ness later are handicapped in the race of life. Porter well says that the lack of proper relations between height and other physical dimensions is itself ill health. Great height involves increased work for the heart and for the skeletal muscles, and a greater loss of heat, because the surface of the body is larger in tall than in short people of the same weight and bulk. Even on the average, the relation of surface to weight is only about three-eighths in the adult of what it is at birth. The exceptionally tall person, therefore, if not rela- tively developed in other dimensions, although he may have sufBcient income of vitality to meet the demands of life, will fail under strain. Insurance companies discriminate against tall and slender men.
GROWTH IN HEIGHT AND WEIGHT 21 From May, 1882, to February, 1886, Malling-Hansen/ director of the deaf-mute institution at Copenhagen, daily weighed 130 of his boys, and for the last two years of that period, daily measured them with well-elaborated precautions to secure uniformity and accuracy. He found that the weight of an average boy from nine to fifteen passed three annual periods of change. The period of greatest growth was from August to the middle of December. During the second four and one-half months till the end of April, growth was of average rate, and it was least for the next three months ending with July. During the maximal period the daily gain was three times as great as in the middle period, while nearly all the gain of the latter was lost in the minimal period. For growth in height, the minimal period begins in August and lasts till near the end of November, the middle period lasts four months till the end of March, and the maximal period lasts four and one-half months to the middle of August. In the middle period the daily increase is twice, and in the maximal, three times as great as in the minimal period. Boys grow thick most slowly while they are growing tall fastest, and vice versa. Increase in weight varies with local temperature, so that all these changes the author ascribes ultimately to the sun.
According to these conclusions, spring growth in height leads with very slight autumnal increment in thickness, and a year or two later, the latter predominates and the former ceases. During the annual as distinct from the longer peri- odic changes in rate of increase, the season of most rapid growth in height is also the period of least growth in weight, and vice versa. To secure this later thickening of the body to due proportions, so as to prevent the wastes and dangers of tallness and slenderness, is one of the most important desiderata of hygiene and body training. To win back the due proportions between height and thickness and to cor- rect those rarer cases when the converse relation exists, Mal- ling-Hansen suggested that children who are in danger of remaining too short and thick go gradually south to warmer ^ Perioden im Gewicht der Kinder und in der Sonnenwarme. Fragment HI, A. Kopenhagen, 1888, pp. 208. Fragment III, B, Atlas, 44 Taf.
22 THE PSYCHOLOGY OF ADOLESCENCE climates toward the end of summer, when the period of max- imal growth in weight comes, and so be removed from the influence of the maximal period of growth in thickness. Con- versely, a tall, slender child must be removed from the influ- ence of the maximal period of growth in height by being taken slowly north in April. Travel, he suggested, might thus be prescribed to control growth by following spring or autumn, as height or thickness respectively is desired. The practicability of this remains yet to be tested.
Again, adults probably tend to grow thin at the same period when children tend to grow tall, and also to grow thick when children grow heavy. By choosing the former period for cures, fleshy people can aid nature. School vacations should come at the time of the periods of most rapid growth. Even trees grow tall in May and thick in June, resting in one dimension while the other grows. Finally, children eat most in the winter, beginning in December, and reach a maximum in March, when growth in height begins, so that growth does not immediately follow an increase of food-supply.^ Camerer corroborates Hansen's facts of seasonal fluctua- tion, rejecting his cause. Wahl found that Danish children gained in weight during the summer half-year more than during the winter half-year, and that for children below school age there was also a sHght difference in the same direc- tion, which was, however, greatly accentuated at puberty. These conclusions do not quite agree with those of Wretkind, the first in this field, who found that girls over nine, in three Swedish schools, grew in weight relatively more in the three vacation months of summer than they did in the other nine months of the year, and this fact he ascribed to the retarding influences of the school. Vierordt ^ finds weekly or half- ^ Hansen expended vast labor in connection with these studies to establish a curious but now quite discredited theory that growth periods in children, tempera- ture changes in grown women, etc., correspond to a slight periodicity in tempera- ture. This occurrence he thought world-wide and due to the revolutions of the sun every twenty-seven and one-half days, and he constructed an outline of the solar corona of a shape needed for his hypothesis. His own voluminous curves are, how- ever, mostly twenty-five-day periods, while many of them can hardly be distinguished from the lunar periods of twenty-eight days.
