Full House +xtras
These lists of error could go on forever, but let me close this section with two striking examples representing the pinnacle (there we go with progress metaphors again) of fame and achievement in the domains of popular and professional life.
* Popular culture's leading version: Psychologist M. Scott Peck's _The Road Less Traveled_, first published in 1978, must be the greatest success in the history of our distinctive and immensely popular genre of "how-to" treatises on personal growth. This book has been on the _New York Times_ best-seller list for more than six hundred weeks, placing itself so far in first place for total sales that we need not contemplate any challenge in our lifetime. Peck's book includes a section titled "The Miracle of Evolution" (pages 263-68).
Peck begins his discussion with a classic misunderstanding of the second law of thermodynamics:
The most striking feature of the process of physical evolution is that it is a miracle. Given what we understand of the universe, evolution should not occur; the phenomenon should not exist at all. One of the basic natural laws is the second law of thermodynamics, which states that energy naturally flows from a state of greater organization to a state of lesser organization . . . . In other words, the universe is in a process of winding down.
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But this statement of the second law, usually portrayed as increase of entropy (or disorder) through time, applies only to closed systems that receive no inputs of new energy from exterior sources. The earth is not a closed system; our planet is continually bathed by massive influxes of solar energy, and earthly order may therefore increase without violating any natural law. (The solar system as a whole may be construed as closed and therefore subject to the second law. Disorder does increase in the entire system as the sun uses up fuel, and will ultimately explode. But this final fate does not preclude a long and local buildup of order in that little corner of totality called the earth.)
Peck designates evolution as miraculous for violating the second law in displaying a primary thrust toward progress through time:
The process of evolution has been a development of organisms from lower to higher and higher states of complexity, differentiation, and organization . . . . [Peck then writes, in turn, about a virus, a bacterium, a paramecium, a sponge, an insect, and a fish—as if this motley order represented an evolutionary sequence. He continues:] And so it goes, up the scale of evolution, a scale of increasing complexity and organization and differentiation, with man who possesses an enormous cerebral cortex and extraordinarily complex behavior patterns, being, as far as we can tell, at the top. I state that the process of evolution is a miracle, because insofar as it is a process of increasing organization and differentiation it runs counter to natural law.
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Peck then summarizes his view as a diagram (redrawn here as Figure 2), a stunning epitome of the grand error that the bias of progress imposes upon us. He recognizes the primary fact of nature that stands so strongly against any simplistic view of progress (and, as I shall show later in this book, debars the subtler versions as well)—rarity of the highest form (humans) versus ubiquity of the lowest (bacteria). If progress is so damned good, why don't we see more of it?
Peck tries to pry victory from the jaws of defeat by portraying life as thrusting upward against an entropic downward tug:
The process of evolution can be diagrammed by a pyramid, with man, the most complex but least numerous organism, at the apex, and viruses, the most numerous but least complex organisms, at the base. The apex is thrusting out, up, forward against the force of entropy. Inside the pyramid I have placed an arrow to symbolize this thrusting evolutionary force, the "something" that has so successfully and consistently defied "natural law" over millions upon millions of generations and that must itself represent natural law as yet undefined.
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Note how this simple diagram encompasses all the major errors of progressivist bias. First, although Peck supposedly rejects the most naive version of life's ladder, he places an explicit linear array right under his apex of progress as the motor of upward thrusting. Two features of this re-introduced ladder reveal Peck's lack of attention and sympathy for natural history and life's diversity. I am, I confess, galled by the insouciant sweep that places only "colonial organisms" into the enormous domain between bacteria and vertebrates—where they must stand for all eukaryotic unicellular organisms and all multicellular invertebrates as well, though neither category includes many colonial creatures! But I am equally chagrined by Peck's names for the prehuman vertebrate sequence: fish, birds, and animals. I know that fish gotta swim and birds gotta fly, but I certainly thought that they, and not only mammals, were called animals.
Second, the model of life's upward thrust versus inorganic nature's downward tug allows Peck to view progress as evolution's most powerful and universal trend, even against the observation that most organisms don't get very far along the preferred path: against so powerful an adversary as entropy, all life must stand and shove together from the base, so that the accumulating force will push a favored few right up to the top and out. Squeeze your toothpaste tube _from the bottom_, just as Mom and the dentist always admonished (arid so few of us do), and the pressure of the whole mass wilt allow a little stream to reach an utmost goal of human service at the top.
Peck ends this section with a crescendo based on one of those forced and fatuous images that sets my generally negative attitude toward this genre of books. Human life and striving become a microcosm of life's overall trend to progress. The force of entropy (also identified as our own lethargy) still pushes down, but love, standing in for the drive of progress (or are they the same?), drives us from the low state of "undeveloped spirituality" toward the acme, or pyramidal point, of "spiritual competence." Peck concludes by writing, "Love, the extension of the self, is the very act of evolution. It is evolution in progress. The evolutionary force, present in all of life, manifests itself in mankind as human love. Among humanity love is the miraculous force that defies the natural law of entropy." Sounds mighty nice and cozy, but I'll be damned if it means anything.
