Shadows of Forgotten Ancestors (54 page)
Read Shadows of Forgotten Ancestors Online
Authors: Carl Sagan,Ann Druyan
“Courage is the peculiar excellence of man,” Tacitus recorded the Roman aristocrat Claudius Civilis as saying.
14
Even if the heroic exploits of mother birds shamming a broken wing, or of elephants and chimps saving their young from predators or rushing water, or of the beta hind staring the wolf in the eye so her companions can escape—even if such examples were unknown in the time of this Claudius, didn’t he know about dogs? He was put in chains and brought before Nero. History does not record how much of the “peculiar excellence” was available to him in his hour of need.
Another ancient definition of humans, tracing back to Aristotle, is a “rational animal.”
15
This is the distinction pointed to by many of the key figures in Western philosophy. But the categorizing chimps, reasoning by analogy and transitive inference, the conversing bonobos, and the culturally innovative macaques remind us that other animals reason also; not as well as the great Western philosophers, to be sure—but the philosophers believed not in a difference of degree, but in a radical difference in kind.
“[M]an differs from irrational creatures in this, that he is master of
his actions,” was a tenet of St. Thomas Aquinas in his
Summa Theologica
. But are we “masters” of our actions always and in all circumstances? Do other animals never exhibit “mastery”? In giving, as was his practice, selected pros and cons for the propositions discussed, Aquinas—debating “whether choice is to be found in irrational animals?”—mentions a case where a stag at a crossroads seemed to choose one path by excluding the alternatives. This is rejected as evidence of choice because “choice properly belongs to the will, and not to the sensitive appetite which is all that irrational animals have. Therefore, irrational animals are not able to choose.” He also held that “irrational animals” could not command, “since they are devoid of reason.” All this may have satisfied generations of philosophers, and established a tradition that influenced Descartes, but is it not clear that Aquinas—consider his starting point of “irrational animals”—was begging the question, assuming what he was trying to prove?
16
“Actions directed towards a goal do not occur in any other animals at all,” in a like vein wrote Jakob von Uexküll, a once influential expert on animal behavior.
17
But we need only think of the chimp holding a club behind his back and searching for his rival, or collecting stones to throw at an enemy, or the female prying his fingers open and removing the stones, to realize how much in error such statements are.
For the philosopher John Dewey, what distinguishes us is memory:
With the animals, an experience perishes as it happens, and each new doing or suffering stands alone. But man lives in a world where each occurrence is charged with echoes and reminiscences of what has gone before, where each event is a reminder of other things.
18
This claim is manifestly untrue for many animals, and chimps above all live in a world “charged with echoes and reminiscences.” The cat experiencing a hot stove avoids the stove thereafter; elephants and deer soon grow wary of hunters; dogs who have been beaten cower when the rolled-up newspaper is raised; even worms, even one-celled protozoa can be taught to run a simple maze. The dominance hierarchy is a frozen memory of past coercion. How oblivious of the real life of nonhuman animals is Dewey’s attempt to define us!
Many human sexual practices have been thought to be defining.
Maybe it’s kissing: “Only mankind kisses. Only mankind has the reason, the logic, the happy faculty of being able to appreciate the charm, the beauty, the extreme pleasure, the joy, the passionate fulfilment of the kiss!” rhapsodizes a small book on the subject.
19
But chimps routinely and exuberantly kiss.
Maybe what’s special about us is our reproductive posture: “It seems plausible to consider that face-to-face copulation is basic to our species.”
20
But face-to-face copulation is common among the bonobos.
Concealed ovulation and female orgasm
21
have been thought unique to humans, but bonobos do not garishly advertise their ovulations, and female chimps, bonobos, stumptail monkeys and, probably, many other primate females have orgasms—as determined in part by equipping them with physiological sensors before they mate, in the style of an experiment by Masters and Johnson.
Maybe it’s our mode of sexual coercion: “That rape … is an exclusively human character seems to be beyond serious doubt,” opined a scientist writing on primates in 1928.
22
But rape is known among orangutans and stumptails, violent sexual coercion is a commonplace among baboons and chimps, and the doubt is serious indeed.
Maybe it’s the elaboration and duration of our sexual foreplay; in this at least some humans may lead the other primates.
23
But this is learned behavior, as the prevalence of premature ejaculation, especially among adolescent boys, and the self-taught ability of many men to postpone ejaculation make clear. In the integration of sexual acts into everyday social life humans are probably down toward the bottom of the primate list. Most human cultures demand that even socially condoned sexual behavior be carried on in private;
24
we can see something of the sort in chimp consortship, and in clandestine encounters out of sight of the dominant males.
Maybe our distinction is the traditional and striking gender-specific division of labor: The men hunt and fight; the women gather and nurture.
25
But this cannot be a defining characteristic, because chimps have a similar division of labor: Patrols, group defense, and throwing missiles are all mainly male responsibilities; caring for the young and using tools to crack open nuts are mainly female responsibilities. Also, women’s and men’s jobs are in our time becoming increasingly indistinguishable.
Our long childhood, the years between birth and puberty, is essential for our education, but it is not as long as an elephant’s; and the
progressively earlier arrival of sexual maturity in the human life cycle over the last few centuries is whittling down our childhood so that it is now only a little longer than the chimpanzees’ (who sexually mature around age ten). Play is so central to our growing up that it was once suggested
26
to call our species
Homo ludens
(“the man who plays”). But play can be seen throughout the mammalian class, especially when maturity is long delayed.
