Kuni was standing out in her yard when she saw a starling fly into the glass windows of her home. The bird was stunned, lying on the ground. Kuni went to comfort it and set it on its feet. The bird didn’t move, so she picked it up and gently tossed it into the air. The bird just fluttered. So Kuni picked the bird up once more and climbed up a tree. Then she wrapped her legs around the tree so that she had both hands free. She carefully unfolded the bird’s wings and spread them wide, holding one wing between the fingers of each hand. She then sent the bird like a tiny airplane out into the air. The bird flew a little way but then sank to the ground. Kuni climbed down and stood watch over the starling for a long time, protecting it from her curious younger siblings. By the end of the day, the recovered bird had flown to safety.

The title of my sermon has probably given it away, but except for that, would you have been surprised to learn that Kuni is not a person, but an ape, and that her home is the Twycross Zoo in Great Britain? It is a rather startling anecdote when you think about it. Kuni doesn’t know how to fly, and yet she reacted to the bird in a way that reveals she could imagine herself into the predicament of this animal quite different from herself, that she could tailor her assistance to the specific situation. Isn’t this what we mean by empathy—the ability to identify with someone in distress? We expect empathy in fellow human beings, but in apes? Is empathy perhaps part of our evolutionary heritage?

We all know that human beings evolved from other animals. But what does that tell us about what it means to be human? Most often when someone refers to our “animal nature” they are referring to the darker side of our nature—our propensity for violence and aggression. To many observers, human altruism and morality represent only a thin veneer of civilization overlaid on these basic animal characteristics. The “veneer theory” gained prominence after World War II which, with its gas chambers and mass executions, showed humanity at its worst. How could civilized people act so savagely? It must have been something in our genetic heritage, something animal-like, that burst through the normal inhibitions, and pushed human decency aside. If we came from apes, then it makes sense that we would act like apes once restraints are lifted—or so the reasoning went.

This pessimistic view of human nature was strengthened in the 1970s and 80s when more was learned about the chimpanzee, presumed to be our closest relative. Observations of chimps in the wild seemed to reveal disheartening parallels between chimpanzee behavior and human behavior at its worst.

Chimpanzee society, it was discovered, is decidedly hierarchical. At the top is the alpha male who dominates all the other chimpanzees in the troop in a descending pecking order. Alpha males obtain their position by overpowering or cowing other males into submission. There are also alpha females, but they usually attain their position by virtue of age or leadership qualities. Among male chimps, power is always up for grabs. It has to be fought for and jealously defended against contenders. In order to rule, alpha males need both physical strength and buddies who will help out when a fight gets hot. Alpha males seldom hold their position for more than four years because subordinate males form coalitions with other males and influential females to challenge the dominant male. Chimp struggles for power can be incredibly brutal, often resulting in the death and dismemberment of the former alpha male.

Frans de Waal, a Dutch primatologist who has studied chimpanzees for 37 years, believes that many aspects of human power dynamics mirror chimpanzee society. In fact, he says that it was only after studying chimps that he really understood human politics. For chimps, staying on top is a matter of a balancing act between forcefully asserting dominance, keeping supporters happy, and avoiding mass revolt. Aren’t there are lots of places in the world where this would seem an apt description of the human political process? And doesn’t the “will to power” with its accompanying payoffs seem to be a prime motivator in many of the struggles within and between nations? Sadly it is also the case that human power struggles often end in death.

If the description of chimpanzee in-group behavior hits a little uncomfortably close to the bone, the way that chimps treat strangers may be even more distressing. Observations of chimps in the wild reveal that chimps are highly territorial. Males regularly go on border patrol and they will also kill members of other chimp communities through highly coordinated group actions against individuals. They will stalk, run down and swiftly overwhelm a victim, who is then viciously and most often, fatally, beaten. Toshida Nishida, who has been observing chimps in the wild of Tanzania for over forty years, believes that all the males of one of his communities were systematically wiped out by neighboring males over a period of twelve years. The winners then claimed the vacant territory and the females in it. Nishida has no doubt that this was targeted, deliberate killing. He observes that chimps of different communities act toward each other as they do toward prey, treating each other as if they belong to another species. This us-versus-them thinking even emerged between chimps who knew each other. Over the years, one community split into a northern and southern group, eventually becoming two separate communities. These chimpanzees had grown up together, played and groomed together, shared meat and reconciled after squabbles. But the factions began to fight nonetheless. Horrified researchers watched as former friends now drank each other’s blood.

