Reading Charles Darwin’s The Expression of the Emotions in Man and Animals

Charles Darwin's Expression of the Emotions in Man and Animals (Penguin Classics), 1890 second edition, edited by Professor Joe Cain and Dr Sharon Messenger ISBN 9780141439440

Published in 1872, The Expression of the Emotions in Man and Animals was a book at the very heart of Darwin’s research interests – a central pillar of his ‘human’ series. This book engaged some of the hardest questions in the evolution debate, and it showed the ever-cautious Darwin at his boldest. If Darwin had one goal with Expression, it was to demonstrate the power of his theories for explaining the origin of our most cherished human qualities: morality and intellect. As Darwin explained,

“He who admits, on general grounds, that the structure and habits of all animals have been gradually evolved, will look at the whole subject of Expression in a new and interesting light.” (Darwin 1872: 12)

This Penguin Classics edition reprints the 1890 “second” edition of Expression. This is essentially the same work that first appeared in the 1872 first edition but with minor amendments and additions by Charles’ son Francis from notes left by his father.

Human Evolution After The Origin of Species

In the rush to complete On the Origin of Species (1859) Darwin made some strategic decisions. He had enough on his hands presenting the general case for evolution and proposing natural selection as its chief mechanism. In his haste, and cautious not to damage a carefully cultivated reputation for cautious empiricism, Darwin deliberately dropped several key topics. These, he thought, would simply be too distracting. The original origin of life was one subject to defer. Little firm evidence existed on the subject, and empty metaphysical hypothesising seemed the order of the day. “Speculation,” was the criticism Darwin least wanted attached to his name.

Another topic Darwin avoided was human evolution. His only comment in the Origin was to hint at the possibilities.

“In the distant future I see open field for far more important researches. … Light will be thrown on the origin of man and his history.” (Darwin 1859: 488)

This deferral was deliberate. Darwin was a clever researcher and an experienced writer. Writing privately, he was blunt. “I think I shall avoid the whole subject,” Darwin told fellow naturalist Alfred Russel Wallace (1823-1913), as it was “so surrounded with prejudices; though I fully admit it is the highest and most interesting problem for the naturalist.” (Darwin to Alfred Russel Wallace, 1857)

Though Darwin made strategic cuts to the Origin, he also had a master plan. More than anything, Darwin wanted readers of the Origin to appreciate the organisation and clockwork in all the pain, misery, and suffering that came from the struggle for existence. The underlying order and purpose made it seem justified.

“There is a grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.” (Darwin 1859: 489-490)

Perhaps, these laws were part of a designer’s plan; perhaps there was no design after all. Darwin wanted to avoid that argument – another strategic decision. Suffice it to write in a way compatible with both visions. Darwin kept his focus squarely on uncovering the laws themselves. In this way, he stood ready to measure his success on several levels. Perhaps evolution would be accepted. Perhaps even his theory of natural selection would be agreed. At the very least, he hoped, critics would accept the need for scientists to focus on laws of nature and to respect his methods for uncovering them.

No one let Darwin off so lightly, however. While specialist scientists debated technical points (e.g., the operation of natural selection, his theory of inheritance, the importance of true randomness in nature, and his speculations about how different groups might be related one to another), the vast majority of commentary about the Origin focused on the questions Darwin intentionally ignored: the origin of life, the origin of humans, and the role of God. As the Prime Minister Benjamin Disraeli (1804-1881) aptly summarised the discussion in 1864: was man an ape or angel?

Regarding human origins, popular myth today leads most people to think this question has only two answers: either Divine creation or evolution. However, in the 1860s (as is also true today), people responded with a wide range of answers. After the Origin first appeared in 1859, commentary about human origins focused on several main themes. Those many answers made the subject quite dynamic, indeed.


In the early 1860s nothing in popular science captured the public imagination more than the gorilla. Museums scrambled for specimens. Travelling collectors offered glimpses in sensational public lectures. Paul du Chaillu (1835-1903), a French-American explorer who travelled through equatorial West Africa in the 1850-60s, found fame in early 1861 when he visited Britain on one such lecture tour. Surrounded by gorilla skins, skeletons, and skulls, he told audiences fantastic stories of exploration, peril, and adventure in search of gorillas and other wonders in a region few Europeans had managed to safely navigate. Du Chaillu’s timing in 1861 was incredibly lucky. With discussions about the Origin raging, his tour became one of the season’s most exciting events. Satirists from newspapers and magazines made great use of the gorilla that year.

Richard Owen (1804-1892) had already used the gorilla to interpret human anatomy. One of Britain’s leading anatomists, Owen cared for collections at the Royal College of Surgeons (London) before becoming superintendent of the natural history department of the British Museum in 1856. Owen played a critical role in securing that department’s new facility in South Kensington (now the Natural History Museum), which opened in 1881. He also was an important scientific advisor to government. Owen produced important research on most vertebrate groups, from dinosaurs (a group he named) to mammals; from fossil fishes to extinct birds, such as New Zealand’s moa. He opposed evolution for both technical and philosophical reasons.

