What Makes Us Tick
The previous chapters took into account a wide range of phenomena and experiments that provide insights on the nature and evolution of the brain bases of human unpredictability—the creative capacity that shapes human culture.
The Biological Bases of Unpredictability
Experiments-in-nature, studies of aphasia, showed that Broca’s and Wernicke’s areas are not the brain’s language organ. Studies that took into account Parkinson disease and other instances of trauma to subcortical and cortical structures pointed to circuits linking different regions of the cortex and basal ganglia regulating motor control, including speech, and various aspects of cognitive acts, including language. Neural circuits linking prefrontal cortex and the basal ganglia played a key role in conferring the suite of cognitive acts subsumed under the cover-term, executive control. These include verbal and visual working memory, planning or suppressing a response, and the central act underlying creativity—being able to form and select an alternative course of action or concept.
These studies did not occur in isolation. Tracer studies of other species mapped out neural circuits. Microelectrode studies of brain activity in animals refined hypotheses concerning the local operations carried out in the subcortical basal ganglia, other subcortical structures, and cortex. The advent of noninvasive neuroimaging techniques that permit monitoring neural activity in living human subjects showed similar circuits linking prefrontal cortex and the basal ganglia in humans. Neuroimaging studies have clarified the local operations performed in these circuits. Ventrolateral prefrontal cortex, for example, is engaged in planning a cognitive shift, selecting words and memories in specific contexts, and a range of cognitive acts. Dorsolateral prefrontal cortex is engaged in monitoring or tracking cognitive acts as well as planning per se. The basal ganglia working with cortex constitute the brain’s sequencing and switching engine. Comparative studies suggest that the size of the human brain has enhanced its storage capacity and perhaps its computational efficiency.
Humans do not possess unique, species-specific circuits that might account for our enhanced cognitive flexibility, the root of human unpredictability and creativity. Our knowledge of how brains work and how the human brain evolved is modest, but a serendipitous experiment-in-nature identified a gene, FOXP2human, the human transcriptional factor that enhances associative learning and information transfer in the basal ganglia, supercharging the circuits that confer cognitive flexibility. Comparisons of the chimpanzee, human, Neanderthal, and Denisovan genomes have revealed other unique or modified genes that act on the human brain. The role of most of these genes is still unclear, but it is clearly the case that the genes that make us human are ones that contribute to cognitive flexibility and creativity, not genes that rigidly channel our thoughts and behavior.
Evolutionary Biology
There is a seeming contradiction earlier if you took the message of this book to be that genes don’t count. As I pointed out on the first page, we are at the start of a new era in our understanding of how our genetic endowment shapes human behavior. The “gene game” played by practitioners of evolutionary psychology diminishes insights on how genes might influence the way that we behave and think. In contrast, as I have stressed, evolutionary biology provides the basis for advancing our understanding of what aspects of our biological endowment and their evolution may account for human uniqueness. Charles Darwin introduced the methods of evolutionary biology when he attempted to account for the “transmutation” of species in 1859. He applied these methods to the study of emotion in his 1872 book, The Expression of the Emotions in Man and Animals, which attempted to take into account the role of heritable, hence genetically transmitted mechanisms. Darwin sometimes went out on a limb, as when he attributed an English child’s shrugging to her Parisian grandfather. The young girl had been raised in a proper English shrug-free environment! However, she shrugged, and Darwin implied that she had inherited an innate French tendency to shrug from her grandfather—in current terms, his shrug gene. This case notwithstanding, Darwin generally relied on the methods and principles of evolutionary biology. In discussing the facial expression of emotion, Darwin, for example, took note of the similar muscles of apes and humans, establishing a link to our primate heritage. We can “read” many of the expressions of animals, and as Michael Tomasello’s (2009) research group has shown, dogs, apes, and other features can read some of our moods.
However, it is the case that human culture plays a part in these processes. If you have ever been engaged in conversation with someone from Nepal or India, you might have noticed their heads moving from side to side to signify agreement. As David McNeill (1985) pointed out, many of the gestures by which humans communicate both referential and emotional information are “emblematic,” culturally conditioned and transmitted. One of my students got into a serious misunderstanding on a trip to India some years ago when she thought that she had forcefully signaled “no!”