Horrifying though such behavior may be, aren’t there parallels with human behavior here as well? Human beings also seem to have a propensity toward in-group identification and xenophobia. And we, too, especially in times of war, dehumanize our enemy—see them as different in kind from us. Furthermore, studies have shown that us-versus-them thinking is remarkably easy to induce in human beings, even in laboratory settings. And the road from dehumanization to murder and torture can be a very short one indeed, as we have all too often regrettably witnessed. And we have also seen how ethnic groups that used to get along reasonably well can all of a sudden turn against each other, as in Rwanda and Bosnia.

Perhaps it’s true, as one observer put it, that the study of chimpanzees reveals that “warfare is in our DNA.” If this is the kind of animal we derived from, perhaps it is an inevitable part of human nature to constantly be struggling against one another, to automatically perceive strangers as other, and to act cooperatively only when we can unite against a common enemy. And if evolution itself turns on survival of the fittest, wouldn’t it make sense that evolution served to enhance the most ruthless aspects of our biological heritage?

Well, leave the chimps behind for a moment and take a journey back in time to visit a certain apartment in 18th century Vienna. Walk in and what do you see? One of the dirtiest, smelliest, most disorderly places imaginable—strewn with rotting food, un-emptied chamber pots, and layers of dust and paper. What kind of person would live in such a place? It probably wouldn’t surprise you to learn that the resident of that apartment looked so slovenly that he was once arrested as a vagrant. And you probably would feel justified in assuming that nothing good could come from such squalor. And yet, this was exactly the environment that gave rise to some of the most enduring musical masterpieces of all time. You see, that apartment was the home and workplace of Beethoven, one of the greatest classical composers to ever live, an undisputed genius of musical form and harmonic structure.

Frans de Waal warns us against what he calls the “Beethoven error;” confusing process with product. Beethoven is enduring proof that beauty and order can arise even from atrocious circumstance. Yet confusion between process and product is exactly the fallacy many people make when it comes to evolution. We think that because natural selection is a cruel, pitiless process of elimination, it must, of necessity, produce cruel and pitiless creatures. But natural selection favors organisms that survive and reproduce, pure and simple. How they accomplish that is left wide open.

And that’s where we come to the other side of the story. You see, chimpanzees are not our only closest relative. Human beings have another ape relative who is equally close to us—the lesser known bonobo. Chimps, human beings and bonobos all evolved from a single forebear. Since bonobos and chimpanzees diverged from each other after human beings diverged from our common lineage, both chimps and bonobos are equally related to us. Bonobos were one of the last large mammals to be discovered—in 1929. Before then bonobos were mistaken as chimps, even though upon close observation they look quite different. The first study of bonobos was published in 1954 and it was limited to a few young bonobos in captivity. Studies of them in the wild came much later. And it is only in the last few years, thanks in large part to the writings of Frans de Waal, that information about the bonobo has begun to influence our view of human nature and its evolutionary heritage.

Bonobos are gentle, empathic creatures. Kuni, the ape who rescued the starling in my opening story, is a bonobo. Among bonobos, there’s no deadly warfare, little hunting, and enormous amounts of sex. That latter characteristic may have something to do with how long it has taken for information about the bonobo to become widely known. de Waal calls bonobos “kama sutra primates.” Not only do they have sex in an astonishing variety of positions, on average every hour and a half, but they also have sex with both genders in virtually all possible partner combinations except between mother and son. Sex for the bonobo, unlike for chimpanzees, serves many functions beyond reproduction—bonding, easing of intragroup tensions, and, one would have to say, pure pleasure. Bonobos, in short, do not make good candidates for family nature films.

Bonobo society is matrifocal rather than patriarchal. Female bonobos rule, not through a single alpha individual, as in the chimps, but through a female collective, a cooperative team. Bonobo females are highly sociable and they spend quite a lot of time in female bonding through grooming and sex. There are females who are more dominant than others but their power comes from seniority and their dominance is measured by access to food rather than to mates. In fact female bonobos gain more power the older they become. Dominance struggles are far less common among bonobos than chimps. Younger females are kept in their place not by fighting but by much more subtle means, such as refusing to share food, rejecting an overture, or by walking away from a grooming attempt. Male bonobos derive their relative status in the group from their mother’s position. Interestingly male bonobos live longer, healthier lives than their chimp cousins—scientists speculate that is because they are less subject to the stress of continuous power struggles.