The Roman philosopher Epictetus, a former slave, held the distinguishing characteristic of humans to be personal hygiene.
27
He must have known about birds, cats, and wolves but argued that “when … we see any other animal cleaning itself, we are accustomed to speak of the act with surprise, and to add that the animal is acting like a man.” But he then complains that many men are “dirty,” “stinking,” and “foul” and do not share this “distinguishing” characteristic. Such a man is advised to “go into a desert … and smell yourself.”
Humans have been called the only animal that laughs. However, chimps smile and laugh a lot.
28
The Athenian Stranger, in Plato’s
Laws,
29
says humans are “afflicted with the inclination to weep more than any other animal.” But this inclination varies widely from culture to culture, and whimpering and crying is a fact of daily life among the chimps, children and adults alike.
30
Humans—who enslave, castrate, experiment on, and fillet other animals—have had an understandable penchant for pretending that animals do not feel pain. On whether we should grant some modicum of rights to other animals, the philosopher Jeremy Bentham stressed that the question was not how smart they are, but how much torment they can feel. Darwin was haunted by this issue:
In the agony of death a dog has been known to caress his master, and every one has heard of the dog suffering under vivisection, who licked the hand of the operator; this man, unless the operation was fully justified by an increase of our knowledge, or unless he had a heart of stone, must have felt remorse to the last hour of his life.
31
From all criteria available to us—the recognizable agony in the cries of wounded animals, for example, including those who usually utter hardly a sound
*
—this question seems moot. The limbic system in the
human brain, known to be responsible for much of the richness of our emotional life, is prominent throughout the mammals. The same drugs that alleviate suffering in humans mitigate the cries and other signs of pain in many other animals. It is unseemly of us, who often behave so unfeelingly toward other animals, to contend that only humans can suffer.
Murder, cannibalism, infanticide, territoriality, and guerilla warfare are not unique to humans, as described in preceding chapters. Ants have slaves and domesticated animals and main force warfare.
“The use of punishment in the attempt to train their young in anything other than avoidance,” writes Toshisada Nishida, “seems exclusively limited to humans … No nonprimate mammals are known to teach by discouragement.”
33
But his exception of the nonhuman primates says much. Also, many animals coerce and punish the young as part of the educational process, aiding smooth entrance into the dominance hierarchy. It’s a little like hazing and initiation rites in our species.
Humans have institutionalized marriage and advocated monogamy, at least as an ideal; but gibbons, wolves, and many species of birds practice monogamy and mate for life. The courtship dances of animals are surely a kind of marriage ceremony. The following characteristics are described as typical of human marriage:
There is some degree of mutual obligation between wife and husband. There is a right of sexual access (often but not invariably exclusive). There is an expectation that the relationship will persist through pregnancy, lactation, and childrearing. And there is some sort of legitimization of the status of the couple’s children.
34
But all of this is known in other animals, for example among the gibbons, plus primogeniture.
The nineteenth-century philosopher and theologian Ludwig Feuerbach—known for his influence on Karl Marx—proposed that the distinction of humans is recognition of ourselves as a species.
35
But many animals readily distinguish members of their own species from members of all others—for example, through olfactory cues. And humans are notable for demonizing members of their own species, declaring them less than human, to disinhibit sanctions on murder—especially during wartime.
Humans are sometimes said to be better at making class distinctions than other primates are,
36
but primate dominance hierarchies, some of them hereditary, seem to embrace a fineness of social discrimination that in some respects exceeds even our own.
We conclude that none of these sexual and social traits seem to work as defining characteristics of the human species. The behavior of other animals, especially the chimps and bonobos, renders such pretensions specious. They are just too much like us.
——
Knowledge and behavior patterns that are not hardwired into our genetic material, but rather are learned and passed on within a given group from generation to generation, are called culture. Could culture be the defining mark of humanity?
“Culture,” says a major article in
The Encyclopaedia Britannica
,
is due to an ability possessed by man alone The question of whether the difference between the mind of man and that of the lower animals is one of kind or of degree has been debated for many years, and even today [1978] reputable scientists can be found on both sides of this issue. But no one who holds the view that the difference is one of degree has adduced any evidence to show that non-human animals are capable, to any degree whatever, of a kind of behaviour that all human beings exhibit.
The author then gives three examples of behavior that he thinks characterizes humans, and concludes, “There is no reason or evidence that will lead one to believe that any animal other than man can have or be brought to any appreciation or comprehension whatever of such meanings and acts.”
37
And what are these three examples? One is “defining and prohibiting incest.” But this prohibition, at least for the father-daughter and mother-son varieties, is, as we’ve described, prevalent, indeed nearly invariable, among the primates—who have elaborate conventions to guarantee high levels of outbreeding. The taboo applies to many other animals as well. In studying Kenyan birds known as bee-eaters, the biologist Stephen Emlen carefully noted the identity and behavior of each bird; in eleven years of work he was unable to find even a single
case of incest, either between siblings or between parent and offspring. (The other two examples given in the
Britannica
article are “classifying one’s relatives and distinguishing one class from another,” which chimps do well enough—at least for mother-child and sibling kinship—and “remembering the sabbath to keep it holy,” which is an institution unknown in many
human
cultures.)
Despite the common description of the incest prohibition as a taboo—that is, learned—it seems to be, to a considerable degree, innate. It serves as a hereditary ethical proscription, evolved for good genetic reasons, and reinforced by the conventions and rules of society (although, for all that, functioning imperfectly—very imperfectly in civilized society).