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Book Summary: Foragers, Farmers, and Fossil Fuels – How Human Values Evolve

Foragers, Farmers, and Fossil Fuels (2015) argues that the values we hold most dear stem from one fundamental source: energy. While anthropologists have spent centuries attempting to understand differences between cultures, few have attempted to explain those differences. These summaries do just that.

Introduction: Investigate the source of our most fundamental values.

Where do our moral values come from? Is it religion? Philosophy? Our cultural practices and traditions?

Well, yes – religion, philosophy, and culture do play major roles in shaping the expression of a particular society’s values. But in the author’s view, there’s actually a much more fundamental source that determines which moral system we abide by, whether we’re in modern-day Europe or Qing dynasty China. That source is energy.

The following summaries take you on a journey from humanity’s days of hunting and gathering all the way to our present fossil-fuel age. Along the way, you’ll see how energy collection has played a central role in determining whether a society accepted violence or championed equality. And get out your crystal ball – we’ll also be taking a look at how future methods of energy capture could dramatically reshape our values, in as little as 80 years.

Book Summary: Foragers, Farmers, and Fossil Fuels - How Human Values Evolve

In these summaries, you’ll learn

  • what foragers did to upstarts;
  • why farmers ended up with gods and kings; and
  • how Homo sapiens could go extinct.

Our values may have evolved in line with our methods of energy capture.

In 1982, the author and his colleagues were working at an archaeological dig site in rural Greece. One evening, an old Greek husband and wife passed by. The husband was riding a donkey, while the wife was on foot carrying a heavy sack. One of the author’s colleagues asked the husband, “Why isn’t your wife riding the donkey?” The husband replied simply, “She doesn’t have one.”

To modern Western adults, this apparent scene of selfishness might seem unthinkable. But why exactly are most Westerners so averse to gender hierarchies like this one, not to mention other kinds of hierarchies? Are they simply more in tune with the notions of fairness and equality?

The real answer may lie in a more practical phenomenon: the way we capture energy.

The key message here is: Our values may have evolved in line with our methods of energy capture.

Over the years, many people have attempted to understand human values. But not quite so many have attempted to explain our values – that is, why we value what we do.

The author’s theory is that our values evolve – in much the same way that our genes do.

We all know evolution’s basic premise: that organisms with genes most suited to their environment will pass those genes along, perpetuating beneficial traits. Over millions of years, this can result in major changes to the original organism.

Similarly, human values that suit a particular environment will allow a society to flourish, whereas a society with mismatched or outdated values won’t last long. This will lead certain values to dominate and others to die out.

And what force dictates which values stand the test of time? In a word, energy, or more accurately, energy capture. This term defines the process of obtaining or deriving units of food energy – kilocalories – from our environment. Different methods of energy capture work best alongside different values and ways of organizing society.

We can see this in action in our example of the Greek farmer. He probably wasn’t hogging the donkey just because he was a jerk – he may just have been operating according to the hierarchical values of farming societies. Similarly, fossil-fuel users don’t champion gender equality and democracy because we’re saints, but because those values work best in fossil fuel-based societies.

How did this all play out for the earliest human societies? Let’s find out.

Foragers shunned inequality and hierarchy, but accepted violence as a part of life.

In today’s day and age, less than 1 percent of the population still gets its food from hunting and gathering.

It can be hard to imagine a time when all humans were foragers – but for the first 90 percent of human history, that’s exactly what we were. Our energy source was all around us: in the wild fruits, nuts, and animals with which we coexisted.

While foraging groups of the past and present each have vastly different and unique cultures, all of them share a few essential characteristics. This is especially true when it comes to their values.

The key message here is: Foragers shunned inequality and hierarchy, but accepted violence as a part of life.

Foraging groups are generally quite small, consisting of a few dozen to a few hundred people. They’re nomadic, traveling from place to place wherever food is abundant. And they’re particularly resistant to hierarchies – especially when it comes to wealth.

