Opening
THE POPULATION PROBLEM =A Study in= HUMAN EVOLUTION
BY
A. M. CARR-SAUNDERS
OXFORD AT THE CLARENDON PRESS 1922
OXFORD UNIVERSITY PRESS
London Edinburgh Glasgow Copenhagen New York Toronto Melbourne Cape Town Bombay Calcutta Madras Shanghai
HUMPHREY MILFORD
Publisher to the University
Preface
Many different questions connected with population are frequently discussed at the present day. This book is designed not so much as a contribution to the study of any one of these questions in particular as an attempt to trace back to their origin the main problems which now attract attention and to indicate their relation one to the other—to view the whole problem in fact from an historical and evolutionary standpoint. The book is an accident of the war. When war broke out I was engaged in collecting material which is incorporated in this book with the object of discussing certain aspects of the population problem. It had occurred to me that I might write an introduction showing how these aspects are related to the problem as a whole. Further than that I had not gone when there followed five years of active service during which the project of writing an introductory sketch became converted into the far more ambitious project of treating at some length the population problem as a whole. Had it thus not been for these years during which it was possible only to elaborate schemes for future work, I should never have embarked on so ambitious a task. The task is not an easy one, involving as it does both difficulties of proportion and difficulties arising from the necessity of touching upon biological, anthropological and economic problems, with regard to all of which no one man can pretend to have extensive knowledge. Nevertheless, quite apart from the question as to whether this book does in any measure achieve its purpose, those best acquainted with modern population literature will probably agree that there is room for an attempt to view the whole population problem in historical perspective. If therefore this book does no more than draw the attention of those interested in particular aspects of the matter to the necessity of so doing, it will not altogether have failed of its purpose.
I wish to express my very great obligations to Professor L. T. Hobhouse, who read through the whole book in manuscript and furnished me with numerous most valuable suggestions and criticisms. To Mr. Julian Huxley, who read the chapters which deal most directly with biological problems, I am also indebted for valuable help. The calculations which appear in the last section of the fifth chapter I owe to Mr. H. T. Tizard.
I. PAGE
HISTORICAL 17
(1) Problems of population fall under two headings—quantitative and qualitative; the former have long attracted attention; the latter have, until recently, only sporadically aroused interest. (2) Numbers were discussed in a restricted sense in Greece and Rome, but it was not until the sixteenth century (3) that quantitative problems were considered from a modern point of view when (4) a dense population was generally held to be advantageous. (5) This view was not everywhere accepted, and (6) the relation between numbers and the food-supply was from time to time discussed, and the position of Malthus more or less anticipated. (7) In 1798 Malthus published his book, which (8) was favourably received. (9) Neomalthusian propaganda, though not approved by Malthus, began early. (10) Darwin and Wallace were influenced by Malthus in founding the hypothesis of natural selection, and from 1858 onwards qualitative problems have come to assume an equally important place.
Chapter II
THE BASIS OF THE POPULATION PROBLEM: (1) THE QUANTITATIVE ASPECT 37
(1) The ancestors of man were once subject to the conditions prevailing among species in a state of nature. These conditions are studied. (2) Reproduction, the necessity for which can be explained, (3) always consists in the fusion of two gametes, but (4) is accomplished by different methods. (5) Whatever the method, most ripe ova are fertilized, though among lower forms failures may not be infrequent. A reference to the nature of (6) reflex action, (7) instinct, (8) intelligence, and (9) reason shows that, (10) whatever the stage of mental evolution reached among species in a state of nature, reproduction is essentially ‘mechanical’. (11) The vast number of ova (12) is only partially called for by the fact that a certain proportion only is fertilized. The vast number is necessary because (13) owing to the interdependence of all species a large proportion of the young of (14) both animals (15) and plants perish before maturity (16) and is determined by the sum of the dangers to which the young are exposed.
