INDIVIDUALS, GROUPS AND EVOLUTION

CCBE – Part 12: WEIRDness made us forget the importance of groups

How Western cultural biases emphasise competition and individuals over groups and cooperation

Today, we’ll talk about cooperation and competition between and within species. This will exclude our closest living relatives, the great apes, because we’ll discuss them next time.

To see how biology and evolution work across multiple scales in parallel, we’ll look at individuals and groups. This leads to an important arm wrestle in evolutionary theory that defined much of 20th century biology, as the role of groups was generally dismissed.

Instead, evolutionary biologists focused on the individual, and we’ll unpack the historical context that led to this view. We’ll also describe how the importance of groups has been revived in the last 15 years. Let’s get to it!

Between species

Competition between species is well known. With a limited supply of territory and resources, there are many reasons for conflict in every ecosystem. In this way, competition is often viewed as the defining feature of life in a harsh Darwinian world.

But cooperation between species is also common. Contrary to the modern Western emphasis on competition in nature, this shows that nature is more than just ‘red in tooth and claw’, as the old expression goes.

For instance, in his book Are We Smart Enough to Know How Smart Animals Are?, evolutionary biologist, Frans de Waal, describes how large fish and eels team up to hunt smaller fish.

Humans appear to be particularly expert at inter-species cooperation. For example, we cooperate with dolphins to catch fish in places like Brazil. Research suggests that people in southeastern Australia may have even worked with orcas to hunt whales.

We also cooperate with birds. For instance, the Tikiliko bird in Tanzania cooperates with Hadza hunter-gatherers. The birds help to locate beehives, wait for the Hadza to take their fill, and then eat the leftovers. And of course, we’ve domesticated many animals and plants.

Within species

Competition within species is equally familiar. And with competition for mates added to the mix of scarce territory and resources, within-species competition can be ferocious.

But here again, there are many examples of cooperation as well. Cleaner fish are a great case of both. They eat stuff trapped in and on other fish, thus providing a cleaning service. But this cooperation hides darker motives, as cleaner fish prefer to take bites out of their clients.

To maximise their food, cleaner fish try to strike the right balance between cleaning and eating their customers. If they only clean, they might not get enough energy and nutrients. But if they bite too many of their clients, ruining their reputation as a cleaner, this can also lead to malnutrition.

To maintain the right balance, cleaner fish police each other, becoming aggressive towards cleaner fish who are all bite and no clean. There’s also a between-species element, as there are fake cleaner fish! These frauds exploit their resemblance to steal a cheap meal while trading on the cleaner fish name. Who knew being a cleaner fish could be so complicated?

Blood-sucking bats are another cool example. Our vampiric mammalian cousins live in colonies, share blood, and feed their young communally. This is because they tend to starve fairly quickly, so cooperation benefits everyone.

Like the cleaner fish, they police each other, and if a bat doesn’t share, the community reacts by not feeding the stingy bat’s young. Vampire bats even keep personal tabs and repay favours, with cooperation most common among individuals that interact regularly.

Cooperation and competition are also pillars of chicken society. For example, studies show that more aggressive hens lay more eggs than less aggressive hens when they’re mixed together.

But selectively group aggressive hens together, and they now lay fewer eggs because of the constant in-fighting. Repeat this for a few generations, and the hens become violently homicidal. Evolutionary biologist David Sloan Wilson, who conducted the research, described them as psychopathic chickens.

Meanwhile, chicken coops with hens who live together peacefully end up laying more eggs. This shows how the dynamic of the group can be a powerful factor. And while details vary, this principle plays out in every social species.

A champion team versus a team of champions

What’s the takeaway from this? Aggressive individuals outcompete more cooperative individuals, but internally-cooperative groups outcompete internally-competitive groups.

In this way, what’s good for the individual can be bad for the group. As we saw with the psychopathic chickens, there’s also a feedback loop, as what’s bad for the group is often bad for the individual as well, at least on the long run.

This is only a handful of examples, and there are many others. Since that’s the case, why have the important roles of cooperation and groups in evolution been ignored (and often denied) for so long? It’s because the West is WEIRD.

A bias for individuals in the WEIRD world

For a long time, Western biologists viewed groups as no more than collections of individuals. This is because WEIRD psychology has evolved a bias for focusing on the individual.

As a modern example, this view was demonstrated by British Prime Minister, Margaret Thatcher, who said famously that “there is no such thing as society. There are individual men and women, and there are families.” This focus on the individual is known as methodological individualism.

If you’d like to learn more, check out my article on the cultural evolution of WEIRDness.

Multilevel selection theory

Despite the direction of historical and cultural trends in the West, a minority of rebels swam against the current. They argued for the importance of groups in their own right, not merely as groups of individuals. No one carried this banner higher than evolutionary biologist, David Sloan Wilson.

For decades, researchers like David were dismissed out of hand when they argued that groups played a role in evolution. But to their credit, they actually began to win the debate about 15 years ago. There are always some die-hard researchers who refuse to change their mind. But the facts have become too clear to deny, and most evolutionary biologists don’t even try.

It’s now widely accepted that individuals and groups both play important roles in evolution. This is more formally known as multilevel selection theory.

Recognising the role of groups in evolution may seem minor. But given the WEIRDness of the West, just acknowledging that there’s more than the individual is fairly significant. The same goes for the role of cooperation, which is often obscured by the standard bearers for competition.

Key points

Individuals and groups are both important elements in the evolutionary mix. This has been difficult for the WEIRD world to accept, given its cultural preference for individuals.

But due to the weight of evidence, the role of groups in evolution can no longer be denied. If you’d like to learn more about this topic, I strongly recommend the book This View of Life: Completing the Darwinian Revolution by David Sloan Wilson.

Our overemphasis on competition, and neglect of cooperation, have also been exposed. Contrary to nature red in tooth and claw, cooperation is very common. While individuals and groups compete, they also cooperate.

The general rule is this. Competitive individuals outcompete cooperative individuals. But cooperative groups outcompete competitive groups.

Ironically, this is often because cooperation gives a competitive advantage. Think about lionesses hunting in numbers to improve their odds, or groups of lion brothers teaming up to dominate a territory. This sort of cooperation is still zero-sum, as one party must lose for the other to gain.

But as we saw with chicken society, within-group cooperation can benefit the individual and the group without being driven by intergroup competition. The teamwork between eukaryotes and our mitochondria, and the symbiosis between oxygen-consuming animals and CO2-consuming plants, make a similar point. Such positive-sum dynamics have many merits, as we’ll discuss when we wrap up the series.

Next time

This has important implications for how we understand ourselves and our closest living relatives, the great apes. Particularly in the West, where WEIRDness is king, the importance of groups challenges many of the cultural assumptions baked into our individualistic psychology.

But despite this, most WEIRDos are already familiar with some of the big takeaways. Most importantly, we and the other great apes are social species. Group membership is essential to life, and loneliness is literally deadly.

However, this doesn’t mean group life is easy, as the interests of individuals and groups are often tenuously aligned, at best. This dynamic is loaded with cooperation and competition, and has much to teach us about ourselves. We’ll unpack this next time when we discuss the great apes.

We’ll focus on chimps and bonobos, our closest living relatives. As we’ll see, they have very different lifestyles, temperaments, and social structures. Strangely, though, when we look in the mirror, it’s easy to see both chimp and bonobo characteristics staring back at us. Until then!