2 Physiologic des Kindesalters, von K. Vierordt. Gerhardt's Handbuch der Kinderkrankheiten, vol. i, pp. 228-236.
GROWTH IN HEIGHT AND WEIGHT 23 weekly periods repeating themselves, so that healthy chil- dren are constantly fluctuating.
Many studies show a diminished rate of growth in both height and weight during a few years preceding adolescence. In general, the decrease begins at six or seven and continues with various oscillations until about ten in girls and twelve in boys. Various observers find a period ending at the sev- enth or eighth year, when the brain has about ceased to grow in weight. Peckham and Vierordt make this age, which about coincides with second dentition, a period by itself. Up to its close, despite the fluctuations, there is relative uniformity of rate, and boys and girls differ but little. West found this age of retarded growth rather uniform, but thought the great diversities that begin with pubescent growth due to heredity and environment. Nearly all the best researches reveal this diminished rate of growth in height and also in weight. Even although the absolute increment is maintained during these minimal years, the percentage rate is usually diminished. The same retardation is also manifest in nearly all returns for weight, although it can not be determined whether height or weight have precedence in this retardation, and this holds for individual as well as mass measurements.
Vierordt thought he discriminated seven growth periods; Liharzik/ twenty-four; Zeissing, three; Cohn, two; Key and Lange, four. On Minot's assumption of senescence as a con- stantly incre-ising arrest of growth culminating in degenera- tion, these rhythms may be conceived as oscillations between two opposing tendencies. This author does not use his hypoth- esis, how^ever, to account for rhythms, nor is there ground to urge that retarded growth at ten or eleven suggests senescence so much as a diversion of growth energy from other fields. It is a little as if the processes of assimilation made a sudden ad- vance, extending their conquest over non-living substance, and then paused to organize the new acquisition; or else, if it be es- tablished that periods of increased food consumption precede growth increments by a considerable period, as if the ashes and cinders of the biological furnace are first removed with exceptional thoroughness to prepare for the extension of life's * Das Gesetz des Wachstums und der Bau des Menschen, etc. Vienna, 1862.
24 THE PSYCHOLOGY OF ADOLESCENCE combustion to new fuel, so that vitality is first thus raised to a higher level, itself an expensive process, and then the mass it animates is augmented. This is different from the decay of old age, when many cells die from overspecialization, in that it is not compensated and it also is arrest at the bottom rather than at the top of the scale of complexity. Even in the segmentation of the ovum, there is a rhythm of fast and slow and a marked oscillation about the sixth fetal month. Pauses may be to permit adaptation of new-grown cells, tis- sues, or organs to each other and to the environment. That the amount and time of retardation is exactly compensated during periods of augmentation is a theory that at present lacks confirmation, approximate as this may be for normal individuals. Moreover, there seem to be norms of rates and seasons of growth from which organisms can only with diffi- culty be much diverted without distinct compensatory tenden- cies. As in convalescence not only lost flesh but growth is often made up, so hardship, malnutrition, etc., may retard for a time, only to be followed by compensatory acceleration, all the more rapid if the delay has been prolonged up to a certain point, a point probably itself variable. As to whether causes that result in excessive and premature growth tend to react in stationary periods, the evidence is less clear. We also often see what seems to be an illustration of the law laid down by St. Hilaire, that growth in size and in function are inversely to each other, so that when either is progressing rapidly the other tends to be stationary, and the alterations here are often rhythmic, like those between growth in size and in weight.
