Chimp Empire and the economics of chimpanzees

Watching Netflix's new docuseries Chimp Empire is a trip. It feels like being dropped in the middle of the Ugandan forest and suddenly becoming roommates with chimpanzees. It's incredibly immersive. You get to know the chimps as individuals, each with their own personalities and goals. And you get a glimpse of the inner workings of chimp society, complete with its fluid hierarchies and deadly power struggles.

Chimp Empire was filmed over a year in Uganda's Kibale National Park. The filmmakers embedded themselves with the Ngogo chimpanzees, the largest known chimpanzee society. While these chimps once lived in relative peace and harmony, they now have split into two warring clans, which scientists refer to as the Central and Western factions.

For us at Planet Money, what's particularly fascinating about this conflict is that economics seems to be at the center of it. The Central and Western chimp clans are competing for the ownership of a scarce resource: fruit trees, which are their primary source of sustenance. At the beginning of the series, the Central chimps have control over some of the most coveted fruit trees. They even patrol their borders to ensure that the Western Chimps don't encroach on them. But — without giving away too much — the Western Chimps do exactly that, and the territorial conflict turns violent.

The apes in Chimp Empire also display other behaviors that are interesting from an economic perspective. Alpha males use the spoils from their group's hunts strategically, giving meat to allies while excluding those who pose a threat to their dominance. The chimps also engage in a kind of grooming barter system. Ticks and other parasites are a serious problem in the jungle, and the chimps spend hours grooming each other to ensure that they don't get sick. It's literally you scratch my back, and I'll scratch yours. However, in the docuseries, there are stories of low-ranking chimps grooming higher-ranking chimps but not getting groomed in exchange. In this way, this grooming barter system communicates power, kinship, and rank.

Chimpanzees, as a species, are our closest relatives in the natural world. Scientists have compared their DNA to ours, and they find that more than 98 percent of our genetic code is identical. Research suggests that humans and chimps both share a common ancestor species, and somewhere between six and nine million years ago, we diverged and started evolving into the distinct creatures we are today.

Given our primal connection to chimpanzees, social scientists have long been interested in our behavioral similarities and differences — including when it comes to our economic behavior. By understanding how this more primitive species behaves, the thinking goes, maybe we can gain a better understanding of how humans behaved in the ancient past, and how we've evolved and changed with civilization.

Chimpo Economicus

In the classic model of neoclassical economics, human beings are portrayed as selfish creatures who always do the best that they can to maximize their own wealth and happiness. The model assumes that people are rational, meaning that they will logically pursue their goals and not get systematically tripped up by their quirks, shortcomings, or emotions. Economists call this stylized version of humans homo economicus.

Over the last few decades, the field of behavioral economics has shone a bright spotlight on the fact that human beings often don't behave like homo economicus. They engage in all sorts of behaviors that can result in them failing to maximize their own wealth or happiness. Sometimes they do so because of irrationality, or errors in their thinking. Other times they do so because they choose to do so. For example, humans, perhaps because of innate empathy or socialization, tend to be more generous and altruistic than the crude, simplified economic model of the past suggests we are. And, this, evolutionarily speaking, makes a lot of sense. We are, after all, a social species: the more we cooperate, the more we thrive.

With this model of behavior in mind, social scientists have long been interested in researching whether chimps are more or less selfish than humans. For decades, researchers conducted lab experiments with chimps that suggested they were, indeed, almost completely selfish. They found in laboratory experiments that chimps tended to hoard food and were unwilling to hand over snacks to fellow apes, even when it didn't really cost them anything. This made it seem like maybe kindness and concern for others was more of a human trait, and that chimps were closer to the crude model of selfish homo economicus than we are.

However, more recent experiments have found that, in fact, chimps are actually more generous than once thought, and even that they are more social and evolved than selfish homo economicus. In one experiment, researchers Michael Tomasello and Felix Warneken put two chimps in two different rooms. Both primates had a clear view of mouth-watering fruit in a third room. The scientists gave one chimp the capability to open the door for the other chimp to go and get the fruit, even though the chimp with control over the door wouldn't get to feast. The researchers found that the chimp opened the door for the other chimp around 80% of the time. Pretty generous!

Other studies have found similar behaviors. Chimps warn their compatriots about imminent dangers. They give tools to their compatriots when they request them. So while humans may be more generous than apes, researchers find that concern for others is not a uniquely human trait.

The Endowment Effect

Chimpanzees also display some of the same quirks that humans do. Behavioral economists have long found that humans, quite irrationally, tend to value an object more after they have gained possession of it. For example, we might think a coffee mug is worth only $5 when we buy it at the store. Then, after we buy it, we value it more. Someone could offer us like $8 or $9 for it. But, we're like, "No way! This is my precious mug!" From a purely rational economic perspective, this behavior doesn't make sense.

Richard Thaler, a founder of behavioral economics, called this tendency to value things in our possession more "the endowment effect." He connected it to a broader human quirk, which is called loss aversion. The basic idea is that we experience more pain from losing something than pleasure from gaining that exact same thing. We see this behavior everywhere, whether it's our romantic relationships or our consumer decisions. You may sort of like getting something, but you'll really hate losing it!

What's interesting is that a group of researchers has found that chimpanzees exhibit the exact same behavioral quirk, particularly when it comes to food. "These findings suggest that many seeming deviations from rational choice predictions may be common to humans and chimpanzees and that the evaluation of these through a lens of evolutionary relevance may yield further insights in humans and other species," the researchers conclude.

So maybe, apart from human cognitive ability, language, advanced technology, and civilization, chimps aren't so different from us after all. At the very least, we're both much more interesting, social, and quirky than the creatures portrayed in old-school economic textbooks. [Copyright 2023 NPR]