* A similar vision from the professional heights. My colleague E. O. Wilson is one of the world's greatest natural historians. If anyone understands the meaning and status of species and their interrelationships, this unparalleled expert on ants, and tireless crusader for preservation of biodiversity, should be the paragon. I enjoyed his book _The Diversity of Life_ (1992), and reviewed it favorably in the leading British journal Nature (Gould, 1993). Ed and I have our disagreements about a variety of issues, from sociobiology to arcana of Darwinian theory, but we ought to be allied on the myth of progress, if only because success in our profession's common battle for preserving biodiversity requires a reorientation of human attitudes toward other species—from little care and maximal exploitation to interest, love, and respect. How can this change occur if we continue to view ourselves as better than all others by cosmic design?
Nonetheless, Wilson uses the oldest imagery of the progressivist view in epitomizing the direction of life's history as a series of formal Ages (with uppercase letters, no less)—a system used by virtually all popular works and textbooks in my youth, but largely abandoned (I thought), for reform so often affects language first (as in our eternal debates about political correctness and the proper names for groups and genders), and concepts only later:
They [arthropods as the first land animals] were followed by the amphibians, evolved from lobe-finned fishes, and a burst of land vertebrates, relative giants among land animals, to inaugurate the Age of Reptiles. Next came the Age of Mammals and finally the Age of Man.
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These words do not represent a rhetorical slip into comfortable, if antiquated, phraseology, for Wilson also provides his explicit defense of progress, ending with a line that I found almost chilling:
Many reversals have occurred along the way, but the overa
ll average across the history of life has moved from the simple and few to the more complex and numerous. During the past billion years, animals as a whole evolved upward in body size, feeding and defensive techniques, brain and behavioral complexity, social organization, and precision of environmental control.... Progress, then, is a property of the evolution of life as a whole by almost any conceivable intuitive standard, including the acquisition of goals and intentions in the behavior of animals. It makes little sense to judge it irrelevant. Attentive to the adjuration of C. S. Peirce, let us not pretend to deny in our philosophy what we know in our hearts to be true.
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Peirce may have been our greatest thinker, but his line in this context almost sounds scary. Nothing could be more antithetical to intellectual reform than an appeal _against_ thoughtful scrutiny of our most hidebound mental habits—notions so "obviously" true that we stopped thinking about them generations ago, and moved them into our hearts and bosoms. Please do not forget that the sun really does rise in the east, move through the sky each day, and set in the west. What knowledge could be more visceral than the earth's central stability and the sun's subordinate motion?
Darwin was born on the same day as Lincoln, and "officially" inaugurated the revolution that bears his name when he published the _Origin of Species_ in 1859. During the centennial celebrations in 1959, the great American geneticist H. J. Muller dampened festivities with an address titled "One Hundred Years Without Darwin Are Enough." Muller treated the revolution's failure to penetrate at two opposite ends of a spectrum—creationism's continuing hold over much of American pop culture, and limited understanding of natural selection among well-educated people content with the factuality of evolution.
But I think that something even larger, and standing in the middle of this spectrum, has always ranked as the greatest impediment to completing the Darwinian revolution. Freud was right in identifying suppression of human arrogance as the common achievement of great scientific revolutions. Darwin's revolution—the acceptance of evolution with _all_ major implications, the second blow in Freud's own series—has never been completed. In Freud's terms, the revolution will not be fulfilled when Mr. Gallup can find no more than a handful of deniers, or when most Americans can give an accurate epitome of natural selection. Darwin's revolution will be completed when we smash the pedestal of arrogance and own the plain implications of evolution for life's nonpredictable nondirectionality—and when we take Darwinian topology seriously, recognizing that _Homo sapien_, to recite the revised litany one more time, is a tiny twig, born just yesterday on an enormously arborescent tree of life that would never produce the same set of branches if regrown from seed. We grasp at the straw of progress (a desiccated ideological twig) because we are still not ready for the Darwinian revolution. We crave progress as our best hope for retaining human arrogance in an evolutionary world. Only in these terms can I understand why such a poorly formulated and improbable argument maintains such a powerful hold over us today.
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Different Parsings, Different Images of Trends
Fallacies in the Reading and Identification of Trends
The more important the subject and the closer it cuts to the bone of our hopes and needs, the more we are likely to err in establishing a framework for analysis. We are story-telling creatures, products of history ourselves. We are fascinated by trends, in part because they tell stories by the basic device of imparting directionality to time, in part because they so often supply a moral dimension to a sequence of events: a cause to bewail as something goes to pot, or to highlight as a rare beacon of hope.