We can measure the specific amount of wealth inequality in a society by looking at its Gini coefficient or Gini score. Gini scores range from 0 to 1, with 0 indicating total wealth equality, while a 1 means that a single person in the group owns absolutely everything.

According to one study that looked at five different groups, foraging societies have an average Gini score of 0.25. That’s significantly lower than both farming and fossil fuel societies.

Why such a low score? Well, foraging involves lots of moving around from place to place. In that environment, it’s a lot easier to have just a few portable possessions than many large items to lug around.

But that’s not all. Food supplies that foragers catch or kill must be shared, so that all group members get the calories they need to survive. In fact, in foraging societies, upstart foragers who decide to start hogging food are mocked, ostracized, or in extreme cases, killed.

It’s true: foragers are equal in most ways, but they’re also indisputably violent. In the twentieth century, one in ten foragers died a violent death.

But why is violence so present for foragers? Well, without centralized governments, eliminating threats is much easier and faster with violence than with diplomacy. And in some foraging societies, violent men have more sexual partners and children than less violent men. For foragers, it seems, evolution favors violence.

With farming came more energy, more children, and the first large-scale societies.

Our early foraging ancestors only had to spend three or four hours a day hunting or searching for food. Sound like paradise? Well, keep in mind that most foragers only lived to the age of 25. And they could only collect about 5,000 kilocalories per day at most.

Around 7000 BC, though, things started changing. Foragers began to do something unusual: they replanted the wheat they found in the wild. Before long, they stopped moving around at all, and instead of hunting for their meat, they got it from large animals they domesticated. They had learned how to generate lots of calories while staying in one place. In other words, farming was born, and with it came many other changes.

The key message here is: With farming came more energy, more children, and the first large-scale societies.

Not all farming societies throughout history were the same. But they did share several important traits.

To start with, most farming societies organized in places where food was naturally plentiful, or – naturally – where the conditions were ideal for farming. Soon, people discovered that massive rivers like the Euphrates, the Tigris, and the Nile could be used for irrigation. Along these rivers, farmers built the first cities, where thousands of people gathered and lived together.

Farming led to a much higher level of energy capture than foraging. By 4000 BC in Mesopotamia and Egypt, irrigation farmers could capture up to 10,000 kilocalories per day. But there was a catch: farming required workers to put in long days of backbreaking labor.

Of course, a single farmer couldn’t possibly handle all the work on his own, which meant that farmers needed to have lots of children who could help out on the farm. But even seven children – the average across all farming societies – weren’t enough. And so they used paid labor – or forced labor.

Evidence shows that farming societies that generated more than 10,000 kilocalories per day all made use of slaves. At the same time, all of them also decided that women should be the ones to stay at home and care for the children while the men worked. The lack of exceptions to this rule is quite remarkable.

Slavery, hard labor, and steep gender hierarchy – farming is sounding like a pretty bad deal so far! Let’s delve deeper into the sorts of values farming societies adopted.

Farming societies were strongly hierarchical and looked more negatively on violence than foragers had.

Picture a day in the life of a typical early farmer. Your land lies somewhere warm and fertile – perhaps Mesopotamia. You have a wife who stays home and cares for your many children. Every day, you wake up and spend the vast majority of your time working, with the occasional social call here and there.

Whether you know it or not, these conditions dictate your most deeply-held values. But what exactly are those values?

The key message here is: Farming societies were strongly hierarchical and looked more negatively on violence than foragers had.

Without exception, every time a farming society rose above an energy capture of 10,000 kilocalories per day, a few so-called “elites” took charge to manage – or control – the populace and their markets. And in almost every case, the person at the top was a god-like ruler whose authority supposedly came from some kind of higher power.

Through religion, farmers rationalized and legitimized hierarchy. To varying degrees, people accepted the idea that a higher power wanted some people to be at the top and others at the bottom. In farming societies, the average Gini score was 0.45. That meant that 10 percent of the population was extracting about 80 percent of the wealth from everyone else.

