A GREATER POPULATION DOES NOT DAMAGE HEALTH, 

             OR PSYCHOLOGICAL AND SOCIAL WELL-BEING



... the closer man approaches the limits of ultimate 
density or "carrying capacity," the more probable is 
nuclear warfare.   Reid and Lyon, 1972, Preface

CHAPTER 32: TABLE OF CONTENTS
Population Density and Physical Health
The Case of Malaria
Some Other Health Examples
The Psychological and Sociological Effects of Crowding
Population Growth and Intelligence
Population Density and War
What, Then, Determines Health?
Conclusions

   Most of this book studies material matters usually considered to be in the domain of 
economics - the standard of living, natural resources, and even the environment.  This 
chapter now goes beyond ordinary economics to discuss health and related issues in 
connection with population size and growth, mainly because some readers feel that the 
subject is incomplete without such discussion. 
   In earlier centuries high population density often affected health adversely. For 
example, during the industrial revolution, the death rate was generally higher in cities 
than in the country because of poor sanitation and contagious diseases.  But though many 
people still believe that the sparsely-populated countryside is healthier than the city, 
there seems no evidence that nowadays higher population density is unhealthy; if 
anything, the opposite is true.  We'll tackle the issue of physical health first; the 
effects of population density on psychological and social well-being will occupy the 
second part of the chapter, along with brief discussion of war.

             POPULATION DENSITY AND PHYSICAL HEALTH

   Feeling and being healthy is as valuable as anything else an economy can provide. 
Moreover, health is a central issue in the functioning of the economy - healthy people 
work harder and better than sick people, and prevalent illness hinders economic 
development in many poor countries.  
   Life expectancy is the key measure of a country's health situation, as discussed in 
chapter 9 [, on pollution]. There it was shown that population density and growth have no 
apparent negative effects on life expectancy; rather, the effects may be positive.
   In earlier times, living in areas of high population density - cities - undoubtedly 
reduced one's life expectancy. In the seventeenth century, when William Petty wrote about 
London, the death rate was so much higher in urban than in rural areas (and probably the 
birthrate was so much lower) that cities like London depended on migration from the 
country to maintain their populations. In 1841 the life expectancy for males was 35 years 
in London but 40 years in the rest of Great Britain.  And life expectancy in the U.S. was 
still much lower in urban places than in rural areas from 1900 until 1940 for white 
males: 44.0 versus 54.0 (1900); 47.3 versus 55.1 (1910) 56.7 versus 62.1 (1930); and 61.6 
versus 64.1 (1939).
   In more recent times in developed nations, however, as communicable diseases have been 
controlled with sanitation and other public health measures, this disadvantage of 
population density has disappeared.  For example, by 1950-52 life expectancy in London 
had reached 67.3 years compared with 66.4 years in the rest of Great Britain. 
   In most developing countries for which there are data, the death rate is lower in 
cities than in rural areas, though there are exceptions.
  As of 1959-1961 in the U.S., the death rate was slightly higher for large cities but 
lower for small cities, compared to non-metropolitan counties,  but the high inner-city 
death rate that explains this pattern is surely due to factors other than epidemic 
disease, unlike earlier times.
   More generally, the historical picture in the West during the past half millennium, 
and in most countries in the world during the past few decades, has shown concurrent 
growth in all three key factors - population density, income, and life expectancy. This 
suggests that increased density and increased income - either individually or in 
combination - benefit people's life expectancy and health, as well as vice versa.
	Consider this example of the health in the "good old days" in one of the 
wealthiest and most civilized places in the ancient world - Metaponto, a Greek colony in 
the south of Italy.  
In overwhelming numbers, the people had been 
malnourished, disease-ridden and injury-lanted.

	Six out of every 10 had decayed teeth...More than 
three-quarters had tooth enamel malformed in a way known 
to be caused by serious disease or severe 
malnutrition...56 percent showed signs of signficant 
disease or injury...
	The skeletons also revealed a large number of broken bones gthan had not een set 
and had hdealed in distorted way.

