It has long been held that increase of comfort increases stature and weight. Quetelet was the first to demonstrate this by comparing the measurements of factory children with those of others more favored. Key concludes that in nearly all lands '' the weak period of development before puberty is lengthened for the poorer children to their cost," and that the prepubescent growth comes later but is more sudden, so that poor and well-to-do children end their growth about the same time. Some infer that boys are more influenced by this than girls, as they seem to be by many other of the factors of environment. Bowditch concluded that the superior size of children of American parentage in the Boston schools is partly due to the greater comfort and partly to race, but thinks the former more potent than the latter. In England, Roberts found that in the better classes, prepubescent growth began a year or two earlier than among laborers, and that the former were more variable in height and at least two inches taller. The anthropometric committee's study in England found that boys from the better classes at ten were 3.31 inches taller and 10.64 pounds heavier than industrial schoolboys, and at fourteen they were 6.65 inches taller and 21.85 pounds 32 THE PSYCHOLOGY OF ADOLESCENCE heavier. In Leipzig, children paying eighteen marks school- fees are superior in height to those paying nine marks, and gym- nasia boys exceed those of the Real and Burger schools for the same reason. The same difference has been found very marked in Russia, Stockholm, and Turin. As Burk well points out, however, the poorer classes from ten to seven- teen, the ages best studied, grow at quite as rapid and often a more rapid rate than those of the favored classes. Their absolute increment may be the same or even greater, but the conditions existed earher and they were already smaller before observation began, so that defective nutrition may have its chief effects in the earher years or even during embry- onic life, but figures are, however, too small to warrant con- clusions for these earliest years. Weight seems at least quite as much if not more affected by social condition than height, although its chief effects are manifested in both after the period of pubertal acceleration.
When we turn to the effects of different kinds of food upon growth, results are difficult of interpretation. Hansen studied in a deaf-mute asylum in Copenhagen the effects of a change of diet, from one consisting chiefly of black bread and beer to one made up of bread and milk and richer in albumen. The seventy boys together gained 105 pounds more under the new diet, but did it all in the six weeks from October eleventh to November twenty-second. All the rest of the six months' growth was unaffected, so that on the whole he thinks food had no effect and he urges that weight is no true index of essential growth. It has also been demonstrated in many cases that poor children brought into a better nutritive environment grow more rapidly than those who remain in unchanged conditions. In Russia, an elaborate experiment on the relative growth of weight in about fifty infants fed exclusively from the breast and those fed artificially, seemed on the whole rather favorable for the latter food, but this may have been because the former was scanty.
That perverse or defective nutrition tends to retard growth and to delay the characteristic growth periods and also that the final size attained is thus reduced, seems also estab- lished with great probability. Excessive functional activity probably has the same tendency, as growth and work, while GROWTH IN HEIGHT AND WEIGHT 33 mutually helpful up to a certain very variable point, become antagonistic beyond it. Disease retards, while health and growth go together. Some seasons make for growth and others for retardation. Combe thinks that boys born be- tween September and February are shorter than those bom between March and August, while girls born from De- cember to May are shorter than those born during other seasons.
Thus we must conceive growth as due to an impulse which, despite its marvelous predeterminations, is exceedingly plas- tic to external influences, a few of which can be demonstrated and more have to be assumed. The Heraclitic fire of life as thus observed is like a sensitive flame burning now high, now low; swerving under various influences; its combustions or oxidizations now faster, now slower; always true to its own laws, but in its rhythms infinitely more delicately responsive to everything in the environment than we have dared to dream. To the inner assimilative and dissimilative processes, which physiological chemistry alone can ever hope to unravel and which underlie all morphologic and perhaps even functional changes, there is strong reason, as we shall see later, to ascribe a susceptibility of incredible fineness, due at bottom to the growth impulse in conflict with the vast variety of obstacles on which it impinges.
The effects of climate, which have been insufliciently studied, are sometimes difficult to separate from those of work and rest. Low temperatures involve kinetic energy to maintain heat, and larger quantities of food must be pro- vided. Its indirect influence in affecting mode of life, food, etc., must be of itself great, while the earlier age of puberty in most warm cHmates would suggest earlier completion of growth. No doubt there is an optimum temperature most favorable to the highest human development and also a limit of variation beyond which retardation is caused. The studies of the effects of temperature upon the growth of lower animal forms are interesting here.^ * See also The Migratory Impulse vs. Love of Home, by L. W. Kline (Am. Jour, of Psy., October, 1898), which shows the inferior stature of the inmates of truant schools, and how low nutrition breeds discontent and the tendency to run away.
