamentally requires a certain level of trust and cooperation that leads people to adhere to formal rules, norms, and regulations. As Pinker notes, many criminologists maintain that its not coercive police power that produces the state’s pacifying effect, but rather the trust it commands among the populace. Without this trust the state loses legitimacy. Trust and cooperation are characteristics generated by positive social mood; distrust and opposition are generated by negative social mood.

If state societies tend to inhibit violence, we still need to explain why rates of violence vary over time within states. Socionomic theory allows us to do so.

In a 2009 article in the Socionomist I noted the clear correlation between social mood as reflected in stock market prices and U.S. homicide rates over the past 60 years. One’s chances of being murdered were significantly higher when the stock market was in a significant decline.

Pinker’s book includes a chart of homicide rates from 1560 to 1985 in the town of Kent in England. The overall declining trend is marked by upticks in the rate of homicide in the 18th and 19th centuries, times of falling British stock prices and negative social mood.

Another period that saw a major upsurge in violence was the latter 1960s and 1970s in the U.S. and Europe. Violent crimes such as murder, rape, and assault significantly increased. Pinker attributes this to a sense of generational solidarity brought about by television and the transistor radio, and an "informalizing process" that helped delegitimize establishment authority.

But if generational solidarity was due to television and transistors, surely it would have been maintained or even accelerated by the Internet and all kinds of mobile communication devices starting in the 1990s. But the 1990s actually saw a major decrease in crime rates. As I showed in my Socionomist article, murder rates in the late 1960s and 1970s accompanied a bear market. Negative social mood was the culprit that fomented opposition to authority and establishment power, and that also led to increased homicide rates.

Pinker notes that social scientists are uncertain about why violence declined In the1990s, finding that it was not explained by unemployment rates or economic inequality. The likely answer is positive social mood. The 1990s were marked by one of the strongest bull runs in stock market history and a host of cultural indicators of exuberant mood. Francis Fukuyama observed that as violence declined, so did other indices of social pathology. So a broader force like social mood was at work, not only changes in criminal justice policies such as stiffer sentencing.

A common motive for violence is revenge. Pinker describes apologies as "revenge modulators" because they reduce the likelihood of violent retribution. The 1990s saw an explosion of international apologies by government and religious leaders for past actions, as calculated by political scientist Graham Dodds. Researchers at the Socionomics Institute have documented how international apologies wax and wane in line with social mood as reflected by movements in the stock market. Bull markets, such as in the 1990s, elicit frequent apologies, sometimes even for transgressions in the distant past.

Psychological Characteristics

Pinker describes psychological traits that have a pacifying effect, including self-control and reason, as well as traits that impel us to violence, such as dominance and revenge. The former are the "better angels" of our nature and the latter are our "inner demons."

The brain contains competing systems for impulse and self-control. Circuitry in the frontal lobes implements self-control and inhibits violent behavior. A large body of research by psychologist Roy Baumeister shows that self-control is a variable resource that, like a muscle, can become fatigued and depleted under certain conditions. It can also be strengthened through practice.

Self-control can also be identified in social indices of nations. Sociologist Geert Hofstede found lower homicide rates in countries that emphasize restraint over indulgence and that also have a longer-term orientation.

Effortful control is a term used synonymously by researchers for self-control. Fighting a strong urge requires strenuous effort. The terms willpower and strength of will allude to the intensity of effort involved. In The Wave Principle of Human Behavior, Bob Prechter wrote that positive social mood stimulates both physical and mental effort, while negative social mood is associated with avoidance of effort. So positive social mood stimulates the effortful control that inhibits violence, whereas negative social mood reduces that restraining influence.

Prechter also wrote that people tend to emphasize reason and rationality during periods of positive social mood; negative social mood is associated with superstition and fuzzy thinking. Pinker lists the faculty of reason as one of the better angels and presents data showing humanity has in fact become smarter during its history. A smarter and more rational world is less violent. He also shows how models of morality have moved to a more rational basis. Thus, positive social mood leads to greater rationality and cooperation, while negative mood leads to irrationality and violence.

Pinker lists dominance as one of the inner demons that propels violence. As Hobbes wrote in 1651 in Leviathan, in competition, men "use violence to make themselves masters of other men's persons, wives, children, and cattle." And many wars, Pinker writes, have been "fought over nebulous claims to national preeminence" (p. 515).

Prechter wrote that negative social mood is associated with desiring power over people, whereas positive social mood brings a laissez faire attitude. Mass mood creates the social environment that either fosters or restrains the desire to dominate others. Prechter also wrote that negative social mood leads to political repression whereas positive sentiment induces political freedom. Pinker states that democracy is an inhibitor of violence. Thus, negative social mood leads to the urges to dominate and control that can precipitate violence.

Pinker includes revenge in the list of violent inner demons. He notes it is the motive for 10 to 20 percent of all homicides. It's a recurring theme in film and literature and it's ubiquity is illustrated by sayings such as "Revenge is sweet," and "Don't get mad, get even."

As Pinker describes, the neurobiology of revenge begins with the Rage Circuit in the midbrain-hypothalamus-amygdala pathway, which prompts an animal that has been hurt or frustrated to lash out at the nearest likely perpetrator. Prechter in 1999 listed anger and malevolence as characteristics of negative social mood, whereas forbearance and benevolence characterize positive mass mood.

Fear is another characteristic of negative social mood, and fear can prompt preemptive violence in order to prevent being attacked. Pinker quotes Hobbes statement that competition can lead to fear. If you suspect your neighbor intends to remove you from competition by killing you, your anxiety can incline you to a preemptive strike. In other words, fear can lead to doing unto others before they do unto you.

In the major bear market and negative mood environment of 2002, the Bush administration developed a doctrine of preemptive military attacks. It asserted that the U.S. was justified in invading other sovereign nations whenever it felt its security was threatened. It raised preemptive military action to the level of explicit national policy, in disregard of international law. Such a policy would have been much less likely during a time of less fearful, more positive social mood.

Positive social mood fosters self-control and reason, Pinker's "better angels" that inhibit violence. Negative social mood stimulates Pinker's inner demons of dominance, anger, and fear that can increase violence. Negative social mood also contributes to ideological violence and sadism, two other inner demons he mentions.

Social mood is the underlying dynamic that fosters both the external circumstances and inner psychological characteristics that explain the long-term reduction in humanity's violence. Social mood also explains the shorter-term waxing and waning of violence. And it does so with a single unifying construct that is powerful and elegant.

A Theory of Everything (social)