	These findings surprised the anthrologist who supervised the work.  "You read the 
literature of classical Greece and you get the picture of a wonderful society...But what 
we see now is that things were pretty awful"
   Why is health better where there is higher population density? Let's make a negative 
point first. There is nowadays no reason why population density should worsen health now 
that the important infectious environmental diseases, excepting malaria, have been 
conquered.  And malaria - which many medical historians consider to have been the most 
important of mankind's diseases - flourishes where population is sparse and where large 
tracts of moist land are therefore left uncultivated.  In these areas increased 
population density removes the mosquitoes' breeding grounds.

The Case of Malaria

   As Pierre Gourou put it,

     Malaria is the most widespread of tropical 
diseases....It attacks (or did until recently) something 
like one-third of the human race, but in practice all the 
inhabitants of the hot, wet belt may be considered to be 
more or less infected.  Malaria weakens those whom it 
attacks, for the bouts of fever sap their physical 
strength and make them unfit for sustained effort.  Hence 
agriculture does not      receive all the care it needs, 
and the food supply is      thereby affected.  In this 
way a vicious circle is formed. Weakened by insufficient 
nourishment, the [infected person's] system offers small 
resistance to infection and cannot provide the effort 
required to produce an adequate supply of food.  The 
malarial patient knows quite well that a bout of fever 
may be the unpleasant reward for hard work....
Undoubtedly, malaria is largely responsible for the poor 
health, small numbers, and absence of enthusiasm for work 
of tropical peoples....
In the pre-scientific age, men kept the most serious      infectious diseases in check by 
organizing the total      occupation of the land, thus eliminating the breeding      
places of the mosquito.  Such occupation demanded a high density of population and a 
complete control of land use, and hence the interdependence of a highly organized 
agricultural system (itself a function of soil quality, reliable climate and a certain 
degree of technical competence), a dense population and an advanced political 
organization....It is also difficult to improve sanitation and health in sparsely peopled 
areas; anti-malarial campaigns stand but small chance of lasting success, whilst the 
tsetse fly finds such areas very much to its liking, for it is impossible for a 
population of ten or a dozen persons to the square mile to keep down the vegetation to a 
level unfavorable to this insect.  Health services are difficult to maintain, and doctors 
and hospitals are inevitably far removed from patients whilst education is almost 
impossible.

   The data in table 32-1 support Gourou's argument, 
showing that a low population is associated with a high 
incidence of malaria on Ceylon. Of course one might 
wonder whether population is low in malarial areas 
because people simply chose to move away from malaria.  
But the history of Ceylon suggests otherwise.
     The ancient civilization of Ceylon had centered in the      area with hyperendemic 
malaria. The ruins of 10,000 dams testify to the level and magnitude of this civilization 
in successive stages of history. Decay of the ancient order was associated with collapse 
of the irrigation systems, emergence of conditions that favored transmission of malaria, 
and retreat of the Singhalese to the nonmalarious area of the island.

   TABLE 32-1. Population, Area, and Population Density of    
   Districts of Ceylon (Sri Lanka) Grouped by the Endemicity of       
   Malaria in the Districts (old T 18-1)
Likewise, some historians have suggested that the decline of the Roman Empire was in 
large part due to the spread of malaria after political upheaval and decreased population 
density interfered with the maintenance of the drainage system.                        
   Looking now to examples of improvement rather than retrogression, the history of 
England was heavily affected by the decline of malaria induced by population growth. In 
London, "Westminster was paved in 1762 and the City in 1766...and the marshes near London 
were drained about the same time." In 1781 a writer observed that "very few die now of 
Ague [malaria] in London."
   The history of the U.S. also reveals the interplay between malaria, population, and 
economic development:

...a mighty influence buoying up wages paid to the men      building canals during the 
1820's and 1830's was the      danger of yellow fever and malaria.  Built through marsh 
and swamps (in many instances) to reduce construction problems, the canals were known as 
killers....As the country was settled, the marshy land where malaria was bred was filled 
in.  Buildings covered the waste spaces where [disease carriers] could survive.

