MORAL
ORIGINS
ALSO BY CHRISTOPHER BOEHM
Hierarchy in the Forest
Blood Revenge
Montenegrin Social Organization and Values
MORAL
ORIGINS
THE EVOLUTION OF VIRTUE, ALTRUISM, AND SHAME
CHRISTOPHER BOEHM
BASIC BOOKS
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NEW YORK
Copyright © 2012 by Christopher Boehm
Published by Basic Books,
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Text set in 11 point Giovanni by the Perseus Books Group
Library of Congress Cataloging-in-Publication Data
Boehm, Christopher.
Moral origins : the evolution of virtue, altruism,
and shame / Christopher Boehm.
p. cm.
Includes bibliographical references and index.
ISBN 978-0-465-02919-8 (e-book)
1. Ethics, Evolutionary. 2. Virtue. 3. Altruism. 4. Shame. I. Title.
BJ1311.B645 2012
155.7--dc23
2011048896
10 9 8 7 6 5 4 3 2 1
This book is dedicated to
the memory of Donald T. Campbell
CONTENTS
ONE Darwin’s Inner Voice
TWO Living the Virtuous Life
THREE Of Altruism and Free Riders
FOUR Knowing Our Immediate Predecessors
FIVE Resurrecting Some Venerable Ancestors
SIX A Natural Garden of Eden
SEVEN The Positive Side of Social Selection
EIGHT Learning Morals Across the Generations
NINE Work of the Moral Majority
TEN Pleistocene Ups, Downs, and Crashes
ELEVEN Testing the Selection-by-Reputation Hypothesis
TWELVE The Evolution of Morals
EPILOGUE Humanity’s Moral Future
Acknowledgments
Notes
References
Index
DARWIN’S INNER VOICE
1
A NATURAL-BORN HERESY
Queen Victoria’s England provided a most comfortable environment for Christians who loved to take their Bibles literally. Nature was perfect because in just seven days God had made nature perfect. Oceans and fish, predators and prey, all fit together like hands in gloves. And this perfectly tuned natural world was forever fixed and static because Jehovah’s unlimited powers had made it that way.1
Not only that, but the Old Testament’s Adam and Eve were real, if uniquely special people whose divine Maker had created them quite recently. A methodical churchman had actually done the biblical math and concluded that just under six thousand years had elapsed since God had made Eve from Adam’s rib, installed this first pair of humans in His idyllic Garden of Eden, and then left them to their fate. In terms of evolutionary time, this meant that the origin of fallible human choice and our sinful sense of shame—together, these gave us a conscience—had taken place only yesterday or perhaps the day before. However, in the twenty-second year of the devout queen’s reign all of this was about to change—and for many there would be no turning back.
In 1859, Charles Darwin’s On the Origin of Species shook cultured reading publics in Great Britain and elsewhere like an irreverent clap of thunder.2 The initial Darwinian lightning bolt did not strike directly against the sacred moral origins story of Eve, Adam, and the persuasive serpent who seemed to undermine the good works of an otherwise omnipotent Jehovah. Rather, this new scientific thesis introduced to the physical world of animals and plants a theory of gradual but ever-changing transformations that were wholly naturalistic. As a result, the beautiful fit of species to their environments was no longer the work of God; indeed, the banal process of natural selection operated very much as livestock breeders did when with short-term practical objectives they changed the hereditary destinies of the animals they domesticated.
These breeders did their work in a deliberate fashion. They permitted more favorably endowed individuals to flourish, while denying less useful or less aesthetically pleasing individuals the opportunity to reproduce. Robert Darwin, a doctor and a country gentleman, was one of these animal breeders. His thoughtful son—who as a young man seemed to be headed for the ministry—knew that individuals of a domesticated species varied along many dimensions. Cattle varied in their productivity in giving milk; dogs, in their natural tendencies to point and fetch, their degree of docility, and the color of their coats.3 It was only after years of sailing around the world as a professional naturalist that the young Charles Darwin became aware that nondomesticated species were just as variable as their domesticated brethren.4
Darwin’s official job had been to collect museum samples and to describe in minute detail the species of plants and animals on different continents, and all this hard work led, as we know, to a major theory. In his mind, such hereditary variation was something that a natural type of selection could act upon spontaneously: the individuals who were more fit to deal with their environments could reproduce, multiply, and flourish, while those who weren’t, couldn’t. This singular insight was to change the Western world’s notions about nature and even its larger view of the universe.