In 1857, Owen used brain anatomy to argue for the uniqueness of humans. Some features, he said, were “peculiar to the genus Homo”. One example was the hippocampus minor, a small part of the hind brain whose function was not known, but which Owen suggested was connected to humanity’s “peculiar mental powers”. Owen said he could find nothing like it – no homology – in the brains of other creatures. He thought this difference was of fundamental importance. Together with other special features of human anatomy, it justified placing humans in a distinctly separate sub-class of mammals, essentially separating us from zoological study. This was an extraordinary proposal. When du Chaillu offered his specimens for sale, Owen made sure the British Museum purchased them, regardless of the price. He quickly studied this fresh material, and in March 1861 announced confirmation of his claims. The gorilla had no hippocampus minor; humans remained different in kind from the apes.

Thomas Henry Huxley (1825-1895), biologist and science educationalist, is famously remembered as Darwin’s bulldog – the secondary figure who did the hard work of Darwin’s public defence. Huxley could just as easily be depicted as an astute opportunist, exploiting one of gaping holes left open by Darwin’s loud silences in the Origin to make a name for himself. He did this by fixing his attention onto human origins. He thought Darwin was right (at least in this area; they differed on other topics). He also had no love for Richard Owen, a feud going strong for many years. Huxley launched a scathing and relentless attack on Owen and his claims about the anatomical peculiarity of humans. The press dubbed their clash as the “gorilla wars”.

Huxley examined the anatomy of apes for himself, concentrating on similarities with humans. He reported finding intermediates in the chain of many anatomical features, just as an evolutionist would expect. Huxley specifically announced finding precisely what Owen said was missing in the gorilla: a primordial, incipient form of the hippocampus minor. It wasn’t much. But it was there.

For Huxley this was a triumph. He had discovered a crucial missing link connecting apes to humans. The fact that Owen had made this mistake was delicious icing on the cake for Huxley. Using the well established tools of comparative anatomy, Huxley then argued a simple but crucial point: humans were different from apes only in degree, not in kind. They possessed no feature absolutely peculiar to themselves – no novelties. Most important, the anatomical differences between gorillas and humans were less substantial than those between gorillas and gibbons. If the latter two were placed in the same taxonomic group, Huxley argued, then humans must be included, too. Humanity’s anatomical place in nature, Huxley declared in endless articles and public lectures across the country, was among the apes.

The “gorilla wars” between Huxley and Owen took place in the years immediately following the 1859 publication of Darwin’s Origin. Darwin’s silence quickly became irrelevant. Others keenly contributed, and debate quickly expanded in several directions. One direction stayed focused on the origin of humans as a species. Fossil material, such as specimens of Neanderthal man, were much discussed. However, the material for study remained scant and inconclusive. For decades, this remained so. Another direction focused on physical and cultural anthropology, taking advantage of the considerable experience traders, missionaries, and settlers were reporting in their contact with indigenous people around the globe. Darwinism wasn’t the only (and hardly the first) framework used to give meaning to these experiences. Nevertheless, it added powerfully to the way Europeans interpreted those encounters. To some evolutionists, “savages” became “aboriginals” and “primitive” – primeval in the evolutionary sequence. Much of the energy first focused on the question of human origins from animals quickly shifted in the 1860s to considerations about relations between the world’s many races and questions of hierarchy. This should be no surprise, with contemporary discussion burning over questions of slavery and emancipation, colonial expansion and settlement, and the destruction, then extinction of indigenous peoples everywhere Europeans encountered them. Questions about human origins from apes were quickly lost in the passions set alight over questions about the relations between races.

Higher faculties

Where human origins remained the focus, arguments about brains and bones ultimately made little difference to most people’s thinking about human origins from animals. Regardless of confrontations over features like the hippocampus minor, attention quickly shifted to human qualities collectively listed as the “higher” faculties.

Forget the body. Humans were held to be exceptional owing to their mind and morality. We use tools and complex languages. We exercise reason and develop abstractions, such as complex mathematics. We show sympathy and empathy. We have morality and sophisticated aesthetics. We know anticipation and have a sense of justice. We have a sense of past, present, and future; here and far away. We are aware of the rules governing how we contemplate our place in the world. Humans might be apes anatomically. But the mental and moral divide was described in the 1860s as immense. Unbridgeable. A difference in kind.

On the question of human origins, popular attention quickly shifted towards the higher faculties. How might evolution explain the origin of human intellect, morality, and self-awareness? How did religious instincts originate? How does the soul arrive? Where in the animal world do we find a Michelangelo, Socrates or Confucius?

Such questions stumped evolutionists. Importantly, however, the problem of the higher faculties failed to create a crisis for evolutionary studies. Instead, nearly everyone involved crafted a compromise – a comfortable middle ground that seemed to solve everything. One of the few left unsatisfied with this compromise was Darwin. It was his frustration with this situation that drove him from his silence to speak on human origins early in the 1870s.