But the establishment of a ruling class did have a silver lining: it helped quell violence among farmers. An outside entity with ultimate authority could intimidate everyone into acting peacefully instead of violently – at least, most of the time. This was actually good for business, since violence could very easily disrupt the labor process.

And really, ensuring the success of labor was the foundation for everything else in farming societies. After all, farmers could only survive if they produced enough food to live on and enough goods to sell at the market. This encouraged them to work hard to amass material wealth, which they could pass down to their children to ensure their survival, too.

But while material wealth meant survival, it also reinforced gender hierarchies. Possessive male farmers wanted to ensure that they were bestowing their wealth to children who were really theirs. This led to an increased emphasis on virginity, which put women in an even more subservient position.

Farming values held sway across the globe for almost 9,000 years. But everything changed when fossil fuels came into the picture.

Fossil fuel societies flourished by capturing massive amounts of energy.

Northwest Europe, late seventeenth century. Coal miners have just made a remarkable discovery: coal can be burned to generate energy.

But that’s just the beginning. You can use that energy to power engines that pump water out of the mines, allowing you to dig deeper and discover more coal. And, with this surplus of coal, you can power all sorts of previously-unimaginable things. One of these things would turn out to be the steam engine.

The first efficient steam engine came alive in 1776. In no time, it revolutionized modern life. By 1914, the West had economically dominated the globe and were in control of 84 percent of the planet’s landmass. Fossil-fuel societies had taken center stage.

The key message here is: Fossil fuel societies flourished by capturing massive amounts of energy.

After the steam engine came a quick succession of other inventions which increased industrial production. Increased production meant that factories were making greater profits, which allowed them to pay their workers higher wages. These wages enticed farmers to move to cities and get jobs in factories, which made the factories even more productive!

Ultimately, this feedback loop caused markets to explode in size. Mass-produced items were made well, and made to be affordable. After all, there was no point in producing huge quantities of goods if no one could buy them. As a result, everyone’s standard of living reached new heights.

After coal’s big moment, fossil-fuel users continued to improve their methods of energy capture. They discovered new energy sources, like hydrocarbons, and new extraction methods, like deep-sea drilling. In the early days of coal, energy capture was around 38,000 kilocalories per day. By the 1970s, that number had shot up to a whopping 230,000 kilocalories per day.

This massive energy boom required new infrastructure to manage it all. New businesses and financial institutions popped up and then became obsolete at a breakneck pace.

But businesses and wealth weren’t the only things growing thanks to fossil fuels – the world’s population was too. In 1800, just 1 billion people inhabited Earth. In 1900, it was 1.6 billion. And in 2000? 6 billion!

So there’s more of us today than ever before. But that’s not all – we’re also healthier. On average, today’s humans are 10 centimeters taller than our great-grandparents, and we live 30 years longer.

In the next chapter, we’ll find out what all this means for fossil fuel-users’ values.

Fossil fuel societies value equality and prefer peace over violence.

The world today is remarkably homogeneous when it comes to moral values.

A 2007 poll found that 80 percent of people globally are pro-democracy. A 2009 poll of 16 countries found that 86 percent of respondents considered gender equality important. And a cross-continental Gallup poll conducted between 2008 and 2010 found that 69 percent of people are absolute pacifists when it comes to violence.

These results are just a taste of the more equal and peaceful world that fossil fuels have brought us.

The key message here is: Fossil fuel societies value equality and prefer peace over violence.

Since fossil fuels became the dominant source of energy in the eighteenth century, Gini scores have fluctuated greatly. France’s Gini score in 1860 was an astonishingly unequal 0.61, while in the US in 1970, it was a reasonable 0.36.

But despite these ups and downs, the global Gini score today is decidedly lower than it was for our farming ancestors.

