What’s it about?

Survival of the Friendliest (2020) presents a scientific look at the origins of human sociability. This history of humanity demonstrates how evolutionary pressure made us the friendly, community-oriented species we are today.

About the author

Brian Hare is a professor of evolutionary anthropology at Duke University’s Center for Cognitive Neuroscience and co-author of The Genius of Dogs, a New York Times bestseller.

Vanessa Woods is a research scientist at the Duke Center for Cognitive Neuroscience, the co-author of The Genius of Dogs, and the author of her own title Bonobo Handshake.


Humans have developed unique cognitive abilities to aid cooperation:

Let’s begin with a lighthearted game: Take two cups and place a treat or a brightly colored toy in one of them. Then, give a baby the pair of mugs. Will they be successful in locating the prize?

Yes, it is true! That is if you hint at it. Simply point to the appropriate cup and see what happens. Most infants can understand this gesture to communicate something essential by the age of nine months. They’ll investigate the item indicated by your finger.

It may not appear to be remarkable, but it is. It demonstrates that even as children, humans can perceive that others have knowledge and purposes that are different from their own. This is known as the theory of mind, and it is one of humanity’s most significant accomplishments.

At first glance, the theory of mind may appear to be a fundamental cognitive ability. After all, it seems self-evident that others have their thoughts, feelings, and experiences that may differ from ours. However, this is a sophisticated concept that even our nearest evolutionary ancestors do not have.

Try playing a chimp in the same two-cup game. You’ll rapidly become irritated. Even if the chimp is aware that food is under one of the cups, your pointing will be misinterpreted as practical action. They’ll just make an educated estimate. A monkey may pick up on a gesture after dozens of repetitions but modify the motion even slightly, and it’s back to square one.

Surprisingly, dogs fare slightly better. When you point to the correct cup, they are more likely to study that thing rather than the other. While it’s uncertain if they understand the meaning of our gestures, they do follow them instinctively.

Why is there a distinction? We’ve tamed dogs, after all. We’ve nourished and raised dogs that obey our directions throughout history. This gives those who work well with human communication an evolutionary advantage. Because chimps haven’t been subjected to the same evolutionary pressures as humans, they haven’t developed the cognitive ability to comprehend our motions.

As a result, the ability to imagine and converse with other minds is an evolved talent. But that begs the question: why do humans have the most refined understanding of the theory of mind of all the animal species on the planet? Evolution, as we’ll see in the following few paragraphs, may be able to supply some answers.


Friendliness is a genetic feature linked to improved communication skills:

Dmitry Belyaev, a geneticist, relocated from Moscow to the far-flung city of Novosibirsk in Siberia in 1959. He began a long-term experiment here, away from the suspicious gaze of Stalin’s administration. You can see the fruits of his labor now. You can pick them up and pet them.

Belyaev’s experiment was an attempt to domesticate foxes, which he was successful at. The scientist started with two groups of foxes in the wild. One group was kept alone, while the others were only allowed to reproduce if they demonstrated a strong affection for humans.

The two groups diverged significantly over time. The friendly group gained various new physical and behavioral features, whereas the control group remained the same.

For over 50 years, Belyaev has been conducting his domestication experiment. Lyudmila Trust, one of his protégés, keeps it going today. The result is breathtaking. The foxes that have been bred for friendliness differ significantly from their wild counterparts.

For starters, they don’t appear to be the same. Floppy ears and a shorter snout distinguish the friendly foxes. They have softer fur that comes in a range of hues and patterns. Their teeth are also less sharp. They have many of the same characteristics as other domesticated animals like dogs and pigs. None of these characteristics, on the other hand, were deliberately chosen. They’re just byproducts of the main selection criterion, friendliness.

The most critical side effect of choosing friendliness isn’t a physical characteristic. It’s a mental skill. The friendly foxes have a much better ability to converse with humans than the other foxes. When wild foxes are given the two-cup test, they fail around half of the time. The friendly foxes, on the other hand, can recognize human signals and select the appropriate cup. Surprisingly, they retain this ability even if controlled foxes rear them.