4 34 THE PSYCHOLOGY OF ADOLESCENCE In view of all we know of the influences affecting growth, the problem whether ultimate size can be otherwise much controlled, except by avoiding certain known causes of ar- rest, need not concern us. Interesting as it is and despite Han- sen's suggestion above of migration, it may seem to some to lie rather in the realm of some modern analogue of Plato's republic than in that of science. But Boveri found that each half of a fertilized ovum in lower forms produced a complete individual but of half size. Bizzozero, Yung, De Varigny, and others have found that by increasing heat and blood pressure, or- gans of growing animals could be greatly increased in size, and that the ultimate size of snails and tadpoles was increased with the size of the vessel containing them. The results of thyroid feeding; the greater size of plain dwellers as com- pared with their congeners among the hills, and of boys bred in the country over those in the city; all the results which La- marckians claim for use and disuse, and those urged by physical trainers for college youth as the results of judicious exercise; the effects of the misery spots of the world; the increase of size claimed to follow the increased prosperity of a country; the tendency of offspring of mixed races toward the size of the tallest parent; and other facts of this order, suggest hopeful auguries for the future when man shall have more fully domesticated himself in the school of civilization; the home, city, and nation of Hygeia shall become a reality; and also all known principles of human stirpiculture in select- ing partners and in marriage regimen shall be put in practise.
Is the race or are Americans growing? Dr. Anderson, the physical instructor of Yale, thinks that the Yale men of to-day average nearly an inch taller than those of twenty years ago, also that they are heavier and more muscular. Mr. Goldie, for thirty-four years gymnastic director at Princeton, says that thirty years ago the average student was five feet seven or seven and one-half inches tall and weighed about one hundred and forty pounds, whereas to-day the average student measures five feet eight or eight and one-half inches and weighs not less than one hundred and forty-five pounds, and goes so far as to predict that, if this rate of development is maintained, in 1950 the average student will be six feet tall and will weigh one GROWTH IN HEIGHT AND WEIGHT 35 hundred and sixty pounds. Prof. P. C. Phillips, of Amherst, thinks that the young women in our colleges to-day are " almost certainly an inch taller and four or five pounds heavier than they were ten years ago." '' The young man of to-day," he says, " at every age is taller and heavier than the man previ- ous to 1894, the difference as a rule amounting to an inch in height and three pounds in weight." The average height of the American soldier is five feet seven and one-half inches in his stockings. He is both heavier and taller and has larger chest girth than the soldier of any other country save only Scandi- navia. Professor Donath's statistics suggest that in most Euro- pean lands height and weight are slightly decreasing. These opinions we must accept with caution, for not only must meas- urements be very carefully correlated with age, often increas- ing in college, but with the fact that college environment is more and more favorable to growth, and we must also have horqo- geneous classes and races as a basis of comparison. Certainly an inch or even half an inch in twenty years, which would make five, or two and one-half inches per century, is quite incredible. If man has developed from a pigmoid and is still growing, it must be at a vastly slower, and probably with data at hand, an almost insensible rate.
Is a period of rapid growth advantageous or would it be better if the curve of height and weight were a straight line, as, previous to the measurements above described, it had been generally supposed to be? While this question can not be answered, it suggests important theoretical and practical considerations. If there were danger of stagnation or of becoming hidebound on the lower level of ten to twelve years, if an equilibrium within and without were liable to be established here, it is not impossible that there might be physiological advantage in growing part by part or by the method of what is known as nascent periods. If, for instance, the bones grow first and tense the muscles causing growing pains, as often occurs, the latter are thus stimulated to fur- ther growth. If fundamental joints and muscles grow first, then the apparatus of the finer accessory system is stimu- lated to restore the old proportion so that we can act as deftly when we are large as we do when we are small. Fat 3^ THE PSYCHOLOGY OF ADOLESCENCE accumulatiorx often precedes growth in height, especially in girls, as if the body were provisioning for an advance move- ment. Structure and function, body and mind, weight and height, may thus each act as a leverage for the increment of the other, if we assume a tendency always to restore the lost equilibrium, and after a fall, to find at-one-ment on a higher plane. Thus it may be that if we could measure kinetically all the energies of growth, their summation would still be represented by a straight line, and the height and weight aug- mentation be only an accident of our as yet inade- quate knowledge and methods of measuring all the expres- sions of growth. On the other hand, phenomena like acro- megalia and perhaps genius in one direction with defect in others, and many other morbid phenomena, indicate, as we shall see later, that growth may be disequilibrated and become SQ excessive in one part or function that others can not be brought into harmony with it or they may even retrogress be- cause left too far behind in the intersystemic competition for nutriment or power.