Bonobos are also very different from chimps when it comes to out-group behavior. In the wild, bonobo ranges often overlap with one another and there is often peaceful mingling at the borders. Different communities of bonobos may spend several days together, playing, grooming, and, of course—it being bonobos—having sex. Bonobos seem to have escaped one of humanity’s worst traits—our xenophobia and tendency to discount the lives of those who are strangers. Could that be because, as de Waal speculates, female bonobos copulate freely with whomever they want, making male territorial competition obsolete? There is no need to capture females who are already happy to have sex and, moreover, because of the intermingling, neighboring groups may include one’s blood relatives. Aggression in this case would be counterproductive to survival of one’s genes.

If chimps represent the demonic side, do bonobos represent the better angels of human nature? They certainly seem to exhibit a degree of mutuality and kindness not seen in chimps. I already described how Kuni treated the injured bird that flew into her enclosure. And take the case of Kidogo, who because of a heart condition, lacked the normal stamina and self-confidence of a grown bonobo. When he was first introduced to a new zoo, he was confused and couldn’t find his way in the tunnel system. Other bonobos stepped in, took him by the hand and led him wherever the keepers wanted him to go. Kidogo came to rely on their help—when lost he would utter distress calls and others would quickly come to calm him and act as guides. It is worth noting that none of these other bonobos were related to Kidogo, nor could they expect some kind of reciprocal assistance from him in his frail condition.

Or this story from the San Diego zoo. The six foot moat in front of the bonobo enclosure had been drained for cleaning. After it was scrubbed and the apes released, the keepers went to turn on the water to refill it, when all of a sudden an old male, Kakowet, came to their window, screaming and frantically waving his arms to catch their attention. Kakowet had been around enough years to be familiar with the cleaning routine. It turned out that several young bonobos had entered the dry moat and were unable to climb up the slick walls. The keepers had to provide a ladder to get them out. If those young bonobos had been left in the moat as it filled with water, they would have drowned. Apes cannot swim.

There is much more that could be said about these two closest relatives of ours—and that there may be future sermonic excursions into what they have to teach us. But let me close by considering the question—which do we most resemble, the chimp or the bonobo? Are human beings more like the ruthless, competitive chimp or the empathic, cooperative bonobo? It’s obvious that human nature is a mixture of the two. Yes, we are capable of the cruelest aggression. Yet we are also capable of self-denying altruism. But is one side truer of human nature? de Waal deeply believes that the view that our competitive side is most authentic is deeply flawed. He points out that even the chimpanzee is a social animal, that even chimps have found ways to temper their aggression in order to live in communities. Some degree of cooperation is necessary for their survival. Primates, of which we are one, belong to a category of animals scientists call “obligatorily gregarious.” We are relational by nature, and that is even more true of human beings than our ape cousins because of our longer period of vulnerable childhood. We are the product of opposing forces—the need to look out for our own interests and the need to get along with others—but we are not just automatons carrying out nature’s genetic programs. Although human behavior probably is determined to a greater degree than we like to admit by ancient drives for power, sex, food and safety, it is also modified by experience and learning, by intelligence and decision making, by wisdom and insight. We are adaptable, innovative, and as the case of Beethoven reminds us, hugely creative. We do fight and kill and maim, but we also create transporting music and awe-inspiring art. We make war, but we also make love.

At the beginning of the twenty first century, human beings face tremendous challenges—the threat of nuclear proliferation, the pressures of population and depletion of natural resources, and, not the least, the destruction of the ecosystem. Sadly, it is predicted that by the year 2040 every suitable ape habitat will be gone. All the wild great apes—not just the chimps and bonobos, but also the gorillas and orangutans—will be gone. And what of us? It is now imperative that human beings become more adept at cooperation. We absolutely must overcome the part of our evolutionary heritage that makes it hard for us to identify with outsiders and to acknowledge the needs of those we don’t know. More than ever before, we will need to draw on and strengthen the social side of our biological nature to create ever widening circles of empathy and mutuality. It will be hard, but it is not beyond our power. To echo Carl Sandburg, we may have a menagerie inside our ribs, under our bony heads, but we’ve got something else, too—a man-child heart, a woman child heart, a father and mother and lover. And we are the keepers of the zoo. We have the power to choose, to make our hopes and dreams for a better way come true. We must let love be our guide.