This ability gap is astounding because it demonstrates that friendliness and communication skills are related to the same genetic process. When evolutionary pressure favors one, it also benefits the other. Other domesticated species, such as ferrets and Bengalese finches, show a similar pattern.

We’ll see if this process can happen without human involvement in the following paragraphs. Is it possible for a species to self-domesticate?


The sociable bonobo exhibits all of the hallmarks of self-domestication:

Do you want to live among the chimps? Sure, it may appear enticing at first. Perhaps chimp life consists of nothing more than lying in the jungle and monkeying around. Regrettably, the reality isn’t quite so lovely.

Chimpanzee society can be rather cruel at times. Male chimps monitor their region regularly and will attack any intruders. Worse, they’ll physically assault potential mates during mating season. The situation isn’t much better for female chimps. They frequently fight and, in some cases, murder the children of their competitors.

No, the bonobo is a better choice if you’re searching for a more serene primate life. While this type of ape is closely related to chimps, it is far more pleasant and cooperative.

What is life like for bonobos if chimp society is violent and competitive? For starters, it’s a lot more relaxed. Most importantly, there is no competitive rivalry among friends. Instead of males battling over a few select females, females choose who they have relationships with and choose practically everyone. Sex actions are a systematic way for bonobos to socialize.

Bonobos don’t get into fights over food, and they don’t get into conflicts over partners. They, on the other hand, prefer to share. In one demonstration, scientists isolated a group of bonobos in a room with fresh fruit and a little door that kept another bonobo out. Even if they’d never met before, the first ape always chose to let the second in. When given the same option, chimps simply devour everything.

Unsurprisingly, these nicer apes share some of the morphological characteristics seen in domesticated animals. Their faces and jaws are smaller and less prominent, and their teeth are tinier and less ferocious. Even when completely adult, they exhibit more variable coloration, with pinkish lips and tufts of light-colored hair.

Bonobos, like domesticated foxes, exhibit indicators of improved communication and cooperative abilities. When given a challenge that demands collaboration, such as a puzzle that requires two apes to pull ropes at the same time to earn a treat, bonobos are fast to cooperate. Their chimp counterparts, on the other hand, are rarely able to do so.

These different physical characteristics and more egalitarian behaviors appear to imply that bonobos have gone through a natural process comparable to domestication but in the wild. Their survival as a species is significant proof that cultivating traits like friendliness and cooperative social skills is evolutionarily advantageous in some situations.


Friendliness appears to have aided human evolution:

You’re walking down the street when you notice a stranger. You don’t know him, but his gentle, compassionate face gives the impression that he is trustworthy and dependable. He’s the kind of guy you’d ask for instructions from if you were lost. These kinds of pleasant faces can be found all around us. But why is that?

Our physical appearance isn’t haphazard or superficial. Quite the opposite is true. The proportions and dimensions of the modern human face reveal significant mental shifts. Remember how the physical traits of Belyaev’s Siberian foxes altered as they became more amiable? It’s possible that our forefathers went through the same thing.

Early human evolution may have been selected for friendliness as well, according to fossil records, and the proof is etched all over our faces.

Humans, a kind of hominid known as Homo sapiens, are the planet’s leading primates at the moment. However, we weren’t so isolated as recently as 50,000 years ago. There used to be at least five different hominid species on the planet. Nonetheless, as time passed, humans triumphed and became the most successful species. What gives us the upper hand?

One theory suggests that our forefathers self-domesticated. That is, more sociable persons were selected by evolutionary pressure. However, how do our social abilities provide us an advantage over our cousins? Humans can communicate more effectively, build denser, more stable social structures, and collaborate on developing new technology to improve their ability to get along. Our species became more robust as a result of friendship and community.

Scientists who have studied this phenomenon have discovered solid evidence that an increase in friendliness accompanied the rise of Homo sapiens. Consider this: testosterone, a hormone associated with competitiveness and violence, is also involved in developing specific facial features such as prominent brow ridges and jaws. Looking at the fossil record, we can see how the average brow ridge and jaw shrank as people grew more prosperous. This suggests a relationship between enhanced sociability and our species’ progress.

