# Popular Science Monthly/Volume 45/July 1894/On Acquired Facial Expression

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* ON ACQUIRED FACIAL EXPRESSION.
By LOUIS ROBINSON.
ALTHOUGH from infancy upward we are all, whether we know it or not, close students of physiognomy, and although a number of books, the result of much careful research, have been published upon the scientific aspect of the subject, there are certain facts connected with facial expression which, though often remarked upon, have never received explanation. With two of these-both of which bear upon the causes of acquired expression of a more or less permanent character—I propose briefly to deal in this article. I refer to the similarity of visage displayed by nearly all members of certain trades and professions; and to the likeness which often becomes apparent on the faces of people (generally married couples) who live together.
In addition to the bony framework, there are three chief anatomical factors which go to make up the expression of the face. These are the skin, the subcutaneous cushion of fat which contains the numerous blood-vessels, and, lastly, the facial muscles. The nerve supply is abundant and peculiar. The integument receives sensory branches from the fifth cranial nerve, the blood-vessels are under the control of the sympathetic system, and the muscles which have to do with expression receive motor impulses from the brain via the seventh cranial or facial nerve, first accurately described by Sir Charles Bell. It is to these numerous slips of muscular tissue, with their controlling telegraphic nerve fibers, that I wish especially to direct attention.
It is, of course, obvious to all who have an elementary knowledge of physiology that any movement of any part of the face is owing to the contraction of certain muscles, and that every such contraction must take place at the command of an impulse conveyed to the muscles by means of the motor nerves.
Into the historical evolutionary explanation of these movements it is not my intention here to enter. Let it suffice to say that there can be little doubt that they one and all represent some adaptation of the bodily structures to certain physical needs (possibly long obsolete) which accompanied the emotions of which the movements are now an index; just as the wagging of a dog's tail, which is now regarded as a mere sign of pleasurable excitement, was in the first place of vital importance as a signal to his comrades that game was afoot.
The connection between the muscles of expression and the emotional centers in the brain is of a most intimate character, and is largely independent of the will, although by strong volition any consequent movement of the features may generally be ​vented. That the association is instinctive, and not acquired through individual or racial education, is shown by the fact that the facial changes which accompany the sentiments of fear, hatred, contempt, merriment, or mockery are practically identical the world over.
The extreme rarity of the man who can always keep his countenance, even when his will is fully awake, is as complete a proof of this intimate and automatic bond between the mental apparatus and the facial muscles as need be brought forward. Are we not all aware of exercising a restraining effort upon our features when we endeavor to hide our emotions? And is not the common phrase, "He gave way to his feelings," a recognition of the fact that the invariable instinctive tendency is, when the emotions are stirred, to yield to those outward manifestations which are obvious to the eye of another, and which are the results of motor nervous impulse?
Now, this fact is most important in the study of what may be called "static physiognomy," which treats of the interpretation of habitual expression when the countenance is at rest. It shows that in all probability every emotion, however slight, sends an impulse to the appropriate muscles, although the immediate nervous provocation may be much too faint to produce any marked movement. That such trivial and evanescent nerve impulses, although their effect may be at the time unfelt by the subject himself and imperceptible to lookers-on, may be, if often repeated, efficient factors in the formation of a habitual cast of countenance, I shall presently show.
It is plain that such effects will become more perceptible when the first rotundity of youth has disappeared. We naturally look at a young face for a prophecy, and at an old one for a record. But the materials from which we attempt to inform ourselves are of a very different character in the two classes. In the one case we see a general arrangement of features, which, according to some utterly inscrutable law, accompanies certain traits of mental and moral character. No satisfactory theory has ever been put forward to account for such facts as that human beings with a certain inherited squareness of jaw are always of a tenacious disposition.
But when we scrutinize an older face, we peruse the linear inscriptions upon its surface as we read a book of which we know the author. Not only do such and such conformations of its lines have a definite meaning, but we can form an opinion as to why and when (if not now) they were written. The caligraphy, of course, is not uniform in all cases, and there are various complexities about it which may render an exact interpretation a matter of difficulty. Trouble or passion, which in one instance is ​recorded in bold characters, in another may leave scarcely a visible mark; and it is obvious that a lean face will betray the story of emotional experience more readily than one covered with a mask of fat and smooth skin.
