Our breath catches and we jump in fear at the sight of a snake. We pause and marvel at the sublime beauty of a sunrise. These reactions are no accident; in fact, many of our human responses to nature are steeped in our deep evolutionary pastwe fear snakes because of the danger of venom or constriction, and we welcome the assurances of the sunrise as the predatory dangers of the dark night disappear. Many of our aesthetic preferencesfrom the kinds of gardens we build to the foods we enjoy and the entertainment we seekare the lingering result of natural selection.
In this ambitious and unusual work, evolutionary biologist Gordon H. Orians explores the role of evolution in human responses to the environment, beginning with why we have emotions and ending with evolutionary approaches to aesthetics. Orians reveals how our emotional lives today are shaped by decisions our ancestors made centuries ago on African savannas as they selected places to live, sought food and safety, and socialized in small hunter-gatherer groups. During this time our likes and dislikes became wired in our brains, as the appropriate responses to the environment meant the difference between survival or death. His rich analysis explains why we mimic the tropical savannas of our ancestors in our parks and gardens, why we are simultaneously attracted to danger and approach it cautiously, and how paying close attention to nature’s sounds has resulted in us being an unusually musical species. We also learn why we have developed discriminating palates for wine, and why we have strong reactions to some odors, and why we enjoy classifying almost everything.
By applying biological perspectives ranging from Darwin to current neuroscience to analyses of our aesthetic preferences for landscapes, sounds, smells, plants, and animals, Snakes, Sunrises, and Shakespeare transforms how we view our experience of the natural world and how we relate to each other.
|Publisher:||University of Chicago Press|
|Product dimensions:||5.90(w) x 9.10(h) x 0.90(d)|
About the Author
Gordon H. Orians lives in Seattle, where he is professor emeritus of biology at the University of Washington. He is the author or editor of several books, including, most recently, Red-Winged Blackbirds: Decision-making and Reproductive Success and Life: The Science of Biology.
Read an Excerpt
Snakes, Sunrises, and Shakespeare
How Evolution Shapes Our Loves and Fears
By Gordon H. Orians
THE UNIVERSITY OF CHICAGO PRESSCopyright © 2014 The University of Chicago
All rights reserved.
Whistling for Honey
How old is the human sweet tooth, and why do we crave sweet things?
As it happens, these two questions will take us far from our distant ancestors and their hunger for wild honey. They will lead us to still other questions, questions that have to do with the emotions the natural world arouses in us—yearning and revulsion, joy and fear—and how those emotions have shaped every aspect of our lives.
But our story starts here, following a prehistoric hunter somewhere in Africa, whistling for honey.
Until humans figured out how to refine sugar from plants such as sugarcane and sugar beets, we had to steal from creatures skilled at concentrating the nectar of flowers into a rich source of food: honeybees. Our ancestors learned how to rob the nests of wild bees at least twenty thousand years ago—rock art of that age survives in Zimbabwe (figure 1.1) The image left behind on the rock face clearly shows a person smoking a hive to get honey.
Our African ancestors must have found honey a sweet temptation: it was nutritious, delicious, and easy to digest. But bee colonies are uncommon on the African savanna. In order to find and exploit them, prehistoric humans relied on an unusual partner that also benefited by leading them to the hives. That partnership has persisted into modern times; we can still witness it today in several African tribes, among them the Boran of northeast Kenya.
Just before setting off in search of honey, Boran honey hunters give a specific, loud whistle, known as the fuulido (figure 1.2). If they're in luck, there will be a return call from a bird with a fuulido of its own. The caller is a greater honeyguide, a small bird; its Latin name, Indicator indicator, reflects its value to humans. The honeyguide repeats its distinctive "follow me" call, and begins to escort the Boran hunters to a bee's nest, pausing frequently to allow the hunters to catch up. Most astonishing, upon arriving at the tree where the bees have nested, the honeyguide perches and sings a special "indication" song. The bird escort remains nearby as the hunters disperse the bees and claim the prize of the honeycomb. In gratitude, they always reward their navigator by leaving behind some honeycomb. Unlike most birds, honeyguides can digest wax; they feast on it along with the honey and bee larvae lodged in the comb, but honeyguides are too small and weak to open bees nests. They depend on humans to do it for them, just as people depend on honeyguides to help them find the nests.
