LANGUAGE, A NURTURE OF NATUREEXPRESSIONSThe movements of expression in the face and body, whatever their origins may have been, are in themselves of much importance for our welfare. -Charles R. Darwin (1872)

Last night I went home and just tried an experiment. I turned on the television but turned off the sound and tried to see how much I could understand in communication without words. The news reporters had fairly deadpan expressions as they attempted to inform their audience about floods, crimes, etc. Ahem. Others, like talk show hosts were very expressive, almost like caricatures of people speaking. Their eyes opened too wide, they grinned too wide. If they had been observed outside of that setting, they might have been considered deranged.

The subtle communication that we are capable of through our expressions is quite amazing. We can tell the general emotional state of someone just by observing all but the most poker-faced individuals. This is the kind of experiment that I do almost every day as a teacher. It is not hard to tell when students are interested and engaged with the topic. It is also very obvious when they are not (even when their heads don’t fall onto their desktops). Their glassy eyes, distant stares, and great expressive yawns are dead giveaways that I have lost them.

I did that experiment as a consequence of reading a republication of Darwin’s The Expression of the Emotions in Man and Animals (1872). [For perspective, Darwin published The Origin in 1859 and The Descent of Man in 1871. He died in 1882.] In this book, Darwin attempted to show that human expression is a trait and further demonstrates our connection with the rest of life, particularly the other animals. The arguments begin by considering the expressions of emotions in animals such as dogs and cats. All I need to do is look at Figure 6-73, illustrations from Darwin’s expressions book, and I know the emotional states of the dogs that are depicted. Darwin called expressions such as these, “the language of the emotions.”

FIGURE 6-72. Expressions of interest, wonder, and caution (the bird).

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Chimpanzees and other primates have an array of elaborate behaviors that include a battery of expressions of emotions. Darwin considered their expressions, especially their expressions of anger, in a chapter called “Special Expressions of Animals”. Darwin described the response of the chimpanzee (illustrated in Figure 6-74) in this way:

The accompanying drawing represents a chimpanzee made sulky by an orange having been offered him, and then taken away. A similar protrusion or pouting of the lips, though to a much slighter degree, may be seen in sulky children.

FIGURE 6-73. Illustrations from Darwin’s Expressions book. It is quite easy to discern the emotional states of the dogs.

FIGURE 6-74. A chimpanzee disappointed and sulky (from Darwin’s Expressions).

Darwin then devoted the rest of the book to human expressions. He described observations of expressions of suffering, hatred, disgust, surprise, etc. In all, he discussed the expression of nearly 40 emotional states and expressions (generally facial expressions) that accompany those states.

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THE THIRD CHIMPANZEEThe chimpanzees, not the gorilla, are our closest relatives. Put another way, the chimpanzees’ closest relative is not the gorilla but humans. -Jared Diamond (1992)

Not only are chimpanzees expressive in ways that are similar to humans, but they appear to be our nearest living relatives. Molecular Biology has provided an array of powerful tools with which to study life. Evolutionary biology predicts that those species that are more closely related would share the greatest amount of DNA. That is indeed true of the human and the chimpanzee. In fact, Chimpanzees share 99% of their DNA with humans. That is the largest overlap in DNA that we have with any other species on earth. The interpretation is that Chimpanzees are a sibling species with whom we share a common ancestor. Without knowing of DNA and its importance, Darwin assumed as much because details of anatomy and physiology suggested the same things.

Faced with this evidence and an array of fossils, biologists, anthropologists, and psychologists have struggled with the question of what makes humans unique. Or, what are the characteristics that define our species. It seems that the torso of humans is quite similar to that of the apes. However, both ends (pelvis down and neck up) exhibit considerable change from the typical ape body plan.

Anatomically, the most obvious difference is that humans have a shallow pelvis and walk upright. Although the apes can do this for a short distance, they tire easily. Mostly, this is because the Gluteus maximus (the large muscles that form the curvature of our bottoms) are relatively small and attached to their elongate pelvis such that walking upright is mechanically difficult. Thus, much of their locomotion on the ground is by brachiation (knuckle walking).