If we look at an anatomical representation of the human face with its integument removed, we see at once that the various groups of muscles are generally so arranged as to balance one another. Thus there is one set of muscles for opening the eyes or the lips, and another set for closing them; one group raises and another depresses the angles of the mouth, and so on. All these muscles, even when the features are quiescent, maintain a certain tone; for it is found that if one part of the face is paralyzed, the sound muscles near it draw it toward them and retain it there even when they are at rest. If one of the muscles or groups is stronger in proportion than its opponents, it will cause a marked change of expression, as is plainly seen in partial paralysis. It is a familiar fact that all muscles become larger and stronger through exercise; but the reason why they so increase is not such a simple matter. The vitality of muscular, and indeed of all other living tissue, is strangely under the influence of the nervous system. If the nerves which supply a limb are totally destroyed, it shrinks with extraordinary rapidity, although the main blood supply remains perfect. At the same time a limb may be paralyzed as to motion and yet undergo but little wasting, because certain nerve fibers (called trophic, because they have to do with nutrition) are left intact. In bedridden patients, again, in spite of a total want of exercise, the muscles often do not shrink in any great degree. Hence we see that nervous currents or impulses may influence the growth of a muscle apart from actual exercise.
Let us take an instance, the too visible results of which every one is familiar with. Persons who squint (with certain exceptions I need not here specify) are always "far-sighted"—that is, the convex lens of that marvelous living camera, the eye, is not quite convex enough; and in consequence its focus is too long to permit rays from a near object to form a clear image on the retina. If the retina could be pushed back away from the lens the difficulty would be overcome; but we can not, as in the case of an opera glass or a photographic apparatus, lengthen the space between the lens and the spot upon which the image is to be projected to any great extent, so Nature has provided a focusing apparatus in the crystalline lens itself. By a muscular effort the elastic lens can be made more convex, and in this way the focus is shortened to the required length. In long-sighted or flat-lensed persons this is constantly being done when they are reading or looking at some near object.
Now, it so happens that one of the little muscles which move ​the eyeball—i. e., the internal rectus, which rolls the eye inward toward the nose—gets its nerve supply partly from the same source as do the muscles for shortening the focus of the lens. The latter, in far-sighted persons, are constantly being urged to action by impulses proceeding from the brain along the nerve, and part of the impulse invariably finds its way, owing to the intimate relation of the parts, to the internal rectus muscle. This muscle does not at first respond to the stimulus sufficiently to turn the eye inward every time the lens is accommodated for near objects; but the result of this nervous stimulation is in the long run the same as if the internal rectus were constantly called into action by a deliberate exercise of the will. It greatly increases in bulk and strength, and outpulls its opponent on the outer side of the eye (which gets its nerve supply from a different source), and so the balance of power is destroyed and a hideous inward squint is produced.
From this we can understand the effect of a long-continued dominant emotion on the face, even although it may exist in an individual too well bred to allow his countenance to be easily distorted by the prevailing passion. Whenever the thoughts take their habitual direction, a stream of nervous influence from the brain to the hidden-expression muscles is the inevitable concomitant. The closest observer may not notice the least change of outline or the vaguest tremor of movement at the time, and the subject himself may be unwarned as to what is going on. Yet in the course of years the muscles so stimulated assert themselves over the others, and a permanent expression in accordance with the mental character comes out.
Close observation of almost any face under favorable circumstances supports this view. While engaged in studying the phenomena of sleep, I have repeatedly noticed that the apparent placidity of the features during slumber is deceptive. Even in dreams each fleeting emotion affects the facial muscles in some degree, and the apparent calm on the surface covers many little eddies and currents beneath, as one or other of them is thus provoked into partial activity. When the thoughts are all-absorbing and the owner of the face is off his guard, it does not require a very acute observer to see how the expression follows what is in the mind.