Some aspects of human behavior appear to derive from “entrenched” genes. Jerry Kagan, one of the pioneers of developmental psychology, studied the biological and social bases of temperament for more than four decades. Kagan’s studies suggest that shyness has a strong genetic component (Kagan, 1981). Children of shy parents tend to be shy. Children of extroverted parents are likely to be extroverted. Kagan and his colleagues in a 1988 study showed that the physiologic reactions of shy children to low levels of task-induced stress were as much as ten times greater than outgoing, extroverted children. Kagan’s methods differ profoundly from the “mind-experiments” favored by some evolutionary psychologists. Kagan’s research group first assessed the degree to which a child was shy by observing three-year-old children’s reactions to an unusual event. Children were observed, one at a time. Each child played in a toy-filled room with her/his mother and an observer for 30 minutes or more until the child was relaxed, absorbed in play. At that point, a “spaceman” entered—a stranger dressed in a silver-colored Mylar “space-suit” with a toy helmet covering her face. The spaceman was a Harvard University graduate student. The shyest children predictably would run toward their mothers and hide behind their legs, peeking out, often in tears. In contrast, outgoing children would run toward the spaceman and sometimes even try to climb up her to remove her helmet.
A month later, the shyest and most outgoing children were monitored while they performed a simple cognitive task at increased workloads. After establishing that they regularly watched the children’s TV show Sesame Street, they first were asked to name two characters, then four, and then answer the question, “Who chased the squirrel?” Task-induced stress manifests itself at the physiologic level in heart rate, respiratory rate, galvanic skin conduction (which reflects sweating), cortisol levels, and a speech parameter that some of my early studies showed is a measure of task-induced stress. The fundamental frequency of phonation, which determines the pitch of one’s voice, has a micro-vibrato. Voice pitch always varies slightly (Lieberman, 1961). The technical term coined to describe this phenomenon is “jitter.” Jitter reflects the balance of muscular tension in the larynx and correlates with stress levels. Task-induced stress decreases jitter, and we unconsciously perceive that someone is stressed by taking account of jitter (Lieberman and Michaels, 1962).
Changes in heart rate and jitter stress measures were ten times greater for the timid, shy children than for the risk-taking, extroverted children. Stephen Suomi at NIH’s Poolesville Animal Center observed similar responses when shy monkeys encountered strangers. Since they were monkeys, it was possible to switch monkey infants and pair a shy infant with an outgoing monkey mother. When cross-fostered with outgoing monkey mothers, shy monkeys tended to remain shy. The reverse pattern held for outgoing monkey infants and shy monkey mothers, which again points to a genetic component to being shy or outgoing. There was a subtle effect of upbringing—monkey temperament was influenced by monkey mother’s temperament; Kagan estimates about 80% heritability for shyness in humans.
What Does Genetic Variation Buy?
If shyness or being outgoing have a genetic component that dates back to monkeys, why might some humans retain genes that result in their being shy and timid, while other people have retained genes that play a part in being outgoing and willing to take risks? A misadventure that befell the Poolesville monkeys points to the answer. A chain-link fence encloses the large monkey range at NIH’s primate research center. When a gap in the fence allowed monkeys to escape, timid, shy ones held back. In this instance, it paid to be shy. The adventurous extroverts who ventured out were hit by a truck as they crossed the road next to the fence. In other instances, risk-taking is appropriate. My grandparents, who left Eastern Europe at the start of the twentieth century, were not timid souls. They coped with the uncertainties of a new culture and a new language to achieve a better life for themselves and their descendants. That fortuitously turned out to be the correct choice in the “struggle for existence.” They could not have foreseen the brief Nazi reign that resulted in the murder of their timid neighbors who stayed at home. In different circumstances, different modes of behavior are advantageous.
Genetic diversity, the “feedstock” for natural selection, is generally advantageous. Famines were a recurring feature of life in India for thousands of years—they finally ended in the 1970s, when high-yield varieties of wheat and rice developed in the “green-revolution” that started in the 1940s were sown. However, one of the unwanted side-products of the green-revolution was the reduction of genetic diversity that occurred as native varieties of rice and wheat become extinct. Ecologists and agronomists have rightly pointed out that the loss of genetic diversity poses a danger. It isn’t possible to anticipate what the future may hold in store. Genetic diversity provides a hedge. The microorganisms that are responsible for plant diseases are continually evolving, and genes that no longer exist might protect food crops from a “new” threat. Global weather conditions change, and genes that would allow crops to flourish in the hot and humid conditions that may follow from global warming will not be available if every single stalk of wheat has the same high-yield genetic profile. In consequence, seed samples are being stored in the Svalbard Global Seed Vault on the remote Norwegian Island of Spitsbergen. The underground climate-controlled cavern cost about nine million dollars to construct. The yearly operating expenses are being paid by Norway and the Global Crop Diversity Trust.
