To understand our current deteriorating sociopolitical and economic environment it’s instructive to view current events through the lens of a broad social-science perspective. In this article I wish to apply our scientific knowledge to explain why the economic and financial boom–bust cycles tend to end in periods of social and economic depression.


Recently, President Trump has started trade wars, delivering on his anti-free trade campaign promises to “cure” the United States’ growing structural problems of huge trade deficits by attacking global trade of goods. Pro free-market thinkers have criticized these protectionist measures as counter productive, concerned they will cause retaliatory responses from other trading partners and snowball into the collapse of global trade. Many economic commentators have raised the alarm, reminding us of similar episodes from past history, such as the Smoot–Hawley Tariff Act imposed by Republican President Herbert Hoover in June 1930 that plunged the world into the Great Depression and World War II. Such an aggressive stance, promoting social group conflict and strife, will prove to be an unwarranted step that will backfire.

This raises the question of why we keep repeating the mistakes of history in the face of rational economic analysis that suggests we are taking the wrong path, leading to our own destruction. If we suspect that irrational motivations can be at the root of human social behavior, then we have to increase our scope of study from merely economics to other disciplines in the social sciences. Evolutionary psychology, for example, can explain how the basic instincts and evolved psychological adaptations drive our complex social systems.

The term hormones means impetus. Hormones motivate biological organisms to act in ways that further themselves.  Our hormones function to adapt us in response to changing environmental conditions. As I describe in my new book, Sex Wars: How Hormones Drive Gender, Race, and Culture Conflicts (2018), testosterone is a sex hormone that drives the sexual organization of our society: It regulates our reproductive life cycles and how we form social dominance hierarchies as we seek territorial goals and resources.

As I further depict in my books, when the levels of growth hormones—such as testosterone, serotonin, and dopamine—rise, people feel happy, secure, and confident. They seek mutual cooperation that promotes economic growth through the global economic division of labor. In 1776 the Founding Fathers of the United States created the Declaration of Independence, promoting the values of life, liberty, and the pursuit of happiness, thereby securing individual rights under the rule of law. That same year, Adam Smith published The Wealth of Nations, promoting global free trade to enhance comparative advantage and increase economic productivity. This was the peak of the European Enlightenment that would lead to the scientific revolution, the rise of capitalism and industry, and a giant increase in wealth and health across the world throughout the next few centuries.

However, in the early twentieth century, testosterone levels declined. As a result, socialism and protectionism began to rise in the West. The subsequent loss of individualism gave rise to collectivist ideologies, such as fascism and Nazism in Germany and communism in Russia. These movements are based on group conflict and identity politics, and they lead to economic collapse and war. Fortunately, rising testosterone levels in the 1940s and 50s brought about a positive trend in social mood that allowed for the triumph of Western liberty and capitalism in the second part of the century.

Solar activity (light) raises testosterone levels and brings a culture of masculine independence and a spirit of liberty and enlightenment—a term itself derived from “light.” There is much research that reinforces this assertion, showing that light therapy has positive effects on mental and physical health, like depression or fertility.  A 2016 study investigated the effects of light therapy on men with low libido, for example, finding that just 30 minutes of morning light therapy increased their testosterone levels by 50% and more than tripled their self-reported sexual satisfaction. As lead researcher Dr. Andrea Fagiolini explains:

The increased levels of testosterone explain the greater reported sexual satisfaction. In the Northern hemisphere, the body’s testosterone production naturally declines from November through April and then rises steadily through the spring and summer, with a peak in October.

You see the effect of this in reproductive rates, with the month of June showing the highest rate of conception. The use of the light box really mimics what nature does. We believe that there may be several explanations to explain the underlying mechanism. For instance, light therapy inhibits the pineal gland in the center of the brain, and this may allow the production of more testosterone, and there are probably other hormonal effects. (

As can be seen in the following chart, since the year 2000, solar activity—as measured by sunspots—is in rapid decline, affecting hormone productivity and social mood globally. Hence, we are again experiencing a period of deteriorating social mood, leading to manic–depressive financial boom–bust cycles, repeating the great recessions of 2000 and 2008, and again beginning in 2018, which may lead to another Great Depression.


This raises a fundamental philosophical and scientific questions: Is mankind to be forever trapped in recurring cyclical patterns of history? Are we to fall in submission to this fatalistic worldview? Or can we rise up to transcend our inherited biological drives?


Roy Barzilai is the author of three books: The Objective Bible (2014), The Testosterone Hypothesis (2015), and his new book, Sex Wars (2018).