The other day, while traveling by train, I witnessed the parting of a pair of lovers. The damsel got into the carriage where we were seated, and until the train started there was an eloquent interchange of glances and smiles. As we steamed off, the last smile of parting gradually faded on the lassie's face. She shut her eyes and leaned back, so that she did not see that she was under observation, and at the same time the light showed her ​countenance with, great distinctness. For the space of some twenty minutes, during which. I was her fellow-passenger, the dimples of that parting smile would ever and anon appear, but in so slight a degree that, unless the opportunities for observation had been exceptional, they would not have been noticed. The movements of the muscles were so subtle that it was absolutely impossible to analyze them, or even to discern them severally. They were
". . . like the borealis race, That flit ere you can point their place."
Yet one could gauge from moment to moment the depth, and to some extent the nature, of her thoughts of her lover.
Let me strongly recommend all physiognomists who travel by rail not to spend their time in the perusal of text-books, while they have before them a row of living documents inscribed all over with the very aphorisms of the art. The opportunities for observation afforded by the British traveling hutch are such as to make one forgive its manifold inconveniences. Take the instance of the old lady who is perturbed about the safety of her ticket and her luggage. Her totality of expression has a heavy groundwork of care, upon which start and flicker endless additional lines, as this or that possibility of trouble crosses her mind. It requires some self-restraint on the part of the enthusiastic student to refrain from making such a one the subject of physiognomical research by hinting various moving hypotheses concerning the perils of the journey or the fate of her numerous packages. Let him not forget, however, that although such experiments are not forbidden by the Vivisection Act, the methods of Parrhasius are out of harmony with the spirit of the nineteenth Christian century.
The incessant flow of involuntary nerve-currents to the facial muscles doubtless accounts for the odd similarity of expression among men of the same vocation. In many such cases the conditions are so complex that it seems impossible to lay one's finger upon the special items of environment which conduce to the facial characteristics exhibited by nearly all members of certain trades and professions. What, for instance, is there about the process of making shoes which evokes the unmistakable cobbler's visage? The portrait of Edward, the Banff naturalist, in Mr. Smiles's book, shows the type in a marked degree. As far as my own observation carries me, the cause must be looked for in the last, lapstone, and wax-end of old-fashioned cordwainery; since men who work the machines in modern boot factories, or who do ordinary repairing, do not exhibit the expression. It appears probable that the tailor's distinctive type of face may have ​been partially created by his habit of working bis jaws concomitantly with his shears. Let any one watch a person cutting a piece of tough material with scissors, and he will see that the lower part of the face wags in rhythmic and spontaneous unison with the blades. Shepherds and farm laborers who join sheep-shearing gangs certainly acquire a different expression while engaged in this kind of work. The cast of countenance by which one so easily recognizes a groom is partially explicable from the fact that the muscles which close the jaw and compress the lips are always called into play when we are asserting our will over that of a horse. Nearly all jockeys and other horsey men have a peculiar set of the mouth and chin, but I have been unable to distinguish any special characteristic about the eye or upper part of the face. It is instructive to compare the visage of the ruler of horses with that of the ruler of men. The horseman's face shows command in the mouth, the drill-sergeant's in the mouth and the eye. The last is undoubtedly the most effective instrument in exacting obedience from our own species. Here we get a hint of the cause of that want of dignity, that element of coarseness, which is discernible in the countenances of some men and women who have much to do with horses. The higher and nobler method of expressing authority is outweighed by the lower and more animal one.
Generally speaking, it is a strenuous contest with minor difficulties which produces a thin and rigid set of lips. It is seen almost invariably in housewives of the Martha type, who are "careful and troubled about many things," and whose souls are shaken to the center by petty worries within doors, and strife à outrance with shortcomings of the scullery maid or the cook.