This unusual mutually beneficial partnership features in the myths of many African savanna-dwelling tribes. Our ancestors probably gorged on honey whenever they could find it. Honey was a nutritional and energy bonanza, a precious fuel for our large hominid brains. But the rarity of hives in the savannas made it impossible to gather enough to grow fat on this rich resource.
By contrast, walk the aisles of a modern supermarket and count the staggering variety of sweet and sugary foods. We modern humans are blessed and cursed by uninterrupted access to sweets, and we have become slaves to our sweet tooth. Hardwired with our ancestors' cravings for sugar-rich foods, we're unable to resist. We are also adapted to an environment where food was sometimes abundant and sometimes scarce. When it is abundant, we lay on fat for the future hard times. Today, hard times rarely come. As a result, obesity is now a serious health problem throughout the developed world and an increasing problem in developing nations.
It turns out that a fondness for sugar is just one trait our ancestors bequeathed to us. Our ancestors' responses to environmental challenges—unpredictable sources of food, ever-present predators, extremes of weather—have molded our modern emotional lives. They are a central theme of this book. Evolutionary psychologists tell us that whenever we're incited to act by strong emotions, positive or negative, chances are good those actions were of great evolutionary importance. Responding appropriately to stimuli meant the difference between surviving or not, leaving offspring or not.
Our ancestors came to prefer or "like" beneficial objects and events in nature that increased their chance of surviving and passing on their genes to their children—in short, evolution by natural selection. Conversely, they came to avoid or "dislike" objects and events that were threatening and decreased their chances of surviving and reproducing. Over time, these likes and dislikes became wired in the human brain. As a result, we have a taste for honey and a nearly universal fear of carnivores with big teeth. Science allows us to trace these ancient emotions and find the adaptation in what we find beautiful and what fills us with revulsion and fear. We can better understand how we interact emotionally with our environment by viewing our behavior through an evolutionary lens that focuses on our ancestors.
This book records the results of my efforts to find out how our emotional lives bear the imprint of decisions our ancestors made long ago on the African savanna as they selected places to live, sought food and safety, and socialized in small hunter-gatherer groups. I hope to convince you that the impressions are many and deep and the rewards for this new understanding as useful as the honeyguides are to the Boran people.
How I Came to These Questions
My search for an environmental basis to emotions and aesthetics began the year I was seven, when I discovered the world of birds. My family rented a cabin on a lake in northern Wisconsin, and I was captivated by the call of the common loon. I soon began to record observations of birds I saw; those notebooks still sit on the shelves of my university office. When I was about thirteen, I joined birders in the Milwaukee, Wisconsin chapter of the Audubon Society. A few of them were professional ornithologists. At some moment, I put two and two together—people were actually paid to study birds! I decided then that I would go to college, major in biology, and become a professional biologist. I did exactly that. I became a behavioral ecologist because I was interested in the decisions birds like honeyguides must make to be successful—how they select habitats, search for food and decide what to eat, chose their mates, and invest in their offspring.
In my young adulthood I never questioned my strong attraction to birds. I simply enjoyed them. But as I matured as an evolutionary biologist, I began to think deeply about human emotional responses to nature. My thoughts, as well as those of many other people, were stimulated by Edward O. Wilson's Sociobiology: The New Synthesis, published in 1975. Wilson helped me recognize that the decisions I was studying with birds govern our lives as well. My curiosity has led me in surprising directions and caused me to learn about topics that I knew little or nothing about, but all examined through an evolutionary lens.