Is the utmost possible growth desirable? This presents a vast but hitherto unsolved problem. On the one hand, Bohannon ^ has shown that children who are especially tall or heavy for their age are dressed and treated as if they were older, associate with those more mature, and more is expected of them on account of their size. They are more likely to be leaders, to have undue attention, and are so treated as to bring early maturity. Children unusually small of their age, on the other hand, often associate with and dress like those younger than they, and less is expected, so that retarded development often results. Thus, if Porter's inference, that large children are intellectually superior to small ones, is confirmed, it may be at least partly due to artificial, and not to natural causes, and the popular concep- tion that rapid growth is likely to be attended by sluggish mentality may yet be true to nature.
The Chicago studies of Christopher and Smedley in gen- eral favor Porter's conclusions. Although often the best * Ped. Sem., vol. iv, p. 3 et seq.
GROWTH IN HEIGHT AND WEIGHT 37 pupil in a room is the smallest and perhaps the youngest, these constitute a class by themselves, deserving, like all ex- ceptions, special consideration. Christopher says: *' Such children can not be considered normal, and I venture the assertion that the true explanation of them will be found to be of greater medical than pedagogical interest."
Porter found that children who make the best progress in their studies are on the average larger in girth of chest and width of head than children whose progress is less satisfac- tory. Successful pupils are larger than unsuccessful, but the comparative rate of growth, the age at which increase begins, and the point where girls most exceed boys is about the same for dull, mediocre, and precocious children, at least from seven to sixteen years of age.
Professor Beyer ^ concludes that '' the relationship be- tween physique and mental ability is such that the training of the one will indirectly and favorably influence the growth and development of the other, when the training of either is kept within physiological limits." He supports Porter's con- clusion that " precocious children are heavier and dull chil- dren lighter than the mean child of the same age," against Boas, who states " in fact, an investigation which I have carried on in Toronto with the same object, but according to a different method, gives just the reverse results. The data were compiled by Dr. G. M. West, who found that the chil- dren pronounced by the teacher bright were less favorably developed than those called dull." Beyer ^ examined and marked 76 applicants for positions as navy-yard apprentices, and concluded that for them, weight has great significance in judging the physique of a young person and consequently his capacity for mental work, again supporting Porter's studies of precocity and dulness.
Desirable as generous size is, it has its limits. Large animals move slowly, are inexact, clumsy, with less fine con- trol, so that size often seems at the expense of function. Galton found tall men somewhat less fertile than short men. Giants not only lack vigor of mind, body, or both, but are ^ Jour, of the Boston Soc. of Med. Sciences, April, 1901.
' The Relation between Physique and Mental Work. Jour, of the Boston Med. Soc, February 20, 1900.
38 THE PSYCHOLOGY OF ADOLESCENCE often marked by stigmata of degeneration or reversion, while restricted growth in both the brute and human world often coincides with great activity. It is not demonstrated that the largest brains as such are best, or that large views, great moods, and wide ideas are more natural in large bodies. Size has certainly great natural advantages not only among ani- mals and savages, but among civilized races. It insures a certain natural prestige and authority and awakens in others the necessity of recognizing leadership, favors dominating manners, and inclines to the assumption of superiority and the subordination of others. Large men can put forth more strength absolutely than small men, but whether relatively, is very doubtful. It is a wide-spread opinion among army sur- geons that small, sHght men can endure hardships best; that large, muscular men are more likely to succumb to epidemics and to other diseases; that even slightly undersized, if sound, men are best for hard service. In many, if not most diseases incident to army life, and particularly fevers, large men are sick longer and are more liable to die. On the Greely expe- dition most of the large men died and nearly all the sur- vivors were small. Well-proportioned " doughboys," or raw infantry of middle weight, are said to endure more time work, hunger, heat, and exposure than large athletic men, although the latter may put forth most active energy for a limited time.