Choose Your Gene
Issues concerning human morality almost always involve aggression and altruism. Here, too, evolutionary biology suggests that simplistic solutions that link behavior to genes are misleading. Jane Goodall, who over the span of 20 years observed chimpanzee life in the Gombe Stream National Park, showed that the Gombe chimpanzees have a complex fission-fusion society. Adult males and adolescent chimpanzees often roam about in small groups throughout the territorial range, while chimpanzee mothers, their infants, and young stay put. The two groups can rejoin when a new source of food is located. In this “culture,” some females have higher social ranks than others, and their social rank is passed on to their female offspring. Male chimpanzees have a more fluid social order. Males can achieve “alpha,” dominant, status by displays and bites or blows that can result in severe wounds, but within the group, violence does not extend to murder.
At the start of Goodall’s study, the chimpanzees formed a single group. However, warfare—organized murderous violence–broke out when part of the group split off from their fellow chimpanzees, yielding an IN and an OUT group. The members of this OUT group, formerly members of the inclusive group, established an adjoining territorial range until they were systematically hunted down and killed. A video provided by Chris Boehm, one of Goodall’s colleagues, shows a chimpanzee patrol on the territorial boundary. The chimpanzees had become acclimatized to videographers who accompanied them as they both performed daily routine tasks—nursing infants, termite-fishing (fishing tools were prepared by stripping branches from a small tree limb and inserting it into a termite mound), and hunting monkeys—and went on the warpath.
You can read the intent, tense faces of the file of chimpanzees in Boehm’s war video. That’s what the conflict turned into—organized murderous aggression directed toward “enemies.” As is the case for humans, friends can turn into enemies. The video shows a string of uncharacteristically quiet chimpanzees moving warily in single file as they approach the territorial boundary, attempting to find a lone “enemy” chimpanzee to mob and murder. In the instance videographed, the patrol met up with enemies masked by the dense forest. Neither they, nor their potential adversaries, could gauge each other’s strength, so they retreated. It was calculated warfare. Humans are not alone in deciding when to fight; the chimpanzee war-party retreat suggests a cognitive risks-benefits assessment.
Wrangham and Peterson (1996) documented similar instances of chimpanzee warfare and territoriality. The chimpanzee patrols and territorial claims suggest a “primitive” genetic basis, predating the evolution of hominins, for these human attributes. However, these studies of chimpanzee life also point to the presence of cognitively mediated choices—even in chimpanzees.
Alliances and favors also can provide a path to alpha-male status, through which everyone profits. Frans de Waal’s book Chimpanzee Politics: Power and Sex among Apes, published in 1982, described his observations of chimpanzees living in a captive colony at the Arnhem Zoo in the Netherlands. This book and its 2007 revised edition show that males can achieve alpha status by forming cooperative alliances and dispensing favors. De Waal traced the alliances formed by three male chimpanzees who rose to alpha status through politics—forming shifting coalitions that included females. These studies of chimpanzees show the different paths that can lead to alpha-male status—brute force or coalitions glued together by favors. Chimpanzee grooming is a sort of schmoozing practiced by both males and females—a chimpanzee removes debris from another’s fur while patting and smoothing.
Mark Foster and his colleagues documented similar acts in the state-of-nature; their 2009 paper reviewed observations made between 1989 and 2003 of the tactics used by Gombe male chimpanzees to achieve alpha status. Large males tended to rely on violent brute force. Smaller males formed coalitions to achieve alpha status and assiduously groomed other chimpanzees, both male and female. Frodo, who weighed more than 100 pounds, bit and hit his way to power, acting the role of a despot who allowed lesser chimpanzees to groom him. Frodo almost never groomed any other chimpanzee. In contrast, Wilkie, who weighed about 80 pounds, groomed his way to alpha status. Wilkie’s tactics resemble those employed by candidates to Providence’s city council—obsessive hand-shaking and offers to repave the sidewalk in front of your home. No one has isolated the genes that mediate aggression or cooperation in either chimpanzees or humans, but the data discussed earlier and in other studies of primate behavior suggest genetic bases for very different courses of action. Chimpanzees in some circumstances appear to perform “cognitive” cost-benefit assessments, choosing a course of action that is most likely to achieve their goals, reflecting some degree of cognitive flexibility.