Why so? Well, in the fossil fuel age, it’s easy to pay workers high wages and provide benefits. We also don’t need to strongly stratify labor, so it makes sense that everyone should have the opportunity to live well.

As for gender and political hierarchy, they’ve never been as flat as they are today.

There are a number of reasons for this.

For one, as we’ve seen, we’re healthier than ever before – and that applies to our children too. Since they now have a better chance of surviving, there is less pressure for women to have many of them. And while farmers may have needed many extra hands to help with labor, that’s not necessary in the fossil fuel age. So women are able to take up years of paid work, and contribute to the market economy before and after having children.

Another reason for flatter hierarchies is that fossil fuel societies are far more secular than agrarian ones. Without religion, the rule of a god-like king starts looking a lot less legitimate.

This more level playing field allows fossil fuel societies to function well. When citizens are mobile and societies democratic, markets are just more efficient. Similarly, violence seems increasingly unnecessary for solving our problems nowadays.

Of course, not every fossil fuel society has immediately opted for equality and peace over force. Take today’s post-Maoist China. Since the 1980s, China has been growing economically at a much faster rate than other nations. However, this path has also brought with it environmental disaster, intense corruption, and violent protests.

We don’t know exactly how technological advancements will change our values – but we can be sure that they will.

Without a doubt, fossil fuels have shaped how our societies are formed, and which values they hold dear. But we know that technology – both in energy and other areas – is developing at a mind-boggling pace. How might our values adapt to a world that may soon look very different?

One theory that attempts to answer this is called the “Soothing Scenario.” It holds that as countries like China and India continue to develop economic and political power, they’ll start adopting values like freedom and democracy to a greater extent.

Sure sounds soothing. But will it really happen?

The key message here is: We don’t know exactly how technological advancements will change our values – but we can be sure that they will.

There’s already some evidence that supports the Soothing Scenario. Just look at places like Japan, South Korea, and Taiwan, which have all seen great strides toward liberalism since 1945.

Some theorists, however, favor a different depiction of the future. They believe that Asian countries have Westernized mostly because of the West’s dominant global position. If the global power center shifts to the East, they predict, Westerners may find themselves becoming “Chinese-ified.”

This theory also holds some weight. If social development continues to rise at each country’s current rate, Eastern development will overtake Western development in 2103.

Of course, it’s probably unrealistic to assume that we’ll continue to develop globally at our current pace. In fact, development will probably happen much faster!

Conservative estimates suggest that energy capture will leap to almost a million kilocalories per day by 2103. Cities will have populations of 140 million people each. Life expectancy will probably rise to over a hundred years in developed countries. And eventually, we could all be walking around with computer chips embedded in our brains!

With enough kilocalories to feed and power the whole world, all hierarchy could cease to exist. Violence, too, would be pointless in a world where humans are equally empowered by technology. But that’s only if everyone has access to that technology. If the distribution is uneven, a few powerful post-humans could drive the humble Homo sapiens into extinction.

Even if all these guesses are incorrect, we can say with certainty that the humans of 2103 will be very different to the humans of today. And we can also be sure that they will adopt exactly the values that will help them thrive.


The key message in these summaries:

Throughout history, societies have adopted the values that made their particular method of energy capture the most efficient and effective. Foragers had flat hierarchies but frequently used violence to settle disputes. Farmers, on the other hand, had steep political, material and gender-based hierarchies but were less tolerant of violence. And fossil fuel users – meaning us – value equality and see violence as pointless or even morally abhorrent. As for future societies, we may not know what they will look like, but we can be sure that the values they adopt will be the ones that help them flourish.

About the author

Ian Morris is professor of classics and a fellow of the Stanford Archaeology Center at Stanford University.


History, Philosophy, Nature and the Environment, World, History of Civilization and Culture, General Anthropology, Philosophy of Ethics and Morality, Politics, Sociology, Science, Economics

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