Other physical markers of domestication can also be seen on modern faces. When you compare human and chimp eyes, you’ll notice that only ours have white spots called sclerae. Another adverse effect of selecting for friendliness is the loss of pigmentation. It is, however, a helpful social adaption. White sclerae make it easy to tell where someone is looking, which is an essential tool in interpersonal communication.


Even with strangers, our brains have evolved to develop strong social relationships:

Flashing lights, blaring music, fluid dancing, and a strong, uncontrollable want to hug everyone in sight. These are some of the recognized adverse effects of using illegal ecstasy. This substance, often known as MDMA, is widely used in parties, nightclubs, and other hedonistic social settings. It’s not difficult to see why. Serotonin and oxytocin, two molecules closely connected to happiness, exhilaration, and other happy emotions, flood the brain when you take a dose.

Buying ecstasy is prohibited in most countries. However, evolution has made it possible for folks seeking pleasant vibes to obtain a boost of serotonin and oxytocin the old-fashioned way. Simply look someone in the eyes.

Social solid relationships became a vital tool for survival as humans evolved to be more kind. After all, there are several advantages to living in a stable, cooperative social environment. Take, for example, the Hadza people of Tanzania. Through mutual trading, this group of hunter-gatherers has been able to sustain their village for generations. Hunters share their kills, gatherers divide their loot, and everyone ends up with plenty.

So, how can humans form bonds? One method is to use drugs such as oxytocin. The amygdala, the part of the brain that processes threats and danger, is disrupted by this neurohormone, which affects thinking. Slowing down the amygdala allows one to be more open to intimacy with others. In reality, studies demonstrate that people given oxytocin have more empathy and are more sensitive to other people’s feelings.

Oxytocin is created naturally in humans during social interactions. For example, both mothers and infants are flooded with this molecule after childbirth to help solidify the parental link. When people encounter strangers, though, oxytocin is released. Simply looking into another person’s eyes causes this substance to be released in the brain. As a result, people appear to be hardwired to develop beneficial social bonds.

This phenomenon aids our species in forming social networks that extend beyond our immediate relatives. In essence, it enabled the formation of a new social category known as the intragroup stranger. This is someone you don’t know but consider a member of your group. Neighborhoods, cities, and countries — all huge communities on which we rely – are made feasible by our goodwill toward strangers within our group.

This bonding, however, has a wrong side, which we’ll look at in the following paragraphs.


Outsiders may appear less human as a result of our deep social bonds:

For millennia, our inherent predisposition for teamwork and kindness has aided our species’ survival. Even though our forefathers relied on one another to survive, our human family is not without conflict and suffering. Take, for example, Rachel’s narrative.

Rachel was born into the Banyamulenge community in the Democratic Republic of the Congo, a small ethnic group known as Africa’s Black Jews. While she had a happy childhood, her adult years were scarred by horrific conflict. Throughout the 1990s, other political and ethnic groups continued to isolate and persecute the Banyamulenge people. The nightmare came to a head in 2004, when an outside rebel group assaulted Rachel’s refugee camp, killing her entire family.

At first glance, this bleak tale appears to cast doubt on our perceptions of human warmth. However, the same evolutionary factors that make us friendly are also responsible for this heinous brutality.

Rachel’s experience is disturbing, but it’s not unusual. The terrible reality is that human history is littered with acts of brutality, war, and genocide. But, without abandoning our view of kindness as an evolutionary advantage, how can we comprehend these savage impulses?

To begin, we must consider the disadvantages of developing strong social relationships. While our brain’s oxytocin sensitivity aids us in empathizing with other members of our group, it also has a negative side effect. In addition, oxytocin makes mammals more aggressive against strangers who are seen as a threat. Consider how a mother bear will tenderly care for her cubs while viciously attacking any neighboring animal that appears suspicious.

As a result, although humans will help and support strangers who are viewed as members of their group, strangers who are perceived as outsiders will receive the opposite reaction. This is partly because our brains perceive outsiders as having less theory of mind. That implies we spend less time empathizing with non-group members’ thoughts, feelings, and experiences. We treat them as less human on a neurological level.

This phenomenon can also be seen on a cultural level. When a powerful group oppresses another, the outsiders are sometimes depicted as non-human animals. This is known as immunization, and it may be seen in everything from propaganda to racist slurs. These portrayals serve to feed the natural desire to despise outsiders.