Sir Charles Lyell (1797-1875) took up a position in this comfortable middle ground. One of Darwin’s idols and inspirations, Lyell was among Britain’s most senior geologists. His Principles of Geology (1830-1833) set a benchmark for the discipline, especially for defending the notion of deep time – the idea that Earth is geologically ancient – and for charging scientists to seek uniform and constant laws of nature. More than anyone else, Darwin’s identity as a scientist was modelled on Lyell. His book The Geological Evidences of the Antiquity of Man (1863) was widely anticipated to be an expert commentary of Darwin’s views.

In this book, Lyell accepted several basic points about evolution. First, he accepted it occurred in nature. Second, he accepted humans were not recent introductions on Earth. Lyell also accepted the human bodyevolved by natural processes, such as natural selection. But evolution had limits, Lyell argued. It could not explain the finer qualities of civilisation, and it could not produce the human mind or any of the other higher faculties. Though Lyell championed the idea of a law-filled, clockwork universe and thought scientists had a duty to discover those laws, he still kept open the possibility of Divine intervention. Only through such intervention, he argued, could the higher faculties come into being. Lyell argued for evolution in general. He simply added a special Divine boost for humans.

Another occupant of the middle ground was Alfred Russel Wallace, famous as ‘co-discoverer’ of natural selection. Like Lyell, Wallace thought evolution governed nature. At the same time, it had limits. During the 1860s and 1870s Wallace passionately argued that natural processes alone could not create humans complete with our humanity, i.e., our higher faculties. In this case, he said, there “seems to be evidence of a power which has guided the action of [evolution] in definite directions and for special ends.” Wallace was one of Britain’s most passionate defenders of this compromise position. It was one of the most important differences he had with Darwin. “I hope you have not murdered too completely your own and my child,” he told Wallace in 1869 after Wallace published his views on the Divine role in human evolution.

Crudely put, this middle ground position used evolution to explain the origin of the human body. It used Divine intervention to explain the unique origin of the human mind, soul, and civilization. This middle ground was an extremely popular and highly respected position to hold in the 1860s; indeed, it grew into the majority and establishment view.

When Darwin heard such views, he grew ever more angry. This middle ground was a terrible compromise, he thought. He encouraged his friends to avoid it. Lyell knew his compromise angered Darwin, confessing to Huxley how he had simply “could not go the whole orang”.

Nearly alone in establishment circles in his opposition, Darwin complained on two levels. First, he thought the compromise was factually wrong. The higher faculties had indeed evolved naturally from qualities found in animals. Mere prejudice was preventing people from giving that idea a proper test. No intervention was required.

More fundamentally, Darwin thought those in the middle ground had broken a promise they made to science. Scientists, he argued, were supposed to seek universal, constant laws of nature. These operated as clockwork. Whether these laws came into being by Divine design (as even a theist or deist would have accepted) or by some other means, they gave scientists all the tools necessary for explanations of natural phenomena. Of course, even a deist accepted Divine intervention as theoretically possible – calling such events ‘miracles’. But since returning on HMS Beagle (ironically as a new convert to Lyell’s “principles”), Darwin took it as a sign of weakness for a scientist to invoke Divine action when stumped by Nature’s phenomena. At best, such an appeal was inelegant. God’s design would be smarter and less personal than that; it wouldn’t need special intervention. At worst, it was suicidal. What good was a scientific law if it couldn’t explain the difficult cases? What good was science if solutions to the most complex problems needed help from religion?

Darwin aptly summarised both levels of his complaint when he wrote a correspondent in 1860,

“Of course it is open to everyone to believe that man appeared by a separate miracle, though I do not myself see the necessity or probability.” (Darwin to L. Jenyns, 1860)

As the 1860s continued, and as most of his friends and colleagues embraced this compromise, Darwin resolved to break his silence. He had to return the discussion of human origins to scientific ground.

Descent of Man and the Origin of Humanity

Darwin’s decision to publish on human origins came a response to some specific concerns in the late 1860s. First, the problem of human origins had shifted away from bones and towards the origin of the higher faculties. Precisely how and why did those qualities originate? What evidence is left to follow those trails? Darwin felt intense pressure to answer these questions. Second, nearly everyone who commented on human origins failed to “go the whole orang.” Instead, they invoked Divine intervention rather than constant laws of nature to explain the arrival of the noblest of human qualities. Darwin simply had to challenge this compromise.

Descent of Man (1871) and Expression (1872) form one continuous argument. Darwin’s rhetorical strategy for both books was simple: narrow the sense of a gap between humans and animals. He did this by depicting animals as far more sophisticated (i.e., endowed with increasingly human-like qualities) than most people otherwise acknowledged. He also did this by presenting humans as carriers of features which seemed nothing be simple extensions of features found in animals. Differences existed, to be sure. But these were differences in degree, not in kind. Humans have no features peculiar to themselves alone. As Darwin had noted privately many years earlier,

“Compare Fuegian and Ourang-outang and dare say [the] differences so great” (Darwin M notebook 153)

Because Darwin was a latecomer to the discussion of human origins, Descent could rely on a great deal of prior work. In Britain, Huxley had made the definitive argument about bones: anatomically, humans were apes. In Germany, the biologist and ardent evolutionist Ernst Haeckel (1834-1919) did the same. Meanwhile, evolutionary anthropologists were busy assembling the races into family trees, using complex anthropometrics such as cranial capacity, then sending the lines back in time to common ancestors near the ape-human transition (sometimes the lines joined after the transition to humans; sometimes, before). When writing about the anatomical story, Darwin did little more than summarise the work of others and hope more hard evidence would be unearthed to complete our understanding of humanity’s earliest days.