Chapter III
THE BASIS OF THE POPULATION PROBLEM: (2) THE QUALITATIVE ASPECT 64
(1) In the chromatin of the nucleus we have apparently to recognize the physical basis of the inherited qualities which (2) take the form of predispositions towards the development of certain characters. (3) Difference between modifications and mutations. (4) ‘Pure Line’ and (5) Mendelian investigations indicate nature and behaviour of latter on crossing. (6) Germinal change consists in the apparent addition, dropping out, or modification of ‘factors’, the causes of which (7) are unknown, and are not due to the inheritance of acquired characters. (8) Owing to the death-rate being selective, different germinal constitutions are differently favoured, and thus (9) permanent change among species in a state of nature comes about.
Chapter IV
THE POPULATION PROBLEM AMONG MEN 80
(1) The population problem among men has, owing to the evolution of reason, assumed in both aspects a wholly different form. (2) To follow the nature, causes, and results of these changes a sketch is required of human evolution—especially of social evolution. History only provides a partial record for a few thousand years, and (3) we are thus dependent for social history upon our knowledge of primitive races which may be applied to prehistoric races. (4) Outline of future chapters.
Chapter V
HUMAN FECUNDITY 88
(1) We have to ask whether human fecundity has changed and what the effect of certain customs is upon fecundity. (2) It is not to factors influencing the male (3) but to factors influencing the female that we have to look. (4) The length of the mature period increases with good conditions; (5) the interval between births has decreased in mankind, (6) while the number at a birth has probably increased (7) owing to good conditions. (8) That human fecundity has increased is supported by other evidence, (9) including the number of children, and (10) was held by Darwin and others. (11) Polygamy has had no influence, but lactation, age at marriage, early intercourse, and development of fat adversely affect fecundity. (12) Calculations of possible increase.
Chapter VI
HUMAN HISTORY 106
(1) The outline of human history can be roughly dated by (2) estimating the length of the geological eras. (3) Little is known as to the evolution of the Primate stock, but (4) the association of geological data, fossils, and cultural data give a table of human history. (5) Fossil remains of man before the fourth glacial epoch. (6) Neanderthal man in the fourth glacial epoch. (7) Numerous remains in the post-glacial epoch. (8) Putting aside eoliths, (9) we have Lower, Middle, and Upper Palaeolithic cultures, followed by (10) Neolithic culture and (11) the age of metals. (12) Putting together fossil and cultural evidence, we reach a scheme the details of which can be filled in by (13) our knowledge of existing primitive races with (14) certain reservations.
Chapter VII
HUNTING AND FISHING RACES 135
(1) A survey of these races is undertaken to show the prevalence of factors bearing upon fertility and elimination, and evidence of (2) pre-puberty intercourse, (3) prolonged lactation, (4) initiation ceremonies, (5) postponement of marriage, and (6) abstention from intercourse is given. (7) Evidence of small average size of family. (8) Among factors of elimination, abortion, (9) infanticide, (10) warfare, (11) feuds, (12) killing of old and sick, (13, 14) disease, and (15) child mortality are investigated.
Chapter VIII
PRIMITIVE AGRICULTURAL RACES 162
(1) A similar survey of these races is undertaken, and evidence is given regarding the prevalence in America (2) of pre-puberty intercourse, (3) postponement of marriage, (4) prolonged lactation, (5) abstention from intercourse, (6) small size of the family, (7) abortion, (8) infanticide, (9) war, (10) feuds, (11) disease, (12) and child mortality. (13) In Africa similarly regarding pre-puberty intercourse, (14) lactation, (15) marriage, (16) abstention from intercourse, (17) contraceptive methods, (18) size of family, (19) abortion, (20) infanticide, (21) warfare, (22) feuds, (23) disease, (24) and child mortality. (25) In Oceania regarding pre-puberty intercourse, (26) lactation, (27) marriage, (28) abstention from intercourse, (29) contraceptive practices, (30) size of family, (31) abortion, (32) infanticide, (33) warfare, (34) feuds, (35) and child mortality. (36) In Asia of the same practices.