Will retarded growth be made up or compensated for later? Key thinks that where children grow slowly owing to hard conditions during their earlier years, they will catch up later and end their growth with others who have been more favored. All who have weighed and measured large numbers in such a way that their results bear on this ques- tion, indicate, as we have seen, a certain elastic resilient tend- ency, at least to resume, if not to complete, interrupted or delayed growth, somewhat as the emaciation of disease is compensated. There is reason to believe that weight gained GROWTH IN HEIGHT AND WEIGHT 2$ near the normal period for its most rapid increment is more likely to be retained permanently, especially if the muscles are mainly concerned, than if it is won later. We should infer that growth was most advantageous when it was most timely and when the latent energy of tissue-producing power was normal. The opinion which some have held that where one or even several generations have been kept down by hardship, their descendants tend to regain the former height of their race if conditions become favorable, rests on too slight evidence, and indeed seems to have been suggested by the phenomena of alternation of generations.
Concerning the later stages of growth, the data are insuf- ficient and opinions are contradictory. Quetelet, influenced again, no doubt, in part by his mathematical formulae of growth, thought both sexes might continue to grow a little in height till twenty-five, and in weight till perhaps thirty. Liharzik thought growth continued in both sexes till twenty- four or twenty-five, Villerme till twenty-three. Zeissing thinks twenty-one is the time of cessation in growth of both sexes. Venn finds moderate growth in height in male stu- dents at Cambridge, England, up to twenty-three, and in weight to twenty-four. Hall finds that boys drop to a very slow rate of increase in height at eighteen, but continue to grow at about that rate for three years; and that in weight, their rate of increase is retarded from eighteen to twenty and then starts up again. The Anthropological Committee concludes that after a retardation at eighteen, boys increase in weight at nineteen or twenty and continue to grow till twenty-three or twenty-four, and that girls pause at nine- teen without entirely ceasing to grow, but go on a little more at twenty or twenty-one. Key finds not an entire cessation of growth, but a distinct retardation in weight and height at eighteen or nineteen, with indication of later increment.
Roberts asserts an " entire cessation " of growth in the non- laboring classes of England at nineteen, but thinks in the artisan class, growth is more uniform and extends to the twenty-third year. Smedley ^ found that girls grew in height at * Report of the Department of Child Study and Pedagogic Investigation. Chicago, No.?, 26 THE PSYCHOLOGY OF ADOLESCENCE a rather uniform but reduced rate from fourteen to seventeen, when they had practically attained their highest stature, and that from just before nineteen until after they were twenty, boys did not grow in height. Beyer thinks that the naval cadets at Annapolis for thirty years show an almost steady increase in weight from fifteen to twenty- three, amounting in all to thirty- seven pounds, and that growth in height shows marked retarda- tion at eighteen; that then comes another increase, closing at twenty-one, and later a third increase, ending perhaps with growth of span of arms at twenty-three. He also infers that tall boys complete their growth earlier than short boys, but that tall and heavy boys are more likely to increase under the influence of gymnastics than those that are small, and that the ratio of increase in height and girth is different in these two classes. Lange thinks there may normally be an infin- itesimal growth till senescence, and that it tapers off asym- ptotically, and one writer conjectures that by this increment, civilized man is slowly growing larger, and that we should so live as to keep on growing till the age of forty-nine, when Plato thought man attained his highest development. Early Amherst reports showed that students, as a rule, do not grow in height from eighteen to nineteen, but that some increase up to twenty-five. Several of the best American colleges report cases of growth of from one-third of an inch to a little over one inch in half a year after eighteen, a result that is ascribed to physical training. Large boys seem not only to achieve their adolescent growth earlier than small ones, but are more likely to keep on growing.
Dr. Edward Hitchcock, who still measures Amherst stu- dents and has made many reports, while admitting the meager- ness of his numbers for the later years of growth, writes me: "I can only say that growth, in our observations, continues up to twenty-six years of age, whether longer or not our data do not show." Beyer, perhaps our most competent au- thority upon this point, writes me that in a list of height averages based upon 8,000 accepted recruits, it appears that while there is no increase from twenty-four to twenty-five (nearest birthday), there is an increment of one-tenth of an inch at the twenty-sixth year, but that the height then attained is not exceeded by any age up to thirty-five, which is as far as GROWTH IN HEIGHT AND WEIGHT 27 his work has been carried. He says we know '' that exercise has been followed by a very slight increase in height in some rare instances at a late period in life," and suggests that, if poor personal hygiene or bad conditions prevented men from attaining predestined height during the usual periods of growth, the change to more favorable influences '' may cause a reawakening of dormant, undeveloped centers and in this manner aid nature in making up for lost opportunities at a later period than is usual."