Quickly in the Descent, Darwin turned his attention to mental, intellectual and moral faculties. First, he complained how frequently observers underrated the faculties of animals, then he gave accounts of a myriad of supposedly human qualities found in some form in animals: foresight, memory, reason, imagination, love, jealousy, ability to learn from mistakes, wonder, curiosity, attention, tool use, inarticulate language, sense of beauty, and aesthetics. With every case, Darwin’s strategy is clear. First, find human-like qualities in animals to show the absence of human exceptionalism and to make animals seem less brutish. Second, identify primal examples of faculties in humans. Third, draw the two ever closer together to show the difference in degree, not kind.

Consider the origin of religion as an example. Darwin agreed it was absurd and insulting to suggest animals had religious sentiments akin to the Abrahamic faiths. Rather, his thinking began with a widely accepted view in Victorian Britain about a progressive, positivist hierarchy existing among religions: animism (spirits living free in nature) was the primeval form of worship, later supplanted by polytheism, then monotheism. This continuum showed slow, gradual transformation. Such a chain of reasoning gave Darwin the “fact” requiring his explanation: animism was the human condition needing connection to the animal world. As a speculative suggestion, he told a story about one of his dogs, probably Bob:

“The tendency of savages to imagine that natural objects and agencies are animated by spiritual essences is, perhaps, best illustrated by a little fact which I once noticed: my dog, a full-grown and very sensible animal, was lying on the lawn during a hot and still day but at a little distance a slight breeze occasionally moved an open parasol, which would have been wholly disregarded by the dog had anyone stood near it. As it was, every time that the parasol slightly moved, the dog growled fiercely and barked. He must, I think, have reasoned to himself in a rapid and unconscious manner, that movement without any apparent cause indicated the presence of some strange living agent, and no stranger had a right to be on his territory.” (Darwin 1871)

Then Darwin reminded his researchers of the Fuegians he observed so many years before on the HMS Beagle voyage. They thought nature was filled with spirits, especially evil ones. That didn’t seem so different to Darwin. The origin of our humanity came a step closer.

Much of the theoretical discussion in Descent was devoted to sexual selection, essentially natural selection focused on competition for mates and grounded in choice and signalling. Crudely put, this was an additional mechanism Darwin proposed for Nature driving the development of some higher faculties. For example, he thought it hard not to look at a male peacock’s plumage or a male mandrill’s bright face without thinking a sense of beauty, ornament, and decoration somehow was perceived by the animals involved. The origin of aesthetics was a critical problem to solve for Darwin, and sexual selection helped. Likewise, Darwin emphasised circumstances where natural selection favoured cooperation and community over individualism: consider social insects to flocking behaviours in birds. Group selection helped him slowly grind towards organised human societies.

Descent moved Darwin closer to his targets. He wanted to demonstrate how a few simple laws of nature could produce each and every special faculty in the human story. No Divine intervention. No appeals for special treatment. Darwin was going to boldly ‘go the whole orang’. Not only would this show the power of his own explanations. It also would return the discussion of human origins to within proper scientific boundaries of materialism and positive knowledge. As he said in 1860, Divine intervention seemed to him as unnecessary for science as it was improbable.

Expression of Emotions is the Sequel

Darwin had been collecting information on expression and emotions since at least his travels on HMS Beagle. He closely observed his own children, too, beginning with the birth of his first son in 1839. As with so many other projects, Darwin slowly amassed information in this area, not precisely sure what might come of it. His research into human origins expanded in the 1860s, and his collecting became more focused. It’s often said Darwin wrote Expression in a few short months, sandwiched between correcting proofs of Descent and starting revisions for the sixth and final edition of the Origin. This certainly is true of the book in terms of the manuscript. But Darwin had been stewing on this subject for a long time. His initial plan was to include a chapter on expression in Descent. However, as his writing grew in bulk, and with topics like sexual selection already overburdening his manuscript, Darwin changed his plan. Once Descent was off his plate, he would turn to a “little book” on expression and give his thinking the space it deserved.

As with all of Darwin’s work, modern readers should follow Expression on two levels: content and method.

Regarding content, the purpose of the book is straightforward. First, Darwin sought to identify the chief expressive actions produced by humans. He placed his emphasis on involuntary and habitual expressions – the less conscious the better. His table of contents showed the long list of cases open to study: grief, despair, joy, devotion, hatred, guilt, astonishment, and so on. With such a range Darwin aimed only to be suggestive, not exhaustive.

Second, Darwin described these emotions in minute skeletal and muscular detail. His taxonomist’s eye worked to create exhaustive, and exhausting, descriptions of every element he could locate. This was exacting work, as demanding as his earlier studies of barnacles, orchids, and climbing plants. Even the most fleeting elements of expressions were important to him. Though Darwin concentrated his attention on facial expression, he frequently added descriptions of other body movements, too. He did the same for expressions in animals.