Chapter IX
THE REGULATION OF NUMBERS AMONG PRIMITIVE RACES 197
(1) The theory of Malthus has long been disproved, and (2) has been replaced by the modern theory of an optimum density of population. (3) Territories are strictly defined among hunting and fishing races, and (4) among primitive agricultural races. (5) Among all these races there is co-operation in the search for food. (6) The principle of the optimum number holds good for all of them, and by the natural selection of customs, practices restrictive of increase come everywhere into use in the shape of abstention from intercourse, abortion, and infanticide. (7) Evidence of these practices is incomplete, (8) but shows that they are so practised as to keep numbers down to a certain level, (9) and, though they may be adjusted solely by natural selection, yet some semi-conscious adjustment may take place. (10) That adjustment should take place, a certain standard of skill is necessary on the part of those who set up new families and is ensured by marriage customs. (11) General conditions of savage life afford evidence that customs are effective. (12) There is no correlation between these practices and economic stages; though evidence is lacking, the presumption is that some such practices were everywhere in use (13) not only among primitive but also among prehistoric races, (14) who have moved slowly away from the conditions prevalent in the intermediate stage.
Chapter X
HISTORICAL RACES 243
(1) These races fall under four sub-headings. For all of them the evidence is discussed concerning (2) disease, (3) warfare, (4) and child mortality. (5) In sub-groups 1 and 2 celibacy and postponement of marriage, (6) pre-puberty marriage, (7) lactation, (8) restraint from intercourse, (9) contraceptive practices, (10) size of family, (11) abortion, (12) and infanticide. (13) In sub-groups 3 and 4 pre-puberty intercourse and lactation, (14) celibacy and marriage, (15) contraceptive practices, (16) abortion and infanticide, (17) and venereal disease.
Chapter XI
THE REGULATION OF NUMBERS AMONG HISTORICAL RACES 270
(1) Among these races, in spite of certain complications, the principle of the optimum number holds good. (2) The evidence for the first sub-group is too scanty to base conclusions upon. (3) Among the races of the second sub-group we see how the pressure is felt, and (4) we have knowledge of the factors at work, but (5) in India, China, and Egypt there is evidence that the factors are not effective, and that over-population occurs. (6) In the third sub-group, where the factors are different, (7) we can see in disabilities placed upon serfs, and (8) in difficulties, (9) restrictions, and (10) Poor Law provisions hindrances to marriage. (11) The system was generally effective, though over-population occasionally occurred. (12) In the fourth sub-group there is no evidence of over-population; (13) the factors are rather different, and (14) pressure comes about by unconscious response to economic conditions. (15) Summarizing the position for all groups we find that owing to the great power of increase, customs restrictive of increase are always necessary, and (16) have taken various forms (17) with varying effectiveness. (18) Changes in quantity are a result rather than a primary cause of historical events. (19) Neither migration (20) nor war is due directly to over-population, though the position as regards quantity may be an element in the situation predisposing nations towards migration and war.
Chapter XII
SOME MODERN PROBLEMS 308
(1) The recent increase in numbers was in response to economic requirements, and affords no ground for pessimism as to the future. (2) The density desirable may be considered from the point of view of moral welfare (3) and of national safety, as well as from the economic standpoint. (4) The importance of minor fluctuations. (5) Methods of limiting increase at the present day. (6) Different ratios of increase as between different classes, (7) between different races in the same country, and (8) between different countries.
Chapter XIII
THE QUALITATIVE PROBLEM 322
We have to ask how far those changes which constitute history are due to germinal changes, and are therefore comparable to changes among species in a state of nature. Analysis of remaining chapters.
Chapter XIV
THE INFLUENCE OF THE ENVIRONMENT AMONG ANIMALS AND PLANTS 325
(1) Observations show that environment and heredity are complementary one to the other. (2) Abnormal stimuli may produce almost any result, but (3) for each species there is a normal environment, to certain elements in which marked responses may be made, though (4) generally speaking sessile organisms are far more responsive to differences in the environment than are free-living organisms. (5) Among free-living species in a state of nature closely related to man, modifications are not of great importance in producing variations.
Chapter XV
THE INFLUENCE OF THE ENVIRONMENT UPON MAN 336
(1) Among men there is no normal environment. (2) The effect of exercise, (3) of general conditions, (4) and of climate. (5) Huntington’s theory of optimum climatic conditions. (6) The effect of food, altitude, &c. (7) Statistical results. (8) Effect of disease. (9) Evidence derived from twins. (10) Conclusion that modifications, with the exception of those produced by disease, are not of great importance, though of more importance than in the case of species closely allied to man.