But our strong desire to identify trends often leads us to detect a directionality that doesn't exist, or to infer causes that cannot be sustained. The subject of trends has inspired and illustrated some of the classic fallacies in human reasoning. Most prominently, since people seem to be so bad at thinking about probability and so prone to read pattern into sequences of events, we often commit the fallacy of spotting a "sure" trend and speculating about causes, when we observe no more than a random string of happenings.
In the classic case, most people have little sense of how often an apparent pattern will emerge in purely random data. Take the standard illustration of coin flipping: we compute the probability of sequences by multiplying the chances of individual events. Since the probability for heads is always 1/2, the chance of flipping five heads in a row is 1/2 X 1/2 X 1/2 X 1/2 X 1/2, or one in thirty-two—rare to be sure, but something that will happen every once in a while for no reason but randomness, Many people, however, particularly if they are betting on tails, will read five heads in a row as _prima facie_ evidence of cheating. People have been shot and killed for less—in life as well as in Western movies.
In my favorite, more subtle example of the same error, T. Gilovich, R. Vallone, and A. Tversky debunked a phenomenon that every basketball fan and player absolutely "knows" to be true—"hot hands," or streaks of successive baskets, magic minutes of "getting into the groove" or "finding the range," when every shot hits. The phenomenon sounds so obvious: when you're hot you're hot, and when you’re not you're not. But "hot hands" does not exist. My colleagues studied every basket made by the Philadelphia 76ers for more than a season. They made two debunking discoveries: first, the probability of making a second basket did not rise following a successful shot; second, and more important, the number of "runs," or successful baskets in sequence, did not exceed the predictions of a standard random, or coin-tossing, model. Remember that, on average, you will flip five heads in a row once in every thirty-two sequences of five tosses. We can, by analogy, compute expected runs for any basketball player. Suppose that Mr. Swish, a particularly good shooter, succeeds in 60 percent of his field-goal attempts. He should then notch six baskets in a row once every 20 sequences or so (0.6 X 0.6 X 0.6 X 0.6 X 0.6 X 0.6, for 0.047, or 4.7 percent). If Swish's actual play includes sequences of six at about this rate, then we have no evidence for hot hands, but only for Swish playing in his characteristic manner for each shot independently. Gilovich, Vallone, and Tversky found no sequences beyond the range of random expectations.
My colleague Ed Purcell, a Nobel Prize winner in physics but just a keen baseball fan in this context, then did a similar study of baseball streaks and slumps, and we published the results together (Gould, 1988). Purcell found that among all runs, the subject of so much mythology about heroes (and goats), only one record stands beyond reasonable probability, and should not have happened at all—Joe DiMaggio's fifty-six-game hitting streak in 1941—thus validating the feeling of many fans that DiMaggio's splendid run is the greatest achievement in modern sports (and exonerating all the poor schlumps whose runs of failure lie entirely within the expectations of their characteristic probabilities!).
As one final example, probably more intellectual energy has been invested in discovering (and exploiting) trends in the stock market than in any other subject—for the obvious reason that stakes are so high, as measured in the currency of our culture. The fact that no one has ever come close to finding a consistent way to beat the system—despite intense efforts by some of the smartest people in the world—probably indicates that such causal trends do not exist, and that the sequences are effectively random.
In the second most prominent fallacy about trends, people correctly identify a genuine directionality, but then fall into the error of assuming that something else moving in the same direction at the same time must be acting as the cause, This error, the conflation of correlation with causality, arises for the obvious reason (once you think about it) that, at any moment, oodles of things must be moving in the same direction (Halley's comet is receding from earth and my cat is getting more ornery)—and the vast majority of these correlated sequences cannot be causally related. In the classic illustration, a famous statistician once showed a precise correlation between arrests for public drunkenness and the number of Baptist preachers in nineteenth-century America. The correlation is real and intense, but we
may assume that the two increases are causally unrelated, and that both arise as consequences of a single different factor: a marked general increase in the American population.
The error detailed in this book has not often been named or identified, but may be just as prominent in our fallacious thinking about trends. I shall focus on two central examples from two dramatically different cultural realms: "Why does no one hit 0.400 anymore in baseball?" and "How does progress characterize the history of life?" These are classic trends, in the sense that each encapsulates the essence and history of an important institution, and both have moral implications—one, in baseball, apparently trying to tell us that something about modern life causes excellence, or old-fashioned virtue, to degenerate; the other, for life, providing our necessary solace and excuse for continuing to view ourselves as lords of all.
I shall not use the juxtaposition of these examples to present pap and nonsense about how life imitates baseball, or vice versa. But I will show that the same error has led us to view both trends the wrong way round. Straighten out the fallacy, and you will see that the disappearance of 0.400 hitting illustrates the increasing excellence of play in baseball (however paradoxical such a claim may sound at first)—while life, on the other hand, shows no general thrust to improvement, but just adds an occasional exemplar of complexity in the only region of available anatomical space, while maintaining, for more than 3 billion years, an unvarying bacterial mode. Baseball has improved, but life has always been, and will probably always remain until the sun explodes, in the Age of Bacteria.