Third, Darwin proposed a series of principles to explain why humans have the expressions they do. Some, he said, came as part of an involuntary venting by a nervous system overwhelmed with emotive force. A terrified man shivers. A nervous man perspires. Other expressions resulted from habitual actions useful at some moment in the past and eventually embedded into involuntary action. Fear causes hair on the back of the neck to rise. Anger brings men sometimes to show their teeth. Odd and hard to explain in isolation, these responses were golden examples for Darwin as they seemed to require an understanding of ancestry and inheritance. (That these involuntary actions so often seemed similar to animal behaviours rarely went without comment.) Still other expressions seemed tied together as opposites. Smiles and frowns seemed to him opposite responses to what he called “antithetical” emotions, such as happiness and sorrow. Antithesis was an important explanatory tool for Darwin, as it bound together otherwise separate phenomena.

Modern readers obsess about the answers Darwin gave. To him, methods were equally. Darwin thought his three explanatory principles had wide application, though he also accepted the possibility of others. In their detail, those principles were not well received. Regardless, readers understood his point well enough: humans have certain expressions because they are inherit from ancestors who used them as signals for non-verbal communication.

Darwin was determined to “go the whole orang,” by invoking only natural processes when explaining the origin or function of expression. That Darwin restricted himself in this way also was well understood. Indeed, it was hard to miss. Darwin took up this theme immediately in his introduction with dramatic sketches of facial muscles (Figures 1-3) and a commentary about Sir Charles Bell’s theory for their origins. A distinguished anatomist and natural theologian, Bell saw elegant, Divine design in the complexities of human anatomy. The hand was his star example. Likewise, Bell argued design explained particularities in human facial expression, with only humans having muscles for the expressions which created our complex and subtle emotions.

Darwin aimed to systematically dismantle this view. First he worked to demonstrate those facial muscles were not unique to humans; then, to show our expressions were merely co-opted versions of expressions found in animals, haphazardly assembled into new working combinations. This was patchwork reorganisation, not elegant design. Darwin wanted to show he didn’t need Divine design for his explanations. Even expressions evoked by moral sentiments – e.g., embarrassment and shame signalled by blushing – dissolved for him under closer scrutiny. This dissolution into natural process was one of Darwin’s chief aims with Expression. A reader focusing only on the answers he gives will miss the point entirely.

Gathering Data for Expression

Expression was not meant to be read as a novel. It’s an encyclopaedia unified by several core ideas. Some reviewers thought Expression an excellent natural history of expression – solidly researched and useful for comparative purposes and classification – even though they had little time for his theory of descent. Modern readers often overlook the painstaking self-awareness Darwin devoted to his methods. Expression offers an ideal example of that self-awareness (and how it sometimes was ignored).

Darwin didn’t simply amass data in unguided ways. He was selective both for depth and breadth. In depth, he built stocks of the same phenomena to prove he works with real problems, not aberrations or special cases. In breadth, he built his stocks conscience to cover as diverse a range as possible. Certainly, he presented himself as the good British empiricist, smothering readers with facts. More importantly, Darwin valued theories linking facts that seemed otherwise disparate and unconnected, a principle known as consilience. Modern readers often find Darwin’s empirical approach turgid and exhausting. By his standards, however, the wider a theory’s range of application, the better. Darwin used the same approach throughout his life, including for the Origin and the Descent.

To collect data specifically on expressions, Darwin used many methods. He explained these in his Introduction.

Gathering information from others. Contrary to popular myth, Darwin never worked in isolation, and he was not a recluse. He simply carefully managed access. Darwin’s vast correspondence shows him eagerly drawing information from enthusiasts and observers around the world and throughout his social and domestic life. Darwin was masterful in the way he enrolled others into projects. When he became famous after the Origin, that assistance was easier to request and far more easily given. All the while, Darwin was generous with credit. He could afford to be. Besides, Darwin didn’t want to be seen to be working in isolation, as a lone crank without standing in the community. Darwin knew there was strength in numbers. In all his books, he made reference to the assistance of others. Expression was no different, as even a cursory reading of his Introduction makes clear.

Observing infants. From the birth of their first son in 1839, Darwin made a habit of closely observing his own children and those coming into his domestic life. Darwin also queried family friends and their wives about the habits of their children. This wasn’t idle chat; it was probing research. Darwin focused on infants because he expected them to express emotions with extraordinary force and in simple and pure forms. He hoped to find more involuntary reactions, too. At the same time, he was well aware how quickly children learned to manipulate expressions for their own ends.

Studying the insane. Darwin worried that the genuine, original expression of emotions often was masked by cultural filters. He thought this could be remedied by studying not only infants but also those seemingly immune to learning those filters. This was the reason he sought information on the insane, eventually coming into correspondence with Sir James Crichton-Browne (1840-1938), physician and psychiatrist working at the West Riding Asylum near Wakefield. Darwin made much use of the information provided by Crichton-Browne, especially for thinking about his observational methods and for considering the differences between normal and abnormal expressions. The insane, he said, were liable to the strongest passions and were relatively incapable of filtering them out or gaining much control over them. Some of the photographs Crichton-Browne sent to Darwin, preserved in his archives and previously unpublished, are reproduced here as Supplemental Images 1-6.