Chapter XVI
HEREDITY IN MAN 356
(1) Recent work in heredity leads to the conclusion that at the basis of all human characters lies a vast number of unit-factors; but few have yet been recognized, and (2) we have to depend upon statistical data, which show that all mental and physical characters are inherited. Further discussion of the inheritance of (3) disease, (4) temperament, (5) instinct, and (6) intellect. (7) Conclusion.
Chapter XVII
THE EVOLUTION OF PHYSICAL CHARACTERS 368
(1) Preliminary notice of certain difficulties—cause of mutation, strength of selection. (2) During the intermediate period great changes took place, but (3) in general during the first and second periods the tendency was towards the evolution and preservation of certain types, (4) which is comprehensible when the conditions among primitive races are studied. (5) In the third period more variations have been allowed to persist; disease becomes of importance. (6) At all times warfare, migration, and crossing have influenced physical characters. (7) Factors of possible importance other than selection. (8) Conclusion.
Chapter XVIII
THE EVOLUTION OF MENTAL CHARACTERS 385
(1) We have to inquire into the stage of mental evolution reached at different times. (2) After discussing evidence derived from fossils, (3) from the study of primitive races, (4) from Binet-Simon tests, and (5) elsewhere, we conclude that by far the greater part of mental evolution had been accomplished in Palaeolithic times. (6) Conditions in the intermediate period strongly favoured intellect, (7) but in the first and second periods there ceased to be any considerable premium upon intellect, (8) while, though at the opening of the third period some advance was favoured, later conditions merely allowed of the existence of greater diversity. (9) Definite conclusions postponed until tradition has been studied.
Chapter XIX
THE NATURE OF TRADITION 407
(1) The evolution of conceptual thought went hand in hand with that of language, (2) and has passed through a series of stages. (3) The products of conceptual thought are stored up in various ways, (4) are transmitted by language and by the operation of suggestion and sympathy, and (5) are retained by habit. (6) In a relatively unimportant way tradition is present among the higher animals. (7) Tradition moulds the degree and direction of the use of mental faculties, and (8) is naturally selected.
Chapter XX
THE ORIGIN OF TRADITION 419
(1) Supposing other things to be equal, we have to study the influence of differences in fertility and contact upon tradition. (2) Fertility is a purely relative term. (3) The greater the fertility, the greater the incentive to increase in skill and to the transmission of skilled processes. (4) Since fertility is relative there is a shifting of the centres of progress. (5) Contact varies in quantity and quality, and facilitates the transmission and encourages the formation of skill. (6) Contact is hindered by isolation by sea, deserts, and mountains, and is facilitated by rivers. Importance of location and language. (7) Contact also influenced by economic factors which have brought about (8) the evolution from the segmentary to the organic form of social organization. (9) Thus the origin and transmission of tradition have been very greatly encouraged in the third period, (10) though certain influences work against the full realization of the organic type in modern communities. (11) Differences in economic organization are correlated with other differences in social organization.
Chapter XXI
THE RELATIVE IMPORTANCE OF TRADITION AND HEREDITY 437
(1) Definite conclusions are difficult to reach. (2) History in the intermediate period was due to germinal change. (3) The natural endowment of America, (4) Asia, (5) Africa, (6) and of other regions, (7) and their geographical features, (8) suggests that history in the subsequent periods was chiefly of the nature of traditional change. (9) Though germinal changes are important they do not account for the outstanding events, though they have contributed to them. (10) Lesser germinal changes colour tradition, but are not determining factors in history. (11) Known germinal changes, such as those produced by crossing, are less important than accompanying traditional changes, (12) of which there are many instances in the third period. (13) The direct effect of the environment is not negligible, and has influenced the course of history. (14) The cyclic course of civilization, which has been attributed to germinal change, is in the main due to traditional changes. (15) Tradition at the present day overlays the manifestation of mental characters in so great a degree that (16) differences between classes may well seem wholly traditional, but (17) psychological tests and (18) other evidence show that innate mental differences are present, (19) though it is difficult to appraise their value and the importance of modern differential fertility.