Charles Darwin may have regretted ever coining the phrase the “struggle for existence,” which usually is interpreted to mean conflict. He stressed that he was using the phrase in a metaphorical sense and took pains to point out “complex relations” that enter into evolution that preclude simplistic assertions that a particular gene governs some aspect of behavior. Almost half of chapter III of The Origin of Species, in which Darwin attempts to explain what the struggle for existence entails, draws on examples where
plants and animals most remote in the scale of nature are bound together by a web of complex relations (Darwin, 1859, p. 73).
The complex relations discussed include ones holding between mistletoe and sundry flowers and birds, trees and cattle, insects and birds, orchards and moths. Darwin’s message was that these interactions benefit all concerned and must entail interlocking biological factors in these different species.
Morality Briefly Revisited
The abrupt shifts in moral conduct discussed earlier in the age of the Vikings and in Germany and elsewhere during the twentieth century resulted from cognitively mediated choices shared by a culture. Humans may have inherited the genetic dispositions seen in chimpanzees toward forming IN and OUT groups. And we may also have two very different genetically mediated behavioral patterns toward achieving alpha status. However, unlike chimpanzees, we can turn on a dime, shifting the membership criteria for IN and OUT groups as well as what actions are permissible in IN or toward OUT groups.
When Japan was emerging from hundreds of years of isolation in the 1930s, anyone who was not Japanese apparently was a candidate for an OUT group. Nanking, the capital of the Republic of China, was captured by the Japanese Imperial Army on December 13, 1937. Over the next six weeks, the Imperial Army murdered hundreds of thousands of Chinese. About 80,000 men, women, and children were raped. The atrocities were witnessed by a horrified German, a member of the Nazi party, who attempted to intervene. The near-instant shift in Japanese conduct at the end of World War II clearly had no genetic basis. It perhaps can be attributed to cognitive shock-treatment resulting from a rain of incendiary bombs on the wood and paper cities of Japan, the nuclear destruction of Hiroshima and Nagasaki, and the collapse of the old social order.
The human capacity to place oneself in the place of another (the technical term is “theory of mind”) is a necessary, but not a sufficient, condition for not doing harm. Children at first lack this conceptual capacity; it gradually develops, as is the case for other aspects of cognition. A primitive theory of mind is often equated with the “mirror-test,” in which a chimpanzee can recognize that she is viewing herself in a mirror, but apes act in a manner that they themselves would find unacceptable. The Gombe chimpanzee video records include a hunting party sharing part of a kill. A screaming live monkey is the tidbit being passed from ape to ape as they each take a bite. Humans often act in worse manner.
Our human ability to place oneself in the place of another can enhance brutality, inflicting degrading torture that no ape can conceive of, as well as acts in accord with the “Golden Rule.” It took a long time for the Golden Rule to be codified. In the Hebrew Bible, which was written over thousands of years, the code of Jewish conduct changed from the celebration of King David’s wars of extermination (whether they actually occurred or not) to the teachings of Hillel, who lived at about the same time as the historical Jesus. Hillel summed up the meaning of Torah, the Hebrew bible, as
that which is hateful to you, do not do to your fellow. That is the whole Torah; the rest is the explanation; go and learn.
The same injunction, rephrased in the gospel of Matthew, is the usual form of the Golden Rule:
Do unto others as you would have them do unto you.
It took a long time for “enlightened” WEIRDO cultures to act on the Golden Rule. In 1745, after the battle of Culloden, three Scottish rebels were first hanged by the neck at the Tower of London. After 14 minutes, they were cut down, still alive, and disemboweled. Their bodies were then quartered. Thirty-one years later, King George’s government, anticipating the execution of Benjamin Franklin, Thomas Jefferson, George Washington, and their fellow rebels modified the schedule of punishment, eliminating disembowelment. However, whether this change reflected a change in moral attitude, or efficiency, it was never carried out, because the rebels morphed into the statesmen of the United States of America. The Golden Rule still doesn’t seem to characterize human conduct.