Painting and sculpture. As a cultivated gentleman, Darwin was certain to look to the fine arts for examples of expression. He worked his way through the classical cannon of paintings and sculptures, as well as through popular picture books of his day. Ultimately, this search proved less helpful than other techniques. If anything, it provided Darwin with more qualifiers for his methods. Expression often was fleeting, and it was extremely difficult to capture in hindsight. Not only was much visual information communicated subliminally, but observer unconsciously imposed interpretations onto their observations, extrapolating and imposing. For a scientific study of expression, this would not do.

Electric shocks. Some of the most striking images in Expression are the contorted faces of a man whose face has been shocked (Plate 3 and Figures 20 and 21). These were produced by the French neurologist Guillaume Duchenne (1806-1875), who published a treatise of the anatomy of facial expression in 1862. With permission, Darwin used some of Duchenne’s images. More from Duchenne’s research are provided here as Supplemental Images 9-14. This research gave Darwin a great deal to consider.

Duchenne sought to understand which muscle combinations produced particular expressions on the face and how the underlying nerves produced these actions. He developed a technique for applying electrical charges to (galvanizing) specific muscles of a living patient’s face. His main subject, recorded only as the “old, toothless man,” had little feeling in his face so could withstand the seconds-long stimulations needed for Duchenne’s observations and for the exposure time required by the photographic methods. The electrodes are clearly seen in Supplemental Images 11-14, though sometimes there were removed in published versions such as the illustrations in Figures 20 and 21. Duchenne used his galvanizing system to classify the muscles of facial expression, including anger, sadness, fright and attention.

Duchenne mastered this technique. He could stimulate single muscles on the face or build particular combinations. He discovered some expressions (e.g., signalling joy, pain) were produced from the action of single muscles; others, from combinations. He also found he could compose complex expressions simply by combinations of simple, single-muscle ones (e.g., signals for discomfort by combining joy and pain). Duchenne gave special attention to understanding the difference between “real” and “false” expressions, concluding they differed in the action of involuntary muscle movements. He also discovered various optical illusions of facial expression in which the whole face seemed to change from the action of one muscle movement on a small region of the face. The coverings over parts of faces in Supplemental Images 9 and 10 are attempts to study such phenomena.

Summarising his work in 1862, Duchenne argued facial expression was a universal non-verbal language in place at birth. It is no surprise Darwin found this work fascinating, and no surprise he made much use of it when preparing Expression. Duchenne’s images are arresting. At the same time, it’s easy to make too much out of their visual impact. One important use Darwin had for Duchenne’s study was to turn it against Sir Charles Bell’s natural theological theory of facial muscles. Duchenne’s work showed how far the facial muscles were from a neatly organised system for expression. Rather, facial signals seemed haphazard, ad hoc, and inelegant. This aided Darwin’s overall view that human expressions resulted from a long accumulated series of changes occurring in our evolutionary past.

Queries sent abroad. Darwin sought comparison across as much of humanity as possible. Of course, he had his own, now dim, memories from HMS Beagle. He also had anecdotal information from many correspondents. For instance, in early 1860, Darwin asked a missionary in Tierra del Fuego for a long series of observations about expressions and emotions in Fuegian “savages”. For instance,

“Do they express astonishment by widely open eyes uplifted eyebrows and open mouth?”

“Do they express contempt by the same gestures as we do, namely by turning up nose and puffing out their breath or even spitting?”

But he wanted more. Importantly, he wanted to narrow the frame of his observers, asking them to comment from immediate and specific experience rather than vague memory and retrospective anecdote. In 1867 he assembled a list of detailed questions, then paid to have these printed onto a one-page circular. (The questions are listed in the Introduction to Expression. These are only slightly altered from the printed circular.) Beginning in 1867-68, Darwin distributed this circular both to correspondents and to organisations, such as missionary societies. It’s not known how many copies he had printed or precisely who received them, but clearly, his Queries reached unexpected places. For instance, it was reprinted in the Annual Report of the Smithsonian Institution for 1867 (1868). Approximately three dozen replies eventually arrived at Down House. Some of this information was acknowledged in Expression.

This form of printed Query was not original to Darwin. He might have been copying this method from his half-cousin Francis Galton (1822-1911). Original copies of Darwin’s circular are extremely rare. Only in the 1970s did historians understanding the process of its creation. Modern experts in survey methods will describe Darwin’s method as haphazard and unrepresentative. It certainly was. However, rather than judge Darwin from twenty-first century standards, readers should appreciate his attempt to add more – and more range — to the mountain of data he had already amassed. Darwin was looking for similarities to examples already known to him. He also was looking for novelties his theory might additionally explain.