Dr. D. A. Sargent, of Harvard, whose data pubHshed and unpublished are of the highest value, writes: ** Men usually cease growing in height at about twenty-three, but continue to increase in weight up to fifty. It is a question, however, whether most of the weight accumulated after twenty-five is not more or less abnormal. It may be, however, that this is nature's way of conserving the body's heat and storing up excessive carbon to meet the demands of advancing age."
Prof. J. W. Seaver writes me that from his data based on Yale men he can " not find an age when there is not a small increment in height or weight, although this is very small after twenty-three years of age. The growth curves of the mass taper ofif gradually, but those of individuals nearly all show spasmodic growth. As the periods of growth and rest come at irregular intervals in different individuals, I think they tend to neutralize each other in the mass. Persons taking the least exercise grow least, but the opposite is only partially true. The athletes grow more than ' high stand ' men taking certain severer courses that are confining in their nature. These show slight or no average growth, the slight gain in the few being neutralized by the loss in the others."
From data and opinions so diverse, no inferences of scien- tific validity can be drawn, and we have little settled knowl- edge of the laws of growth after eighteen. That there is a general retardation about this age is probable. That there is a later upward tendency in weight in boys can hardly be doubted, and the same is probable to a much less extent in height. Growth seems also to have a far wider range of indi- vidual variation as its momentum diminishes near its ter- minal stages, than earlier in life. It is not unlikely, too, that as a spent ball is more easily stopped or turned, so the 28 THE PSYCHOLOGY OF ADOLESCENCE later stages of growth are more easily prevented by improper diet or hygienic conditions, excess or defect of exercise, ex- citement, overpressure in school, vice, or possibly they are transformed into some kinetic equivalent of function, reproduc- tive, motor, or assimilative, etc.
It is hard to realize the complexity of processes involved in the term growth, and yet there is a point beyond which oversubtle methods of weighing and even measuring are mere pedantries. If a child lived in a glass case on the arm of a sensitive balance, and every respiration and all its insen- sible perspiration, as well as all food and secretions, could be weighed, measured, and chemically analyzed with the utmost accuracy, tentative determinations already made in this direction show that we might be able to estimate to an extent as yet by no means attained, how much loss of each kind was caused by emotional strain or by mental activity, and just when and under what functional and other condi- tions, growth occurred. But even this interesting physical biography could never tell us what organs were growing large or heavy, or what, if any, small, or which took up and vitalized the ingesta, and in which loss exceeded profit in the chemical bookkeeping of metaboHsm. The body contains matter in all degrees of organic assimilation, from food just taken and excrement, up to the most controlling parts of the cells in the highest tissues. Cell nuclei or nucleoli, leuco- cytes, or other invisible and hypothetical chemical compo- nents, perhaps brain-cells or the reproductive elements, or whatever else may be thought to be at the high-water mark of organization, and so most vitalized and dynamic, represent a very different level of life and are perhaps as much above simple and lower structures, like bone and connective tissue, as these are above fat, or fat itself above the chip pile of products of decomposition awaiting removal. Individuals differ im- measurably in their nutritive plane; and water and fat, urea and other low-level and waste products may accumulate by reason of imperfect elimination. Growth is really the forma- tion of new cells, the development of cells from granules or, as is more common near the end of the growth period, the further increase in size of cells already well developed. It GROWTH IN HEIGHT AND WEIGHT 29 is these processes that are chiefly sought, and other factors included in growth in weight are not true growth but, in a sense and in varying degrees, errors to be overcome.