Is It a Boy or Girl on the Phone?
Something as disarmingly simple as deciding whether it is a small boy or girl speaking to you on the telephone illustrates the intersection of genetic endowment and culture. Girls’ names usually signal that they are a girl, but that isn’t always the case. But when you hear a girl speaking on the telephone, you usually can tell that a girl talking to you, apart from what she might be talking about. That can be the case, even when she is five years old. However, when one of our youngest son’s friends phoned, I was certain when I answered the phone that it was a girl, which turned out to be wrong. The acoustic signal somehow had indicated that it was a girl. I was then working with Edmund S. Crelin at Yale University, whose specialty was human anatomical development. When I mentioned this odd misidentification in passing to Ed, he, too, was puzzled, because there are no anatomical differences at age five that would cause a girl’s voice to have acoustic characteristics that are different from a boy’s. Why did I think that a young girl was on the phone?
Jacquie Sachs, who was a member of the faculty of the University of Connecticut’s Department of Speech; Donna Erikson, one of my graduate students; and I decided to study a group of children and acoustically analyze their speech. My boy/girl error suggested that the acoustic distinctions might reflect gender rather than biological sex, and that supposition was confirmed. We recorded 30 five-year-old boys and girls. The children were recorded as they chattered about what they were going to do that day and as they named pictures of animals. When short segments of their speech were presented to a panel of adult listeners, the boys were all identified as boys, but three girls were identified as boys. The girls were said to be tomboys by their parents. My son’s friend wasn’t among our subjects.
Acoustic analysis showed that there was no systematic difference between the boys’ and girls’ fundamental frequencies of phonation—the acoustic determinant of pitch. As chapter 2 pointed out, the pitch of a person’s voice is our perceptual response to the average fundamental frequency of phonation (F0), the rate at which the vocal cords of the larynx open and close. The similar range of voice pitch for the boys and girls wasn’t surprising. It is common knowledge that boys’ voices don’t change until puberty, when the male larynx becomes larger, yielding lower-pitched voices. What then signaled that it was a boy or girl talking, or rather a child who wanted to be perceived as a boy or girl? Acoustic analysis revealed different average formant frequencies for “boy” or “girl” voices. Boy vowels had lower formant frequencies than the same girl vowels. This difference also was unexpected because at age five there didn’t seem to be a systematic difference in the length of boys’ and girls’ supralaryngeal vocal tracts (SVTs)—the distance between their lips and larynx (since confirmed by D. Lieberman and McCarthy, 1999, and D. Lieberman et al., 2001). The length of the SVT, as you saw in chapter 2, determines the absolute value of vowel formant frequencies. Longer SVTs produce lower formant frequencies.
Observations of the children’s lips as they talked solved the mystery. Boys produced a male vowel “dialect” by slightly “rounding” their lips as they talked, protruding and closing them ever so slightly. These lip maneuvers lowered their vowel formant frequencies. In contrast, the girls’ female vowel dialect resulted from children retracting their lips, smiling ever so slightly, which raised their formant frequencies. In effect, boys modify their vowels to “sound” bigger, girls “smaller.” Our son’s friend on the telephone, who had three sisters, apparently had picked up the wrong dialect. Subsequent studies have replicated these gender-specific gestures for children living in the United States. It is not clear whether this is a “universal” aspect of human behavior because systematic studies of children living in other cultures have yet to be done. Formant frequencies provide a better cue than pitch for conveying gender because there is a great deal of overlap between the pitch ranges of men and women. Moreover, it is almost impossible to systematically raise or lower your pitch during normal conversations.
The perceptual difference between the American-English male and female speech dialects might best be described in musical terms as timbre. The dialects serve to signal gender. Why did the children act in this manner? Human conduct suggests that it is one of the many ways that biology and culture intersect. Male and female birds generally have different plumage. Size and morphology differentiates male from female chimpanzees, gorillas, and orangutans, but humans as a species have less secondary sexual dimorphism than apes. In very different human cultures, clothing and manner instead serve to signal gender, usually, but not always coincident with biological sex. In societies where males and females have specified tasks that are necessary for survival, such as in traditional Greenland Inuit society, girls will affect male clothes, act like boys, and carry out a male-specified task such as hunting seals in families that have daughters but no sons, until they are about to marry. An anthropologist who lived with an Inuit family once related how she was startled when she was invited to the marriage of the girl she had thought was a boy up to a week before the event.