An upright stride seems to be one of the first things that developed after the hominid line (our line) separated from the apes. An astonishing discovery by Mary Leaky at Laetoli in Kenya was three sets of footprints that had been made in volcanic ash after it had been wet by drizzle. Because volcanic material is relatively easy to date, she found that the tracks had been made about 3.6-3.8 million years ago. The astonishing part of the discovery is that the stride (though relatively small) was made by an upright, human-like gait. Fossils suggest the same thing. Very early, our line evolved a fairly human-like pelvis and legs. Therefore, the upright gait would appear to be the most fundamentally different characteristic that the hominid line possesses.

Obviously, there are other anatomical differences, but they seem to be there by degree. That is, we have less hair, a relatively larger head, smaller face, and smaller teeth (particularly canines) than the chimpanzees. However, as a fetus, a developing chimp looks just like us. This difference can be seen even in monkeys. Consider adult and baby baboons. The adult has an elongate, dog-like muzzle while the baby has a flattened, almost human face. These types of observations confirm the theory that in our lineage, development became arrested at more fetal stages. For example, the skulls of fetal chimps and humans are not very different. However, during growth and development, the face of the adult chimpanzee becomes much more elongate than the human face which deviates little from the fetal plan. In addition, humans became mature (stopped developing) before adult ape hair patterns, dentition, and elongate facial features appeared. We became a Peter Pan species, the chimpanzee that never grew up.

Still, most of the anatomical features seem to be characteristic of our whole line from the australopithecines to humans. The form of the body was ours, but the brain still

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remained like that of any other chimpanzee until a rapid increase in brain size began with the members of our own genus, Homo. What could have fostered that change? The opposable thumb? The upright stance? I suspect that they may have been part of the story, but only part of it. I suspect that our culture and technology followed another great set of changes that led to our increased ability to communicate. Those changes that involved facial expressions and the vocal apparatus in turn led to more sophisticated control by the brain.

BIOLOGY OF LANGUAGEThe language that each person acquires is a rich and complex construction hopelessly underdetermined by the fragmentary evidence available to the child. -Noam Chomsky

A large battery of facial muscles controls facial expressions, and they emerge through the interactions of the muscles. A human face has muscles that control the shape of the mouth and eyes as well as how the nostrils flare and the fore head wrinkles. Figure 6-75 shows an illustration of facial musculature that Darwin included in his book. Note the concentration of muscles around the eyes and mouth.

FIGURE 6-75. Facial musculature from an illustration in Darwin’s expressions book.

Also, we are a noisy, communicating species. Although chimpanzees can make sounds, their range of sounds is limited. This is mainly due to the placement of the larynx, the organ that lies on top of the trachea (wind pipe) and contains the vocal cords. Humans have a trachea that lies well down in the throat. The resonating chamber in which the vibrating vocal cords can produce sound is, therefore, quite large. Chimpanzees, on the other hand, have their larynx at the back of the mouth, way up in their throats. So, their range of potential sound is quite limited.

The placement of our larynx does not come without its cost. Chimps and other apes can drink and breathe at the same time, something that I would not recommend anyone who is reading this to try. It seems that vocalization is so important to our species that

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we evolved a mechanism that puts us at risk of choking every time we sit down to a meal. That and our puny teeth require that we soften most of our food by cooking it.

The tradeoff is well worth it. We can make a rich array of sound filled with subtleties and majesty when we sing (as I had the pleasure of doing recently when I sang R. V. Williams’ Dona Nobis Pacem), or just rattle away in empty conversation. We are a communicating species.

Noam Chomsky and others in the study of language, see evidence that general linguistic rules are universal. That is, there are no mute groups of humans and all human languages seem to possess fundamental similarities. Also, evidence suggests that children are born with the ability to learn a language, not a particular language. Infants begin by babbling and then acquire rules to the language that they hear such that they can construct novel sentences out of words that they have learned. The particular steps in the acquisition of language are objects of current study. Steven Pinker points out that children in their 3rd year who are acquiring English learn: Verbs end in –s in some sentences and are bare-ended in others. To search for grammatical causes of this situation. To make verbs agree in tense, aspect, number, and person.They do this without being told or drilled or tested. Also, this applies to 3 year olds who are learning English regardless of whether their parents speak English, as a first or second language.