Of what actually goes on in the body, then, we know relatively little. No admittance is, as some one has said, the sign which nature hangs out to the physiologist. Could we weigh or measure the gain or loss on any of its higher planes, we might find very different laws of growth. We may conceive our ego as limited by the dermal surface and as scarcely even perforated by the twenty-two foot alimentary canal. We can not say just when the food we take becomes no longer a for- eign substance to be acted on, but part of the true physical self, and endowed itself with assimilative power, nor can we say when tissues on the down road of decay cease to be so, any more than the psychologist can tell when the matter of apperception becomes an organ of it. The suggestion is obvious, how- ever, that seasons of rest between growth periods may be times of the greatest qualitative improvement, when what we may call the higher digestion augments the complexity of structure and assimilative processes are carried on upon a higher plane, and all by the same growth impulse as its kinetic equivalent of augmentation in bulk. Of such changes, how- ever extensive or important, determinations of the mass of the body as a whole can give no intimation. Of the laws and processes of growth in individual tissues and organs, our knowledge is but Hmited, and of those in chemical com- plexity, we know still less, and yet it is not improbable that these more specific and higher changes are more closely re- lated to psychic development than is growth in height and weight. Mass, cytological change, and chemical complexity and functions, then^ are the three factors or dimensions of growth, and many of the mysteries in which it is now shroud- ed will remain unsolved till we know more of the last two and of their relations. Studies of fatigue and all we know of metabolism indicate that the second factor is far more vari- able, especially within short periods, than mass, as well as far more closely associated with function.
The rate of growth is a result of many determinants. Race and heredity seem to decree for every individual being 30 THE PSYCHOLOGY OF ADOLESCENCE an approximate ultimate size, and the way in which total growth is distributed over the years in which it occurs, is one of the most characteristic expressions of heredity. This seems to prescribe and ordain almost with an aspect of fatality, as if every person and part strove to attain a certain size decreed by ancestral ids and determinants, which, although due to a less fundamental momentum than that which determines the species, is hard to modify much by training or even environ- ment. In this factor many anthropologists are chiefly inter- ested and many general and special anthropometric inquiries are undertaken in quest of purer and more aboriginal race types. The Patagonians, the North American Indians, espe- cially the Mississippi tribes, and the Scotch are perhaps the tallest, with Swedes, Norwegians, and white Americans as close seconds; while the African dwarfs, Japanese, Eskimos, South Italians, Bushmen, West Africans, Malays, French, and Spaniards are among the shortest races of men. So far as we know not only after, but before puberty these relations are tolerably maintained. Next at least to hair and eyes, stature is thought to be fundamentally determined by race. Women more nearly attain the stature of men among savages than among civilized races, a fact against the theory of pro- gressive equalization of the sexes. Natural as distinct from forced emigrants, Ripley ^ thinks taller than the " stay-at- homes." Long-headed or dolichocephalic races are taller than brachycephalic or broad-headed races, and the former seem to have been on the whole represented by the more energetic and civilized peoples, and, some anthropologists add, are characterized by more vigor of limb and energy of action. While city life tends to shorten stature, the city is fed by the tallest youth from the country. Most of the human race are between five feet and five feet ten inches, so that with all the causes of variation, the human species is quite uniform as compared with many animal types. According to Bowditch, American boys are taller and heavier than English boys of the non-laboring classes in public schools and universities, the superiority being somewhat greater in weight than in height. He also found that the greater height and weight of Amer- * Racial Geography of Europe. New York, 1900.
GROWTH IN HEIGHT AND WEIGHT 3^ ican over Irish children was due more to race than to occu- pation. Incidentally Peckham found that urban life tends to decrease stature and that intermarriages between Germans and Americans were advantageous because children tend to reach the height of the tallest parent.
While American boys are taller and heavier than others during pubescent years they excel only for a few years, and at nineteen are overtaken and surpassed by Swedish, Danish, and Dutch boys, while Belgian boys and those of northern Italy remain the smallest of those whose growth has been carefully studied. In the same way, Swedish girls excel those of other nationalities, both in height and weight, except dur- ing a few pubescent years. Key thinks for both sexes and in both height and weight, growth ceases earlier in Italy and America than elsewhere. Retardation by poverty is most marked in Italy and England, and least so in the United States. Racial influences upon both weight and height seem to assert themselves strongly at puberty.