Boy versus girl voice qualities reflect a “primitive” biological, genetic reality. Adult males as a group have longer vocal tracts and are bigger than adult females. The five-year-old children were modeling their behavior on these archetypes, but they didn’t have to—no one was instructing them to do so, and there was an element of choice involved. The “tomboys” didn’t adopt the female register.
I used the term “primitive” in its evolutionary sense—a characteristic that a species shares with ancestral species. In this instance our voice is signaling how big we are, in a manner similar to the actions of monkeys, deer, and other species. Almost 30 years elapsed before this possibility suggested itself. A series of studies by W. Tecumseh Fitch, before he became preoccupied with Universal Grammar and recursion, shows that many animals estimate how big a conspecific is, by taking account of the absolute value of formant frequencies (Fitch, 2010). Male deer pull their larynx down as they vocalize to make themselves sound bigger to other deer, (Fitch, 2000). McElligott et al. (2006) writing in the Journal of Zoology, describe male deer calls during mating season as “groans” that are pleasing to does. I don’t know of any human courtship ritual that involves men groaning to attract a mate, but the formant-frequency gender specifying effects that marked five-year-olds in Storrs, Connecticut, in 1972 and other young children (mostly WEIRDO kids, owing to where our study has been replicated) seem to have antecedents in the behavior of other species.
Culture as an Agent of Genetic Change
It should be clear that it is inherently impossible to completely partition the contributions of culture and genes to behavior. Culture is the agent that shapes human ecosystems and hence intersects with biology at the genetic and epigenetic level. Epigenetics, the study of instances in which the DNA sequences that constitute the genetic code do not change but the expression of genes changes, also points to cultural-genetic interaction. Studies of mammalian species running the gamut from rodents to humans show that environmental factors can have epigenetic effects, changing the expression of genes. Rat mothers, for example, clean and groom their pups after birth, and some rats groom their pups to a much greater extent than other rat mothers. The mothers’ licking turns out to trigger the pup’s hippocampus, which, in turn, releases a sequence of hormones that change the expression of genes. Pups that are groomed to a greater extent are healthier, grow faster, and are “better” rats than those born to rat mothers who groom their pups to a lesser extent (Zhang et al., 2010). Marcus Pembry, who was a member of the research team that studied the KE family and led to the discovery of the FOXP2 transcriptional factor, is the lead author of a study that points to epigenetic effects in humans. Pembry and his colleagues studied the grandsons of Swedish men who experienced famines as children during the closing years of the nineteenth century. Sweden then was a poor country that had little in the way of a social safety net, accounting for the thousands of Swedes who migrated to the United States. The grandsons of Swedish men who grew up during these nineteenth-century famines are less likely to die of cardiovascular diseases, but are more susceptible to diabetes. The granddaughters of Swedish women whose mothers experienced famine while bearing them lived shorter lives. Behavioral data also suggest epigenetic effects on intellectual development. Jerry Kagan found that impoverished, narrow environmental stimulation during the first year of life impeded a child’s intellectual development, but the delays could be removed by a richer, stimulating, environment during the second year of life (Kagan, 1981).
Current research surprisingly shows that the “social” environment can even have a direct effect at the genetic level, such as the release of transcriptional factor Foxp2. Zebra finches, as noted earlier, are the birds of choice for research on the behavioral effects of the Foxp2 transcriptional factor. Zebra finches learn new songs each year, and the avian form of Foxp2 peaks in the birds’ circuit to area X of the bird brain (Brainard and Doupe, 2000; Doupe et al., 2005). This circuit is homologous with the cortical-basal ganglia neural circuits implicated in associative learning in mammals. Surprisingly, Foxp2 is at a higher level when a male bird is actually singing to a potential mate, than when the he is alone, practicing his songs (Teramatsu and White, 2006).
Culture, Language, and Thought
Finally, though biology and hence genetics determines baseline human cognitive capacities, there are intimate, complex relationships that hold between biology, culture, language, and thought. Biology sets limits on thought, but culture changes biology, language transmits culture, and culture influences language and thought. Paradoxically, current research that is unraveling these processes started with the supposition that language constrains thought.