Like most other people, I have been deeply moved by the roar of ocean waves, lightning-filled skies, and claps of thunder. Views of sunsets and beautiful spreading trees have given me pleasure. The smell and sight of rotting flesh repulse me. Yet, why we respond emotionally the way we do to the cheerful songs of birds or the glow of sunshine—this was a foreign topic, one that my scientific colleagues and I seldom pursued in depth.
Emotions through an Evolutionary Lens
Evolutionary biologists like me came to the party late. For centuries, artists and philosophers had explained the human emotional response to beauty by pointing to human culture and works of art. We must look primarily at our responses to human creations, they argued, to understand our feelings and the basic structure of our emotional lives. Daring to explain our emotional responses to nature in evolutionary terms can provoke outrage among artists and nature lovers. In the nineteenth century, John Keats despaired that Isaac Newton had forever sullied the beauty and mystique of rainbows by explaining how they were formed. In his poem Lamina (1820) he complained that Newton had destroyed a rainbow by unweaving it. Keats was not alone, then or now (figure 1.3). Even today, most people resist having their emotions explained because they believe that explaining them will destroy their inherent wonder. Such defiance is so pervasive that Richard Dawkins wrote Unweaving the Rainbow: Science, Delusion, and the Appetite for Wonder (its title taken from the line in Keats's poem), which addressed this false perception.
Scientists marvel at rainbows even though they know that physical processes generate them, just as most of us intensely enjoy physical intimacy even though we understand its biological function. Yet, many people are hostile to the idea that our emotions evolved because they positively influenced the survival and reproductive success of our ancestors. They resist the idea that science might better explain our emotions than philosophy, art, or common sense.
But what are emotions? We all know, or think we know, much about emotions. We know that they powerfully affect our behavior and thoughts; that some of our emotions are pleasant, others are not. Yet, as Fehr and Russell describe, "everyone knows what an emotion is, until asked to give a definition." We struggle to define them. Fortunately, we can set aside the definitional problem and study emotions directly. In this book I will draw upon self-reports (rating scales, questionnaires) and upon physiological measures of emotions. By examining this evidence we will develop a deeper understanding of what emotions are than we could gain by trying to come up with a definition.
To understand our emotional responses to the environment we shall explore in greater depth why we even have emotions at all. That exploration, covered in the next two chapters, will set the stage for later discussions of how humans perceive the environment with our senses and why our emotional responses to nature are so diverse. I hope to demonstrate that an evolutionary approach to human behavior gives us a creative way to think about our emotional lives and a way to answer many questions we have about them. The evolutionary approach to why we have the emotions and aesthetic responses we do differs strikingly from the prevailing view held by Western academics. We will be concerned primarily with the so-called basic emotions—pleasure, anger, fear, pain, surprise, and disgust. We will pay little attention to the social emotions—love, guilt, shame, embarrassment, pride, envy, and jealousy.
In this book I share with you the results of my personal odyssey to understand our emotional responses to nature and how scientists explain them. Our emotional roots lie in the African savannas, back where we first followed honeyguides to a sweet feast of honey, while keeping an eye out for lions that might dine on us. We will examine how an understanding of our evolutionary history helps explain why we respond emotionally, why the reasons for our responses are often hidden from us, and how our brains evolved to make decisions that improve our survival and reproductive success. Understanding these emotions is particularly important today when we live and respond emotionally to a complex environment that differs dramatically from the one our ancestors lived in until very recently. I will also explore how the experience of our emotional responses influences both what we do to the environment as well as what the environment does to us.
The current traits of organisms are the result of their history because evolutionary processes cannot anticipate what the next week, century, or geological era will look like. For modern humans, this means that some of the emotional responses to environments that served our ancestors well may no longer be adaptive in today's industrial societies. For example, we still dream about primeval spiders and snakes rather than about more pervasive modern threats like guns, nuclear weapons, and climate change. Evolutionary insights may help us identify and explain why some elements of our responses are no longer adaptive.