Darwin had specific views about the origin of human races, and these fed into his analysis. In brief, he thought humans arose once as a species, then the main races arose in response to local circumstances. Underneath their many differences, however, all humans have an underlying unity of common qualities. Among these, Darwin included all the basic forms of expression he studied. In a way, the comparative work – from Fuegians to Shakespeare; from Maoris to his own children – was intended to underlie this unity. The attempt of his Queries to reach across the globe in studying humans helped Darwin reinforce his view that people everywhere formed fundamentally one group.

Comparisons with animals. The goal of studying expression in animals, of course, was to trace the continuity of expression – more precisely, the continuity of habitual movements associated with expressions. As with subjects in the Descent, Darwin endeavoured to close the gap: presenting animal actions as human-like, and human actions as little more than what is observed in animals. The focus on expressions allowed him to neatly bypass speculative questions about the emotional life for animals (though this bypassing was selective; he did not avoid it when discussion seemed useful). Most of the detailed descriptions came from familiar domesticated animals: snarling dogs, startled horses, nesting kittens, and so on. This included Darwin family pets, such as Bob, the dog whose sulkiness was recorded in Expression, and Polly, especially for her affection and her instinctive pointing. For exotic animals, Darwin had distant firsthand knowledge and notes collected most systematically from the Zoological Gardens in Regent’s Park, which he often visited when the family lived on nearby Upper Gower Street. The famous sulking chimpanzee (Figure 18) is a good example of such observations. Of course, Darwin also made extensive use of information contributed by friends and correspondents around the world. Anecdotes were easy to collect.

Photographs. Expression was one of the first British books to incorporate photographs as part of its evidence base. These were included to illustrate particular points, rather than to reveal novel discoveries. The heliotype printing process his publisher used was a new technology in the early 1870s. Its use made the inclusion of photographs far less expensive than other processes. Still, Darwin argued repeatedly with his publisher to include more. In part, this was a matter of convenience. Darwin noted his considerable frustration when describing expressions, often too delicate and subtle to describe. In such cases, photographs were indeed worth thousands of words.

Always interested in new technologies, Darwin was fascinated himself with photography, encouraging his sons to experiment at home. As his systematic collection of material on expressions expanded in the middle 1860s, Darwin trawled through many photographic collections in search of useful material. He studied commercially available books of photographs. He visited studios and discussed the subject with many photographers. One particular favourite adviser for Darwin was Oscar Rejlander (1813-1875), who provided many of the images in Expression and who even appears himself (Plate 4 and 5). He also sent his family on reconnaissance errands, and asked correspondents for materials. Darwin acquired more than 200 photographs during his study of expressions, and he certainly examined countless others while searching. Expression is heavily influenced by the new visual culture of photography. The historian Phillip Prodger has written definitively on the photographs published in Expression and on those found in the Darwin archives at Cambridge University Library (see Further Readings below).

As powerful as many of the photographs are in Expressions few were spontaneous, and all require qualification. Photographic equipment of the 1860s and 1870s required relatively long exposure times, so poses had to be held. Many expressions in Darwin’s book were simply mimicked as an actor might (e.g., Plate 4 and 5; compare these with Supplemental Images 15 and 16, or Rejlander’s open mimicry in Supplemental Image 19). Other images were modified in the production process. The crying baby in Plate 1.1 – a famous image of “Ginx’s Baby” from the 1870s – in fact is not a photograph but a drawing based on a photograph, with subtle artistic license added. Viewers should beware, as there is more to these images than meets the eye.

Still, Darwin was keen to explore the value of photography for his purposes. Using photographs from Duchenne’s galvanizing experiments, for instance, Darwin tested the consistency with which people interpreted expressions. Showing them to dozens of family, friends and visitors to Down House, he noted much variability – only a few expressions were described consistently by his viewers. Darwin also found that if he hid the description even from himself, he might not always accurately identify the expression on display. From this, he made a note about the power of bias on interpretation. Along the same lines, Crichton-Browne’s photographs brought poignancy to Darwin’s appreciation for the widest range of abnormal and extreme human expression. Though he did not include these in the book, they certain influenced his principle of expressions due to a nervous system overwhelmed with emotive force. Darwin’s careful marking of draft figures for Expression also shows him well aware of the power of visual images in communicating information. He wanted to make sure they were correct and clear (see Supplemental Images 21, 22, and 24).

Publishing Expression

For the domestic market, Darwin’s publisher expected good sales from Expression, but even they were surprised by massive interest during previews. He wrote to Darwin,

“…the reception of your Expression by the Booksellers yesterday even exceeded my expectations – not less than 6000 have been taken … The modest way in which you introduced to me your new work on Expression a little misled me as to its probable reception—- I had not made allowance for the immense popularity of its author. Long may it last …” (John Murray to Charles Darwin, 9 November 1872)

Darwin’s publisher printed 7,000 copies in the first issue, formally publishing on 26 November 1872. Within a year, Expression was in its 10th thousand printing. This saturated the market; copies were still available after Darwin’s death in 1882. Darwin made no revisions to later printers, though the configuration of the photographic plates changed in trivial ways.