Small as well as homely and insignificant men have a special motive to assert themselves functionally to offset their dis- advantages of structure. Large men are more frequently found among natural, self-made pioneers, chiefs, bosses, cap- tains of industry, and perhaps, though neither is demon- strated, experts and 'specialists are on the average smaller and possibly less handsome and well proportioned, frequent as the exceptions are. Small men certainly are apt to be quick in their rhythms, while large men move slowly in mind and body but carry more momentum. On the whole, perhaps we may conclude that in the economy of nature, height and weight much above the average are liable to be bought at too great a cost of function. As Beyer, whose opinion is enti- tled to great weight, writes me, the results of the battle of life " point to the average of the race as being the goal to strive for with regard to growth." On the other hand, as he adds: GROWTH IN HEIGHT AND WEIGHT 39 " If we find the leaders of a race which is on the march to a higher plane of human development to be larger than the average or the fifty column in percentile grades, then the lat- ter acquire a different significance; instead of being the fittest to survive they only do so by virtue of the protection afford- ed them by the superior qualities of the advanced guard, with- out which they would have to retreat with numerical losses. According to this same figure, those below the average would represent that portion of the population that is unable to keep up with the procession owing either to hereditary or accidental causes, and for whom we build hospitals, asylums, sanatoria, etc." Dr. Sargent writes me: " In my opinion, the greatest possible development of body, mind, or ' soul ' is undesirable, inasmuch as neither condition can be attained in man, a composite being, without dwarfing or impairing the condition of the other two. For this reason, to quote your own language, * physical culture should be chiefly directed to building up average dimensions ' of the masses that are in our schools and colleges. By pursuing this method I think the best results may be eventually attained for the race if not for the individual."
In discussing the desirability of maximal growth we must reflect, on the one hand, that if the earlier stages of growth relatively represent what man has in common with animals, and its last stages raise him above them and make him most distinctively human, then this question must be an- swered in the affirmative, because the most perfect individual is the one most completely evolved. Certainly we want all that our heredity entitles us to, and perhaps a little extra for progress or even for selfishness of the Max Stirner type. Indeed, one might ask why man should stop growing at all, and not progress at least slowly to near the end of his life like extinct Saurians; as, indeed, his heart often does. On the other hand, as we have seen giants and monsters become unfer- tile and we are unable to bring at-one-ment between the greatest individual development and the highest interest of the race to which it should be subordinated. Possibly man- kind may sometime learn the secret of progressively harmo- nizing the two. Meanwhile egoism can only say that max- imal growth is desired if it is in every way proportionate and 40 THE PSYCHOLOGY OF ADOLESCENCE harmonious, and if it is chiefly growth of the best tissues, be they reproductive, cerebral, or muscular. To assert that maxi- imal mass growth for the individual or for our race in the future is desirable, would involve the evaluation of all the functions — physical and psychic — that make human life. Al- though growth upward out of the womb of nature is the one miracle of the world and its direction is the only clue to human destiny, yet progress and the highest human evolution may, for aught we know, be carried too far for other greater issues, so that on the whole we are hopelessly agnostic in the pres- ence of this question. If it be found, as Beyer, Galton, and others think, that most of the present leaders of mankind are somewhat above the average height and weight on the percentile scale, so that the large people are bearing the bur- den of the forward march of humanity, it would indeed appear that those below the average size are followers and are some- what sheltered and protected in the wake of these leaders, and if so, then the race is tending slowdy but surely upward in size, and if the reverse be true it is tending downward.
According to current biological conceptions the soma or cells which make up the organs of the body, in contrast with those devoted to reproduction, become specialized for par- ticular purposes, very gradually in the evolutionary processes and, somewhat in proportion as they do so, slowly lose reproductive power. In the mitosis involved in tachygenesis cells continue to divide, but with ever less rejuvenative energy. Even in the child, each cell can produce only a few genera- tions of daughter-cells, and as differentiation and integration proceed, the momentum given to them at impregnation is gradually lost. In old age the body desiccates, specific gravity increases as does low-level connective tissue, and thus death or a corpse of lived-out organs is evolved. Even in maturity, body cells repair lost tissue in man and lost limbs in animals, as they recover from fatigue, etc. All this is in progressive con- trast with the capacity for indefinite reproduction in the lowest forms of life and in the sexual elements in man which are relatively immortal, because these cells continue to multiply by division indefinitely.