In the middle years of the twentieth century, the American linguists Edward Sapir and Benjamin Whorf claimed that language shaped and fixed your worldview. In the extreme version of their theory, “Linguistic Relativity,” a person’s language placed absolute* limits on his or her conceptual framework. The roots of the Sapir-Whorf hypothesis can be traced back to the early years of the nineteenth century. Wilhelm von Humboldt in 1835 took an even more extreme view of the effects of language on thought. Humboldt, in his opus On Language: The Diversity of Human Language-Structure and Its Influence on the Mental Development of Mankind, set forth the premise that language determines the intellectual attainments of a culture. To Humboldt, language and cognition were indivisible:
Language is the formative organ of thought. . . . Thought and language are therefore one and inseparable from one another (Humboldt [1835] 1988, p. 46).
Humboldt had some peculiar views on how language affects thought. Humboldt was taken with the notion that inflected languages, such as Latin and German, that modify a word to indicate whether a person or thing is the subject or object of a verb, are superior instruments for thought than uninflected languages that instead use word order for that end. In Humboldt’s day, Sanskrit was thought to be the end point of inflected languages. Sanskrit to Humboldt therefore marked minds capable of the greatest intellectual achievements. German, Humboldt’s native language, was pretty close. In contrast, Humboldt asserted that Chinese, at the other end of the inflected-uninflected scale, which relies on word order to convey who is doing something to whom or what, was an inferior vehicle of thought. Chinese-speakers to Humboldt therefore had inferior cognitive abilities—a claim that reflects Wilhelm von Humboldt’s profound ignorance of the achievements of Chinese civilization. Wilhelm von Humboldt, unlike his brother, Alexander von Humboldt, the early nineteenth-century explorer and naturalist, never lived or traveled outside of Western Europe.
The Sapir-Whorf hypothesis has been hotly disputed. Many of the phenomena cited to support the Sapir-Whorf hypothesis did not hold when reexamined. Eskimos (Inuits) were supposed to be able to perceive finer distinctions between different types of snow than monolingual speakers of English because the Inuit language had many words that described different types of snow, but that wasn’t the case (Pullum, 1991). Whether you have many words to describe snow conditions or a few doesn’t really affect the fact that virtually anyone can perceive that the snow on the ground is soft or hard. However, having words that convey these distinctions does make it simpler to communicate snow conditions. English-speaking cross-country skiers have to take into account snow conditions and therefore coined and used “new” compound words such as “blue-wax-snow,” “green-wax-snow,” “red-wax-snow” to communicate distinctions in snow that are of interest to skiers. A culture’s needs are reflected in language. Linguistic relativity was declared dead after study after study refuted Whorf’s claims, but the focus of these studies was simplistic. It isn’t simply the case that thought is constrained by language; language reflects the needs of a culture and also affects the way that the members of that culture view the world.
Language as a Tool
Daniel Everett’s 2005 report on the language and culture of the Piraha people, who live in near isolation in Brazil’s vast Amazonian region, was a bombshell in the hermetic world of linguistic scholarship. The process of recursion, which to Noam Chomsky, Marc Hauser, Tecumseh Fitch, and other like-minded linguists was supposed to be the feature that singles out language from all other aspects of behavior, doesn’t seem to exist in the Piraha’s language. The Piraha don’t have a written language, which isn’t strange when you reflect on the fact that until recently, say 10,000 years ago, that was the case for everyone. But even illiterate people when they speak produce sentences, and Piraha sentences never include relative clauses, embedded clauses of any kind, or even the conjoined sentences that four-year-old children speaking other languages produce.
Everett showed that Piraha uses only simple sentences; recursion does not exist in the Piraha language. The reaction to Everett’s 2005 Current Anthropology paper and his 2008 book ranged from some dedicated adherents of Noam Chomsky calling Everett a liar, which is not usual in scholarly discourse, to Chomsky’s (2012a, p. 1) finessing the problem by proposing that the “range” R of recursion could be “null,” thereby sweeping the proposition that recursion is the defining property of human language under the carpet.