The compressed lip so loved (and so often misinterpreted) by novelists is a sign of weakness rather than strength. It tells of perpetual conflicts in which the reserves are called into the fray. The strong will is not agitated into strenuous action by the small worries of the hour, and the great occasions which call for its whole forces are too few to produce a permanent impress of this kind upon the features. The commanding officer, assured of bis men's obedience, does not habitually keep his lip muscles in a state of tension. Look at the sea captain, the most absolute monarch on earth. He carries authority and power in his face, but it resides in his eye and the confident assurance of his easily set mouth. Every spar and shaft and muscle in bis floating realm must obey him, and he knows it. This is probably a reason why the sea captain's and the engine driver's show a certain similarity of type. The engine driver can make bis captive giant, strong as ten thousand men, obey the pressure of his finger. His lips are usually calm, like those of the statues of the wielder of ​thunderbolts on Olympus. Who ever saw a man commanding a man-of war or driving a locomotive with the contentious lip of a school usher?
The typical expressions of the members of those three liberal professions which Sir Thomas Browne says are all founded upon the Fall of Adam are well enough recognized to have been long the prey of the caricaturist. The several distinctive traits of each, and the possible causes which give rise to them, are too complex to be dealt within a single article. Speaking very generally, the cleric's face is indicative of authority (of the thin-lipped kind) and of a dignified sense of the sanctity of his office. The doctor's jaw and mouth are less rigid, yet tell of decision. His eye is vigilant and sympathetic, and his whole facial aspect conveys the idea of a fund of untapped wisdom. The lawyer's countenance is confident and confidential, with a pouncing alertness of the eye, and a prevailing expression of weighty perspicacity.
Of course it must be understood that in such a summary one is dealing with the broadest generalities. Marked exceptions to the rule for each class will be within every one's experience. I am inclined to think that in the learned professions the facial characteristics are much less marked than formerly. This may partly be accounted for by the modern laxity of fashion as to shaving the lip and chin. But also, there can be little doubt that the custom of carrying a sort of perpetual personal trade-mark is diminishing. Military officers no longer wear their uniform in private life, and the doctor and lawyer have both acquired a weakness to be classed, socially, as human beings.
It is noteworthy (and here my own observation has been supported by one of the most alert minds of this generation) that the leading members of the medical and legal professions do not display the facial symbols to anything like the same extent as the rank and file. This is especially so with regard to the expression of the mouth, and may be due to the absence of that anxious endeavor to look like a wise doctor or lawyer which possesses most ordinary practitioners in their earlier years.
The fact that two people who live long together tend to grow alike is accounted for by unconscious mimicry reacting upon the muscles of expression in the same way that a ruling passion does. This tendency to facial imitation is very general—in fact, almost universal—and may be so marked as to be easily noticed; so that when two people are engaged in animated conversation, the expression of the listener may often be seen to echo that of the speaker. How "infectious" is a smile or a laugh, even when the idea which gave rise to it in the first case is not transferred!
Several times, when talking to young people, I have suddenly and purposely adopted some change of expression, such as the ​raising of the eyebrows; and this, although not the least apropos to the words spoken at the time, has instantly evoked a like movement on the faces before me. The response was quite involuntary, and was a pure piece of instinctive reflex action. Why does a yawn spread like pestilence through the room when conversation flags? I know of those who have started such an epidemic by a little piece of acting, and not a mouth in the company (save the guilty one) knew why it gaped. Have not we all noticed that a man of marked individuality becomes a center of physical influence to those who wait on his words, so that his gestures, tones of voice, and turns of phrase are reproduced? I know a tutor whose peculiarities of speech and carriage have been adopted more or less by every one of his pupils during the last six years, and several of them have come to resemble him in feature. This unconscious imitation of expression is very noticeable in children. Has it occurred to many careful parents that the good looks of their daughters may depend in no slight degree upon their choice of nurse girls and governesses?
For some reason which we can not fathom, the imitative faculty is so ingrained in us that what the eye perceives the brain makes haste to reproduce without stopping to ask our permission; and where two people live long together the facial muscles of each are constantly receiving stimuli prompting them to mimicry. As in the case of the emotions, these influences may be infinitesimal at any given moment, and may give rise to no visible change of expression. Yet in the course of time they tend to mold the whole countenance, feature for feature, into an almost exact facsimile of another.—Blackwood's Magazine.