Nonetheless, violence is not unavoidable. It is possible to generate feelings of shared humanity that energize our finest inclinations through cultivating empathy between groups.


With close, informal touch with others, we can cultivate tolerance:

1941 in Poland. The Nazis are hard at work gathering up Jewish families and putting them in terrible ghettos. Many members of the local populace are intimidated by the occupying forces and do little to help. Andrzej Pitynski, on the other hand, was not going to take it lying down.

Despite not being Jewish, Pitynski risks his life to sneak food to others in need. Even when apprehended and sentenced, he and his wife continue to fight tirelessly to save Jews throughout the war.

What drove the Pitynskis, and hundreds of other heroes like them, to devote their lives to aiding a community that others had dehumanized? Most of these resistors, according to sociologists Pearl and Samuel Oliner, had one thing in common. They all had strong bonds with their Jewish neighbors.

The forces of dehumanization that led to the Holocaust have not vanished. Unfortunately, there are still people who hate and oppress others who are perceived as outsiders worldwide. The alt-right philosophy is a good example. These people have a high Social Dominance Orientation score, which means they feel some groups, such as racial minorities, are intrinsically inferior.

How can society prevent the propagation of such destructive ideas? Some people believe that persons who hold retrograde beliefs should be forcibly suppressed. This strategy, though, could backfire. When humans are threatened, they tend to dehumanize strangers. It’s possible that increasing your sense of vulnerability will increase your outward hatred.

Creating more spaces for non-threatening contact between groups might be a preferable way. Negative feelings that drive hatred are eroded by positive, casual social engagement. For example, later in life, college students who are randomly assigned roommates from various racial origins are reported to be significantly more tolerant of racial diversity. White residents of desegregated neighborhoods were also considerably more inclined to support continued desegregation in the 1940s.

We must ensure that individuals interact across all demographic lines to prevent our societies from sinking farther into enmity. Cities and municipalities in the United States are frequently spatially split at the moment. There are wealthy and impoverished sections, as well as white and black neighborhoods.

However, by actively redesigning cities to encourage connection, Americans can begin to reverse this established division. It’s critical to invest in more mixed-income housing, create more accessible public areas, and remove physical obstacles that divide people. To summarize, it is essential to construct cities where residents are familiar with all of their neighbors.


Our behavior of animals reflects how we treat one another:

Claudine André, a conservationist, had a dilemma during the Second Congo War. Her hometown, Kinshasa, was under assault. Every day, bombs were dropped. Both clean water and reliable energy were scarce. To top it off, André had to look after a dozen bonobos in these difficult circumstances.

André made considerable efforts to keep the delicate apes alive and happy, even if it wasn’t easy. She let them stay in her house and took them to remote woodland every day to play and interact. She started dozens of Kindness Clubs after the war. Local children could meet the bonobos and learn about their lives in these modest sanctuaries.

André had a specific reason for wanting children to meet the bonobos. The cause was straightforward to her. It has the potential to avoid another conflict. Children who learn to respect and adore animals are more likely to look after each other.

For as long as our species has existed, humans have coexisted with other animals. We’ve often utilized animals for food and as employees, but we’ve also thought of them as family. Our devotion to animals is reflected in our ceremonies. Archeologists have discovered ancient burial sites worldwide where our forefathers were buried alongside their canine companions.

People who establish interspecies friendships are more inclined to express generosity to other humans, which should come as no surprise given our deep social interactions with animals. Gordon Hodson and Kristof Dhont, both psychologists, investigated this interaction. According to the researchers, people who assigned more thoughts and feelings to animals also scored higher on tests of tolerance.

Another study, led by Brian Hare and his Ph.D. student Wen Zhou, took a closer look at this occurrence. The scientists asked participants if they agreed that some dog breeds were naturally superior to others in a poll. Those who believed the phrase was accurate also scored well on Social Dominance Orientation tests. That is, they liked human society’s hierarchies as well.

Our perceptions of animals and our relationships with them have ramifications for our perceptions of one another. We could be more likely to tap into our greatest strength, our potential for friendship if we learn to nurture a loving attitude toward all of nature.