But the focus of Everett’s work is not on Noam Chomsky or recursion. Everett’s 2012 book Language: The Cultural Tool makes it clear that he views language as a tool that is crafted to meet the needs and values of a culture. The Piraha comfortably live in a very relaxed manner on the bounty of the river and fertile land. Day, night, moonlight, rainfall, and the level of water of the river set the rhythm of life. As Everett, who lived with the Piraha for a total of 86 months, points out:
The Piraha tend to talk almost exclusively about the here and now. They do not celebrate birthdays or anniversaries. They do however, recognize the passage of time through wet and dry seasons, and use the full moon as a simple calendar.
In consequence, they have 12 words that refer to time: ahoapio’ signifies another day; ahoa’i night; a’hoakohosihio, early morning; pi’i, now; and words for during the day, noon, sunset, full moon. A month is roughly “moon.” There is no word for a week. A year is “water,” referring to a cycle of high and low water in the river. Two words, pila’iso and piibigaiso, signify low water or high water. Beyond that, the Piraha don’t seem to concern themselves with time, and their language doesn’t have tense markers that convey present and past actions.
The Piraha language also seems odd to me and probably to you in that it has no explicit color terms or numbers. The color of something is simply described as the color of X, where X is another item in immediate view or in shared knowledge. Everett attempted to teach Piraha young and old to count—he failed. In light of the fact that pigeons can be taught to count up to nine items (Scarf et al., 2011), it is unlikely that any mental deficiency is responsible for the Piraha being arithmetically challenged. Nor is it likely that they lack the “number faculty” proposed by Chomsky (1988, p. 168). According to Chomsky, children do not learn to add numbers; innate knowledge of arithmetic is also preloaded into our brains. However, the Piraha language meets their needs. There is no genetic basis for these features of the Piraha language. Children abducted by other tribes have no difficulty learning other languages, including Brazilian Portuguese. Piraha gene frequencies, moreover, include those of other groups, owing to their custom of offering daughters or wives to visiting males.
The Piraha language reflects the needs of their culture and constrains their view of life. The absence of past, present, and future tense markers in their language reflects their living in and being concerned with the present. Everett initially came into the world of the Piraha as a missionary to bring the word of Jesus Christ to them. He learned their language so that he could translate and bring the good news of the Bible to them. The conceptual constraints of Piraha culture, manifested in their language, were evident when he completed his translation of the Gospel of John. The reaction of the Piraha when he read it aloud was to ask where and when he had met John. On being told that he had never met John, they had no further interest in the teachings of John. Everett had not personally heard John telling his story, and the story therefore could not be true. The Piraha have no sense or record of history beyond the lifespan of a living observer; events that have not been witnessed by a living person have no standing. Piraha bards reciting tales of the distant past do not exist.
Language to Everett is the mirror of culture; the concepts coded in a language are tools that play a useful role in a culture. Everett’s books are delightfully jargon-free, so you can best appreciate the complexities that hold between culture, language, and thought by reading them.
The Genes That Count
The field of psychology tends to continuously fall for comprehensive theories—Freud, Skinner, Jung—that don’t pan out empirically. That also is the case for Chomskian linguistics and the school of evolutionary psychology that relies so heavily upon it. We supposedly have an innate moral organ transmitted by a gene or genes that shape a “Universal Moral Grammar” similar to the Universal Grammar instantiated in Chomsky’s Faculty of Language. Evolutionary psychology proposes similar answers for other human attributes. Art, a human quality whose qualities are perhaps even more elusive, supposedly results from another module that yields our “art instinct.”
When these theories are not patently absurd, such as an art-instinct theory that predicts that everyone on earth prefers images of a grassy plain with a few trees and water to all other scenes, they are just-so stories, crafted so as to be impossible to falsify and hence predict nothing. Instead, virtually everything that characterizes the way that we live is the product of human culture, transmitted from one generation to the next through the medium of language. But the form of one’s language is culturally transmitted, again through the medium of language. And, in turn, culture shapes the human ecosystem and can lead to genetic evolution.
We are at the starting point, not the end, of the quest to understand how the human brain works and was shaped. However, what is clear is that we are not ruled by genes that were fixed in earlier stages of human evolution, or genes inherited from our primate ancestors, or invented genes that never were. It is becoming apparent that the genes setting us apart from our primate cousins act to enhance our cognitive capabilities and confer our cognitive flexibility—the engine of human creativity that allows us to shape our destiny. We possess the ability to change the manner in which we act toward each other and how we view the world around us. It is precisely because we are so unpredictable that humans are unique.
We are the unpredictable species.