My explorations of human-environment interactions have been both challenging and enjoyable. I hope to convey at least some of that pleasure and excitement to you and to demonstrate that we may be able to use our improved understanding of the roots of our emotional lives to make better decisions today. And understanding ourselves better is, itself, a rich source of pleasure.CHAPTER 2
Ghosts of the African Savanna
We respond with strong feelings to the world around us. We react to some objects, places, and events with pleasure, and call them beautiful; others arouse feelings of fear, disgust, or horror, and we call them ugly. But why do we have this aesthetic sense?
Intellectual thinkers have speculated about the origins and meanings of an aesthetic sense at least since the early sixth century BC in Greece, but Baumgarten's Aesthetica, published in 1750, established the science of the sense experience. It was Baumgarten who gave us the word "taste" in the sense of the human ability to judge what is good. This view of an aesthetic sense opened the way to the scientific study of emotions in the nineteenth century by such men as Charles Darwin, William James, and Wilhelm Wundt.
As early as 1785 the Scottish philosopher Thomas Reid recognized that our emotions might have evolved because they were useful:
By a careful examination of the objects which Nature hath given this amiable quality (of beauty), we may perhaps discover some real excellence in the object, or at least some valuable purpose that is served by the effects it produces upon us. This instinctive sense of beauty, in different species of animals, may differ as much as the external sense of taste, and in each species be adapted to its manner of life.
In this remarkable passage, written seventy years before Chares Darwin published On the Origin of Species, Reid proposes that the aesthetic senses of animals are likely to be related to their relationships with their environment. He suggests that animal and human emotional responses evolved because of benefits that accompanied them.
A generation later, Darwin would show how natural selection, acting over millions of years, could produce structures beautifully fitted for a specific task: eyes for seeing, ears for hearing, wings for flying. But could the human mind, with its powerful emotions, evolve in the same way? Darwin thought it had. Thirteen years after the publication of his 1859 masterwork, he published The Expression of the Emotions in Man and Animals. It was lavishly illustrated, with engravings showing the human facial muscles, a dog with its hackles raised, a grimacing baboon, a sulky chimpanzee—as well as many images of people. Some of the images were photographs by a French physiologist, Guillaume-Benjamin-Amand Duchenne, published with his 1862 book Mécanisme de la Physionomie Humaine, ou Analyse Electro-physiologique de l'Expression des Passions.
Duchenne used a device he had originally developed to investigate the muscles that control the hand to find the muscles responsible for creating particular expressions. He applied an electrical current to the facial muscles of a number of different test subjects. He also took photographs of the same people with blank expressions, and others where they were attempting to simulate expressions without the aid of the probes (figure 2.1).
At this time, Darwin was forming his own ideas about the expression of emotions in humans. He was fascinated by Duchenne's photos and wondered whether the expressions Duchenne had elicited from his patients were universal, whether certain muscle movements of the face always accompanied the same emotional state, in other words, whether there were universal expressions of human emotions. Did a certain grimace always mean disgust? To find out, he conducted experiments on his own—on the guests at his own dinner parties.
Excerpted from Snakes, Sunrises, and Shakespeare by Gordon H. Orians. Copyright © 2014 The University of Chicago. Excerpted by permission of THE UNIVERSITY OF CHICAGO PRESS.
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Table of Contents
Chapter 1. Whistling for Honey
Chapter 2.Ghosts of the African Savanna
Chapter 3. The High Cost of Learning
Chapter 4. Reading the Landscape
Chapter 5. The Snake in the Grass ( . . . and Other Hazards)
Chapter 6. Settling Down and Settling In
Chapter 7. A Ransom in Pepper
Chapter 8.The Musical Ape
Chapter 9. The First Sniff
Chapter 10. Ordering Nature
Chapter 11. The Honeyguide and the Snake: Embracing Our Ecological Minds