If fundamental rules of language acquisition are instinctive, then they must be controlled by particular parts of the brain. These areas would have to work in concert with portions of the brain that control the motor coordination of the tongue, larynx, and lips as well as regions in that store vocabulary and memory. Stroke victims show that areas such as Broca’s area and the region where the parietal, occipital and temporal lobes come together are all important in language1. Damage to one or more of those areas leave the victim, who could once communicate quite well, impaired in speech or communicating ability. There is further evidence that certain speech/linguistic disorders occur in families and are inherited like any other genetic trait.

This view of language is not entirely comfortable for many who believe that language is cultural and is nurtured by the culture in which it is embedded. By culture, I mean the collection of traits or characteristics of a group of people. That is, in a cultural view, language is learned from others. In essence, this is the question about the differences between mind and body, sometimes called nature versus nurture.

The study of linguistics shows that the nature-nurture debate is an empty dichotomy. Genetics (nature) provides for the anatomy and physiology necessary for communication while culture provides for the particular linguistic rules and vocabulary. This is all built upon and supported by an impressive array of expressions.

Although humans have developed impressive abilities in communication, we are not entirely alone. Other apes, particularly chimpanzees, have been taught to communicate with humans. Although chimps and gorillas do not have the anatomy that allows them to vocalize human speech, they have learned sign languages or other symbolic languages. Some like the chimpanzee called Washoe can do much more than mimic sentences and can put words together in novel ways using the American Sign Language.

1 See Evidence and Einstein’s Brain for more information about the major regions of the human brain.

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TIME MACHINE2

Man not only uses inarticulate cries, gestures and expressions, but has invented articulate language; if, indeed, the word invented can be applied to a process, completed by innumerable steps, half-consciously made. -Charles Darwin (1872)

Does the ability of chimpanzees to communicate with us by a human language diminish us in any way? Of course not. Like most of our differences, we differ from the chimpanzees by degrees. We have converted our language to symbols that can be read and understood by others. This invention, written language, is without doubt the greatest achievement of our species. Written language allows me to speak to you now and forty years from now.

In a way, written language is a time machine. I can read the words of Darwin and discuss them with the words of Chomsky in my mind. In fact, in that way, I had a discussion with my father last week as I read a brief letter that he wrote before he died in1986.

We read and then write to contribute to and participate in the great discussion of humanity. That is why I stress writing so much in my courses. Of course, all writing is not good, most of it is trivial, some is downright evil. But as a species, we have nurtured our nature to preserve some of the most moving and substantial thoughts created by humanity in the form of written language.

1998, revised 2003References:Cartmill, Matt. 1998. The Gift of Gab. Discover. 19(11): 56-64.Darwin, Charles. 1998 (1872). The Expression of the Emotions In man and Animals. 3rd

edition with an Introduction, Afterword and Commentaries by Paul Ekman. Oxford University Press. Oxford.

Diamond, Jared. 1992. The Third Chimpanzee. HarperCollins. New York.Fouts, Roger. 1997. Next of Kin, What Chimpanzees Have Taught Me About Who We

Are. William Morrow and Co., Inc. New York.Johanson, Donald and Maitland Edy. 1981. Lucy, The Beginnings of Humankind. Warner

Books. New York.Johanson, Donald, Lenora Johanson, and Blake Edgar. 1994. Ancestors, In Search of

Human Origins. Villard Books. New York.Kurten, Bjorn. 1993. Our Earliest Ancestors. Trans. Erik J. Friis. Columbia University

Press. New York.Lumsden, Charles J. and Edward O. Wilson. 1983. Promethean Fire, Reflections on the

Origin of Mind. Harvard University press.Mayr, Ernst. 1997. This is Biology, The Science of the Living World. The Belknap Press

of the Harvard University Press. Cambridge, Mass.Pinker, Steven. 1994. The Language Instinct, How the Mind Creates Language.

HarperPerennial. New York.

2 I expand on human evolution and human communication in Our Great Leap Forward.

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Questions to Think About

1. What was is the focus of Darwin’s “Expressions” book?

2. Who is Washoe? Why is she of interest to scientists?

3. What allows the human face to be so expressive?

4. What evidences do evolutionary biologists use to conclude that chimpanzees are our nearest living relatives?

5. Why are humans able to stand upright?

6. What evidence suggests that the Hominid line has stood upright for at least 4 million years?

7. Why can a chimpanzee drink and breathe at the same time?

8. What evidence suggests that language is instinctive?

9. How does culture influence language?

10.How does written language function as a time machine?

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