This brings us to a profound difference between natural selection and the selection practiced by animal breeders. For Darwin, changeable natural environments were doing the mechanical work of triage,5 and unlike either a practical livestock breeder or a purposeful God Almighty, these environments had no intentions whatsoever. They were acting as blind arbiters,6 rather than as deliberate agents who knew what they were doing, and this meant that the perfection of nature was just one big accident. The specter loomed of a scary world, devoid of any ultimate Purpose, that suddenly lacked a protective, omniscient, and omnipotent God whose comforting role it was to help those who faithfully prayed for His assistance.
After the passage of a century and a half, it’s remarkable for any major theory not to be superseded, or at least vastly modified. However, in its basics this blind, mechanical theory of natural selection is still going strong in the world of science.7 If we add “genes” to what Darwin thought of rather intuitively as hereditary variation, the idea of natural environments favoring some variants and selecting against others works just as well in the early twenty-first century as it did in the mid-nineteenth. When we consider the complexities of life processes, the simplicity and explanatory power of the theory are awesome.
INDIVIDUAL COMPETITION DID THE TRICK
As the title tells us, On the Origin of Species was about how species come into being naturally—that is, without any supernatural help. To illustrate Darwin’s thinking, let’s consider a hypothetical. If a primitive bear species had been distributed originally over a restricted, uniform part of North America and then portions of this population began to migrat
e into adjacent areas, as their gene pools became separated, these bear subpopulations might gradually begin to differ because they were coping with different climates or new food sources—until eventually some of them could no longer interbreed. The result might be something like what we have today: black bears, brown bears (including grizzlies), and polar bears.
Darwin’s real-life examples of speciation were taken from all manner of animals and plants, large and small, and in the absence of DNA analysis his scientific stories about the selection pressures that shaped these organisms rang of impeccable logic and sound scholarship. In modern terms, what Darwin’s theory told the world was that potentially changeable natural environments were acting continuously on variation in the gene pools of resident populations. And for this process to do its work, two conditions were needed mechanically: hereditary variation and finite life spans among individuals. The latter was necessary if gene pools were to be modified over generations, for the less fit had to fade away and be replaced if local populations were to evolve to resemble their fittest members.
A special insight about the breeding potential of animals guided Darwin’s theorizing. He founded his entire theory of natural selection on one simple but staggering mathematical realization of late-eighteenth-century English political economist and demographer the Reverend Thomas Robert Malthus:8 if all living organisms were to procreate to their full capacity (think of dogs and cats with their annual litters), in theory within not too many generations the planet would be so exponentially overpopulated that there would be little to eat and, eventually, literally nowhere to stand. Darwin’s beautifully simplified answer to a planet knee-deep in living things was sloganized by evolutionary sociologist Herbert Spencer as the “survival of the fittest,”9 even though Darwin’s theory was more subtle than that.
If the systems of biological evolution that Darwin described so mechanically were devoid of guidance from on high, then somehow they had to “regulate” themselves. As an illustration, if a population became denser, food would become scarcer and indirect competition based on who was more efficient at foraging or predation would intensify. At some point this would limit the population’s growth, and its size would stabilize and remain in equilibrium. It was thus that Darwin’s theory solved Malthus’s problem of potentially unlimited and exponential population growth.
Darwin’s new ideas challenged not only God’s directly manipulative role as portrayed in the Book of Genesis, but also the timeline of Creation. Darwin thought of biological evolutionary processes as being very gradual, and in doing so, he was able to take cues from a different field of study, namely, geology. Increasingly, naturalists like Scottish lawyer and geologist Charles Lyell had been hypothesizing that geological formations changed very gradually over time,10 owing to the action of water or wind. Religious skeptics were coming to understand that these processes had required not a few thousand but millions of years to take place. As geological cues helped Darwin to realize that the various physical landscapes he scrutinized in his travels were far from static, this provided yet another essential ingredient for his dynamic but gradualistic theory of environmentally driven natural selection and species origination.
Thus, the biblical story of instant and permanent Creation was being undermined on a number of fronts, all unified by Darwin into an extremely logical—and exquisitely documented—theory of natural selection. His new theory so rudely challenged the static beliefs of religious fundamentalists that many of them were aroused to personally denounce “evolutionism,” like today’s antiscientific religious believers who try to pick apart the scenarios that evolutionists create and publish. They often assume that a few heretofore-unexplained exceptions can “disprove” an entire, widely accepted theory. But even though to a scientist like myself this logic smacks of desperation, these people have faith on their side, and there are many who are prepared to listen.
WHAT ABOUT HUMAN MORALITY?
