Median age

“ In the first place, the average deviation of the median Binet ages from the life ages at each year is 6 months; second, the average deviation of the median block-design ages from the life ages at each year is 8.8 months; third, the average deviation between the two intelligence-test medians is 8 1/2 months, and finally, the arithmetic mean of the two medians for each life age results in a more accurate approximation of what may be the 'true' mental age than either median taken alone. The significance of the last fact will have to be left for more complete discussion in the later monograph. ”

“ The first striking thing to be observed in Table III. is the fact that the average age is a few months higher than the median throughout in the totals of all colleges. In the past fifty years, the average age of graduation has remained quite unchanged, while in the past forty years, the average has fallen one and a half months. ”

“ The people who lived to be old represented the disease-resistant strain of their generation and on account of their superior fecundity this quality is distributed largely throughout the population. “A very large proportion of each generation is sprung from a very small proportion of the preceding generation; namely, from the people who lived to old age. The members of the short-lived group come from the short-lived parents. The children of the long-lived parents are on the average stronger, more vigorous, and longer-lived than the children of others, and there were more of them per family.” ”

“ By the aid of the “English Life Table No. 3” it was ascertained that in a population resulting from births increasing at 1 per cent. per annum, the following numbers would represent the proportions of persons living and dying at high ages:—
From the above table it may be deduced that, supposing persons aged 71–75 call themselves (or are described as being) on an average six months older than their true age, and if after 75 the exaggeration averages an entire year, a very great impression must be thereby made upon the returns. ”

“ Again, we have made great progress along another line, namely, in distinguishing physiological and especially psychological from chronological age, but here we have little consensus of either method or result beyond the early teens. Yet no observer of life can fail to doubt that there is the same and perhaps even, on the whole, greater average diversity among individuals in mental age as they advance along the scale of years. ”

“ As to the length of the working life, from 15 to 65, out of every one thousand males living at the age of 15, 440 will survive to the age of 65, while the rest will have fallen out for some cause. So society has lost more than half its working force at the end of the working period. In the 16th century the average length of life he estimates at 21.2 years ”

“ For another group of five hundred, an average life-span of nearly sixty-five years was found, as against a life-span of fifty-one years for all classes of people who pass the age of twenty. In the case of still another group, studied by a third investigator, an average of seventy-one years was established. ”

“ And if you consult the table when you are seventy-nine you’ll see you have an average chance of living four and three fourths years longer, which will make you eighty-four years and three months old. And when you are eighty-four the table says you still have an average expectation of living three years longer. That ought to be almost long enough for anybody, I should think, but even when you reach the rather mature age of eighty-seven, there’s no need of celebrating your birthday with a grouch, because the table gives the eighty-seven-year-old boys an average of two and one sixth years more. ”

“ Young people wore the same expression as those of riper years, and even extreme youth had something ashen grey in the complexion, something that was like a breath of mildew, unpalpable, deceptive, as of premature old age. In the north everybody looks about as old as he is, not only according to the fixed sum of his years, but also according to the varying life-limit which is determined by a person’s vitality. There we have old and young and middle-aged. But here the majority are neither old nor young, and for the women there is no middle age. ”

“ They are said to manifest the symptoms of old age at 40, and very seldom to live to be over 55 or 60 years of age.
[246-3] Necker, De l'Administration des Finances de la France, 1784, I, 205 ff., gives for 1771-80 the average number of births, per annum, 940,935; of deaths, 818,391; the population at 24,229,000. ”

“ According to a table we have calculated for fifteen countries of Europe, more women than men attain an extreme old age, and the difference increases with the age. The greatest number of persons over sixty years of age is found in France, but not the greatest number of centenarians. Calculating upon the given age at death, we have found the percentage of those among the deceased who were ninety years old and more to be, in Great Britain, 9·73 ”

“ The real question, then, is, How does the longevity of this select class of thirty-seven-year-old men compare with that of more ordinary individuals? The answer is given by the expectation of life at thirty-seven years, which is twenty-nine years, making the average age at death sixty-six years. And this is precisely the age at death of these sixty great men; showing that, as a class (for these sixty may be considered a fair sample) great men are not distinguished by longevity from other men. ”

“ According to the census of the United States not one man in twenty thousand attains the age of one hundred years. If we figure out carefully from [Pg 31] these statistics, we find the average is only about one-third of this period of life. ”

“ Thus, in the majority of the civilised states of Europe, about 30 per cent. of the population consists of those under 15 years of age; but in France, where the birth-rate is exceptionally low, those under 15 years of age comprise a much smaller proportion of the total population.
In the country districts, the age-class of the children and the age-class of the old both contain proportionately larger numbers than the same age-classes in the towns. In the large towns and the manufacturing districts, there is an especially large proportion of persons of about 20 years of age. ”

“ If we compare the ages at entering college with the relative improvement or deterioration in health, we reach the same result. Of those who entered college at sixteen years or under, 28 per cent fell off in health, while 17 per cent gained. The figures for those of twenty and over show an almost exact reversal of these percentages, being 18 per cent loss and 28·5 per cent gain. The problem of age is thus seen to be an exceedingly important one. ”