From this familiar consideration it follows that in the GROWTH IN HEIGHT AND WEIGHT 4 1 earlier processes of the evolution of the soma there must be many cells which have already acquired some definiteness by departure from the general type, and which although already more or less set apart for particular functions have not entirely lost the germinant expansion of the purely repro- ductive elements, and under certain conditions may revert to it. Many lower forms reassume growth if reproductive activity is checked, while the latter tends to arrest growth. Hard conditions favor early sexual maturity, and overnutri- tion, as is well known, may diminish reproductive vigor. Thus genesis and individuation beyond a certain point are in inverse ratio to each other. Giants and monsters among men and animals have low generative activity, while both precocity and early dissipation are unfavorable for growth. Hence we can insist that there is a sense in which the growth of the soma itself may almost be regarded as a secondary sexual quality, and growth can be conceived in a large way as a product of reproduction, or the latter as a special or primi- tive form of growth. From the flagella up, hunger and love preside over the evolution of the body. Special organs are developed either to reach food, hold it, digest it, etc., or else to reach or hold the female for impregnation or, irradiating more widely, with which to fight for mates or to charm them as by colors, wattles, antlers, plumes, and all the love antics of animal or human courtship. Not only this, but man's pris- tine and deepest psychic instincts are developed primarily to serve the rising generation by providing food, shelter, nurs- ing, education, and instruction; and even the length of life, as Weismann has shown, is so adjusted as to be continued be- yond the age of greatest fertility only just as long, on the average, as is necessary to bring the young to full maturity. Thus not only the form, organs, and functions of the adult, but his term of life is regulated to meet the necessities of repro- duction and of education, which are in a sense a continuum.
Bearing these general considerations in mind, let us now proceed to inquire whether we can ofifer any explanation of the singular but almost universal retardation just before the pubescent outburst of growth, and of the great increment which follows it in the earliest teens. First, all measurements agree, as we have seen, that girls precede boys in the period 42 THE PSYCHOLOGY OF ADOLESCENCE of maximal growth if not in that of retardation just before. No one, to my knowledge, has seriously attempted to account for this interesting and challenging fact. Lange says it is accidental; several have vaguely intimated that it may have been nature's design that the human female, charged with larger functions and organs of reproduction than the male, was intended to be larger than he, as in the case of the queen bee and many other lower forms of life. She is anabolic, and should normally not have only preceded but exceeded man in height and weight through life, but from some un- known cause, this tendency is arrested and man reassumes the lead in the middle teens. This view is purely speculative and we need hardly consider it here, because this would make man an exception to the almost universal law of mammalian life, where the female is inferior in size.
We may, however, look in another direction for an at least hypothetical explanation. If man has developed from an ani- mal stage of existence to savagery, it seems plausible from what we know of primitive races, phallicism, etc., that the female would at first be prematurely impregnated, at least as soon as she became attractive to the other sex, on account of the hypertrophied sex passion in the human male, and would have been forced to assume maternal functions before nature had completed her preparations therefor. Many of the institutions of higher and even of savage life, however, later came in that would tend to postpone fertilization. Thus we should have an early stimulus of the reproductive function followed phyletically by a more or less gradual postponement of it. With this delay, the cell development that had formerly gone to genesis would turn back to individuation, and the vitality that had made the fetus and decidua would now make for somatic growth. On this view, part of the sudden and early increment in girls is a trace of ancient but now deferred maternity due originally to premature male aggression, but now turned to personal augmentation by male restraint and female coyness. This view at least is entirely congruent to, and even favored by the above current biological conceptions, while anthropology is rich in facts that indicate progressive delay of motherhood with emergence from animal to higher human stages.
GROWTH IN HEIGHT AND WEIGHT 43 Natural selection suggests another partial explanation. Sexual desire normally develops progressively to a maximum during years of greatest fertility, while the instincts of female coyness and reserve are strongly developed earlier. Thus the largest and most vigorous girls would be able most suc- cessfully to resist fertilization, even in an age of animal vio- lence, by not only their mates of near their own age of the opposite sex, who were coming to maturity and whom they would see most of, but also especially, if the advantages of the upright position in this respect be also considered, would have increased power to protect their chastity from older males. The weaklings who failed to do so would produce weak, because immature, offspring, while those who were large and strong would transmit this variation to their female chil- dren. Hence this augmentation, which now seems in the course of nature and without any direct advantage of utility, may in the past have performed a very important service for heredity in helping man on to a higher plane of greater ma- turity. The very size, due in part originally to too early maturity, may now be utilized as an instrument to prevent it.