Darwin was in his early sixties when Expression appeared. He knew how to promote his own work, writing internationally to ensure translations and reprints. He no longer left such matters to chance; nor did he care to create opportunities for unauthorised editions or poor-quality translations. For North American markets, he agreed to an “authorized edition” published by D. Appleton and Company in 1873. This became the basis for reprints in the United States well into the twentieth century. Translations of Expression appeared in Russian (1872), German (1873), Dutch (1873), Polish (1873), French (1874), and Italian (1890). Much later, other translations appeared, including Chinese (1996), Spanish (1998), and Portuguese (2000). Some of these translations took on an independent life, with new translated “editions” later published as new printings. especially the German.

Darwin published one edition of Expression in his lifetime. A revision did not seem a high priority. At the time of Darwin’s death in 1882, John Murray’s tenth thousand printing had still not completely sold, so likely Darwin was under no pressure to produce a revision. Beside, from his publisher’s point of view, other projects were selling even better and there seemed no reason to look back.

Nevertheless, a second edition appeared in 1890. Darwin’s son, Francis (1848-1925), had appointed himself heir to his father’s literary estate. He decided a revised edition of Expression was indeed on his father’s list of priorities, so he set himself the job of editing it. Francis found a collection of material his father had assembled for further discussions of expressions – “a mass of letters, extracts from and references to books, pamphlets and reviews”. He also deciphered pencilled comments found in the margins of his father’s own copy of the book. The result is an edition different in some details, with a few corrections and additions, but it is the same in overall structure, reach and argument. The majority of Francis’s additions appear as footnotes contained in square brackets (as they are reproduced in thie Penguin Classics edition). Francis made only minor changes to the main text, mostly punctuation. These were not indicated. The images were different. They were mostly photographed directly from the first edition, and many appear reversed horizontally in the 1890 edition. This altered their semantic content. (This Penguin Classics edition restores the form of the images to their first edition with newly photographed images for maximum quality.)

Francis Darwin’s 1890 edition has a confused publication record. Francis dated a “Preface to the Second Edition” as 1889. The book appeared for sale in 1890. Later commentators and bibliographers have confused these two dates. Some copies of this 1890 edition bear a title page noting it as a “Second Edition”; others as “Eleventh Thousand”. A further printing was done in 1901, as the “Twelfth Thousand”. Later printings of this edition carry the tagline, “popular edition”. In the twentieth century, Expression was often reprinted, using the Appleton 1873 text as the core. Francis’ 1890 edition quickly feel by the wayside, normally available only in specialised scholarly settings. This Penguin Classics edition is the first widely available printing of the 1890 edition.

In 1998 Harper Collins published what it called the “third” or “definitive” edition of Expression. This edition contains excellent research by Phillip Prodger into the photography and illustrations used in Darwin’s book. The volume’s editor, Paul Ekman, also inserted a few minor changes to the text that Francis Darwin chose not to incorporate into his 1890 edition. Ekman had a specific reason to reprint the Expression. At the time, he was developing his own theories about facial expression, their natural history, and their universality. His edition of Expression was an attempt to put Darwin to work for that project. In the process, Ekman inserted an intrusive running commentary into the text, identifying Darwin’s successes and failures as a researcher and pointing to subsequent work moving the study forward. Ekman’s editorial hand was overbearing, jerking readers between past and present in a fashion that does justice neither to Darwin’s original nor to Ekman’s own elegant and path-breaking research.


On first glance, Expression seems a peculiar book: crying babies, nagging cats, dogs barking at spirits, and photographs of faces being shocked with electricity. More than a few casual readers have dismissed this project as the miscellaneous ramblings of a scientist long past his creative prime. Nothing could be farther from the truth. Expression is a central pillar in Darwin’s argument about human origins. It is a book entirely typical of Darwin’s many projects in its use of assistance from many people, its efforts to integrate a wide range of literature, its long gestation, its intricate descriptions, and its smothering by weight of evidence. Most important is its search for rational, naturalistic explanations. In short, Expression is an exemplar of Darwin’s approach to the scientific study of biological problems.

Expression is also typical of Darwin in another important respect. He wasn’t perfect. Darwin didn’t solve every problem, nor was he always right in his answers. Darwin sometimes obscured more than he enlightened. He sometimes made mistakes. He often left some of the hardest problems (e.g., the nature of the religious soul) to others. The twenty-first century has begun with a triumphalism about Darwin that is, at times, fanatical. His genuine importance is obscured by hysterically grand attributions and adoration. In providing a clean, uninterrupted view of Darwin’s discussion of Expression and the origin of humanity, this Penguin Classics edition aims to present his work for the simple project it was: an honest attempt to observe the world around us and explain how it has come to be. No other reason is needed to admire Charles Darwin or his published work.

Charles Darwin, 1890. The Expression of the Emotions in Man and Animals. Second edition. (Penguin Classics) Edited by Joe Cain and Sharon Messenger. ISBN 978-0141439-44-0.Read Darwin’s Expression of Emotions

If you want to read Darwin’s book, the Penguin Classics is a fantastic choice. It reprints the 1890 second edition, for important reasons. 

  • Darwin, Charles. The Expression of the Emotions in Man and Animals (Penguin Classics). Edited by Joe Cain and Sharon Messenger. ISBN 978-0141439-44-0.

Joe Cain (2008)