Initially, an apprehensive Darwin chose not to write about the greatest controversy of all: the application of his new theory to human beings. But when The Descent of Man was finally published in 1871, the scenario Darwin put together was nothing short of remarkable. Not only did he at least outline what he could of the human origin story in the context of an evolutionary sequence starting with apes, but also in certain areas he even managed to provide important environmental details and specify some likely selection mechanisms. For human physical evolution, particularly of our outsized brains and upright locomotion, Darwin’s hypotheses were daring and, given the dearth of information in his day, keenly prescient. The basic outlines he set down on paper are still valid today.
Another of Darwin’s equally daring hypotheses had to do with the origination of moral behavior and the human conscience—the subject of this book. His treatment of a self-conscious conscience was particularly provocative because now he was bringing his naturalistic approach close to the soul, previously the exclusive purview of the church or, more precisely, of God. Darwin did not take on the problem of how human beings came to have a soul; indeed, the word does not even appear in the lengthy and detailed index for The Descent of Man. But he clearly thought our conscience and moral sense were as “naturally selected” as our large brains, our upright posture, and our general capacity for culture.
As a brilliant and meticulous scientist, Darwin didn’t have the data to make anything like a plausibly scientific case with respect to conscience origins, but he did the best he could, and under the circumstances his best was quite good. In an 1871 passage concerned with instincts of “sympathy,” which is often quoted by contemporary scientists such as evolutionary biologist Jessica Flack and primatologist Frans de Waal and by others who take an interest in moral origins,11 Darwin wrote, “Any animal whatever, endowed with well-marked social instincts, the parental and filial affections being here included, would inevitably acquire a moral sense or conscience as soon as its intellectual powers had become as well developed, or nearly as well developed, as in man.”12
An introspective Charles Darwin waxed eloquent on how the conscience worked, and his own superego was obviously strong and active. Socially, it was this charitable “inner voice” that kept us from getting in trouble with our fellows, Darwin told us, and he wanted badly to explain its evolutionary origin. But all he could tell his readers was that gaining a conscience and hence a sense of morality was, in effect, an inevitable outcome if a species became sufficiently smart and socially sympathetic to reach the human level.
Unfortunately, this gave our uniquely human conscience the evolutionary appearance of being a mere byproduct, a side effect of intelligence and sympathy. This is a position I think we can vastly improve upon with present knowledge, and in the chapters to follow I will bring in some quite specific hypotheses to explain how the conscience evolved and why it did.
THE MYSTERY OF HUMAN GENEROSITY
Darwin tried to answer yet another profound question: Why do human degrees of generosity seem to defy the patently “selfish” principles of natural selection theory? This original puzzle was influentially redefined in modern terms in the 1970s by scholars such as social psychologist Donald T. Campbell and biologists Richard D. Alexander and Edward O. Wilson.13 And for more than three decades now, a major and growing interdisciplinary academic industry has devoted its efforts to resolving the “altruism paradox”—with only partial success. I hope that this book will get us closer to a scientifically satisfying answer.
The historical background for this fascination with altruism is quite interesting. Darwin’s “selfish” theory of natural selection held that individuals were indirectly competing for fitness and that, as we’ve seen, those who were more vigorous or otherwise better adapted for securing food or mates would come out ahead in shaping the hereditary future of their species. This could be explained simply: favored individuals had more surviving and breeding offspring than others in their group or region or wider population. But Darwin also realized that this kind of advant
age could be helped along by family connections because close relatives who naturally helped each other tended to share the same heredity. He didn’t carry this second idea very far, but it turned out to be extremely important.
This became clear a century later when the well-known population geneticist William Hamilton showed through mathematical modeling that selfishly competing individuals could make reasonable personal sacrifices if these benefited their own offspring.14 Because, on average, an individual shares 50 percent of his or her heredity with progeny, investing in offspring helps propagate the genes that individual carries. The same 50 percent rule holds for helping siblings or parents. Being generous to a grandchild or a first cousin (a relationship that involves only a 25 percent genetic similarity) still makes sense if the costs of helping aren’t too high and the benefits are significant. This powerful theory, known as kin selection, can apply to even lesser degrees of kinship as well, as long as the donor’s costs are sufficiently modest and the benefits sufficiently large.
Darwin identified a further problem that continues to perplex scholars today.15 In real life, humans don’t merely assist their close or distant blood kin; they also help people who are unrelated to them—even though from a biological standpoint giving such altruistic assistance will be costly to their fitness because there is no shared heredity. This means that unless these unrelated beneficiaries somehow are reciprocating in something like equal measure, or unless some other type of “compensation” exists, the individuals who take such action may be lowering their own fitness and raising the fitness of their partner. At its simplest, the evolutionary lesson is all too obvious: in theory, generosity should stay within the family because nepotists who refrain from altruism will be able to outcompete the altruists.
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