“ In all ages since civilization began we have frequent outcrops of the tendency to divide human life into stages, many or few, more or less sharply marked off one from the other. L. Löw has given us a comprehensive survey of this subject. There has never been, however, any general agreement as to these age demarcations save two, namely, the beginning and the end of sex life, which divides life into three stages. Child life, as we all know, has lately been divided into various epochs—the nursling; the pre-school age; the quadrennium from eight to twelve; puberty; the age of attaining majority ”

“ As we grow old we see that nothing, after all, matters as much as we had thought. Smith finds comfort in the fact that, according to the census of 1900, one in every two hundred becomes an octogenarian and that out of a population of 36,800,000 there were 176,571 reputed to be 80 years of age or over. ”

“ Because of its impossibility, as far as the rural districts are concerned, it might be well to divide the years from twelve to eighteen into three standards—twelve to fourteen, fourteen to sixteen, and sixteen to eighteen. The age grouping, however, will never be reliable in achieving results, as the individual physical development varies so much. ”

“ Neither the minds nor the bodies of young men are equal to the responsibilities of this, or indeed of any other profession or occupation, at 20, and rarely at 25. Nothing is more evident than that young men, generally, are losers in the end, both in a pecuniary point of view and in regard to health, by commencing business before 30 years of age. ”

“ Marked mental changes now occur, and the generative functions are perfected. Youth terminates at the age of legal majority, twenty-one years, or perhaps the period ought to be extended to twenty-five years of age, as it is with some nations. ”

“ Insurance companies and benefit societies keep close watch of their members and they report that a person ten years old may now count on living to be sixty years of age. That is the average age, whereas a hundred years ago the average expectation [Pg 271] of life at that age was only fifty-three years. ”

“ As everywhere, so here, too, the physical may be called in a sense regulative rather than constitutive. It is therefore not surprising that statistics show that far more conversions, proportionately, take place during the adolescent period, which does not normally end before the age of twenty-four or five, than during any other period of equal length. ”

“ Zeitschr., 1861, 348 ff.) But the inference which may be drawn from a high or a low average of life is altogether ambiguous. A high average may as well be produced by a great mortality among children as by a favorable mortality among those of mature age; and a low average as well by a relatively small number of births as by a relatively short duration of life. (Meyer, loc. cit., 23, 24.) ”

“ Let us glance briefly at the public and private provisions in different lands for the care of the aged, another large topic with a literature of its own. Here, too, we find great diversity of method and theory which it would be premature to attempt to harmonize. Indeed, so limited is our present knowledge of old age that the available data here also open rather than close most of the great questions about it, although we do seem to be at the beginning of a new era regarding this stage of life. ”

“ I believe that the average of the age of the boys in the college classes is but a few months older than it proved to be then. But I am disposed to think that in the prehistoric days there came in more grown men—rather sporadic instances, indeed, but still a good many of them—and that the presence of these grown men in the classes raised the statistics of average of those periods. ”

“ American experience in tables of mortality shows that of 100 persons at the age of 20, 53 will reach 65; 12, 70; at which time the average expectation of life will be 81⁄2 years. If we take 100 people at the age of 30, 53 will live to 65; 48 to 70. But this table was compiled half a century ago, although it is still used—to the great profit of insurance companies as expectation has greatly increased. Ten to fifteen years of life over sixty-five are assured to more than half all wage workers. ”

“ Among other immediate results of this measure, the average age of many thousands of employés has been reduced to twenty-eight years, and the standard of their physical strength and activity perceptibly advanced, to the company's obvious gain and the lessening of the liabilities of the relief association, which were predicated upon the average age and health of the company's employés when the average of age was much higher and their standard of health lower than now. ”

“ He has scientifically demonstrated with accepted studies that a qualitative life span up to at least 115 years of age is reasonably attainable by the average person if they start working on it no later than about 50 years of age, though earlier is much better. ”

“ If the actuary of an insurance office infers from his tables that among a hundred persons now living of a particular age, five on the average will attain the age of seventy, his inference is legitimate, not for the simple reason that this is the proportion who have lived till seventy in times past, but because the fact of their having so lived shows that this is the proportion existing, at that place and time, between the causes which prolong life to the age of seventy and those tending to bring it to an earlier close. ”

“ I have done so in the case of a small group of ten eminent men on my list, dying between the fourth and the end of the thirteenth centuries—including, I believe, nearly all those in my list of whose dates we have fairly definite information during this period—and I find that their average age is exactly seventy-four years. ”

“ Arranging the several districts of the metropolis, in the order of the average age of deaths, we find the average age of the living decrease with the average age of the dying; and the proportion of births to the population increase with the decrease of the average age of death. ”

“ Of course there are always variations; every child will be better at some kinds of tests than at others. But by having a wide variety, and taking the average, you establish a "mental age" for the child—which may be widely different from its physical age. ”

“ In the first place, taking twenty-one years as the epoch of maturity, all the property of a nation, real and personal, is always in the possession of persons above that age. It is then necessary to know, as a datum of calculation, the average of years which persons above that age will live. I take this average to be about thirty years, for though many persons will live forty, fifty, or sixty years after the age of twenty-one years, others will die much sooner, and some in every year of that time. ”

“ We are of opinion, then, that Youth is completed in the forty-fifth year.
And as Adolescence is in the twenty-five years which proceed mounting upwards to Youth: so the descent, that is, Old Age, is an equal amount of time which succeeds to Youth; and thus Old Age terminates in the seventieth year. ”