   Because of DDT and other synthetic pesticides, medical technologists thought for a 
time that population density was no longer necessary to prevent malaria. Malaria was 
considered beaten.  But throughout the world, the disease has rebounded. India went from 
75 million sufferers in 1953 to 50,000 cases and "total control" in 1968, but in the 1971 
epidemic there were 1.3 million reported cases, rising to 5.8 million cases reported in 
1976, or by another estimate, "the number of cases reached at least 30 million and 
perhaps 50 million."  As the use of DDT went down, "Endemic malaria returned to India 
like the turnaround of a tide".  Also, "Sri Lanka...reduced malaria from about three 
million cases after World War II to just 29 in 1964".  But then DDT was banned. And due 
to the evolution of pesticide-resistant strains of carrier insects and the concomitant 
damage to the insects' natural predators, pesticides soon lose their effectiveness. The 
disease has returned in force; by 1970 Sri Lanka may have had a million cases of malaria 
per year. 
	Barry Commoner gives another example:
In Guatemala, some twelve years after the start of a           
malaria "eradication program" based on intensive use of      
insecticides, the malarial mosquitoes have become      
resistant and the incidence of the disease is higher      
than it was before the campaign. The levels of DDT in the 
milk of Guatemala women are by far the highest reported 
anywhere in the world thus far.

   Other public health experts also are grim about the 
prospects of fighting malaria with chemicals.
     Asked whether we are winning or losing the battle against tropical diseases, some 
experts, among them Dr. B. H. Kean of Cornell University Medical College, answer promptly 
that we are losing.  He notes that malaria, for example, seemed almost conquered in the 
decade or so after World War II.  But since then mosquitoes have become resistant to 
pesticides, and the malaria parasite has learned to cope with some of the more widely 
used drugs.

   Today again the only sure weapon against malaria seems to be      increased population 
density.

Some Other Health Examples

   Not only is the infectious-disease drawback of population density a thing of the past, 
but higher density also has many positive effects on health even aside from control of 
insects that carry malaria, sleeping sickness (the tsetse fly in Africa), and other 
diseases. For example, cities in the modern world have safer water supplies than do rural 
areas. Medical care is better in cities, and medical help arrives quicker or is easier to 
reach where there is a good transport system, itself the result of population density 
(see chapter 25).
   We must also remember the additional knowledge, created by more people, that 
contributes to health. Item: Modern emergency medical systems in the U.S. are saving 
lives after auto accidents and in other emergencies. The population-induced road network 
of the U.S. is a key to the success of such systems. A country with a much sparser 
population would find such emergency service much more expensive. And last, it takes 
imagination and skill - human minds and hands - to invent and develop such medical 
systems. Item: Electrical wiring is now safer than it used to be. Many old houses have 
been rewired more safely since wiring ideas were developed by "additional" people - that 
is, by people who may not have been born if population growth were lower. And new houses 
are built, with safer wiring, because population growth (together with increased income) 
creates new demand for houses. (In Ireland, where population has not grown much in the 
past century, one seldom saw a new building at the time of the first edition of this 
book. I shudder at the electrical monstrosities that must lie within some of the larger 
older buildings.)

      THE PSYCHOLOGICAL AND SOCIOLOGICAL EFFECTS OF CROWDING

   Many believe that high population density has bad psychological and sociological 
effects. This is mere supposition.  High population density has indeed been shown to harm 
animals. But it has not been shown to harm humans. Rather, it is too much isolation that 
harms humans. The belief that crowding harms people is supported only by analogies to 
animals, analogies that are patently misplaced.
   For hundreds of years biologists have observed that, when animals are confined to a 
given area with given resources, "unhappy" events occur. An increased death rate was 
noted by such observers as Benjamin Franklin. Modern students such as Konrad Lorenz and 
John B. Calhoun have focused on "anti-social" and "pathological" behavior in fish geese, 
and Norwegian rats. For example, the title of Calhoun's famous article is "Population 
Density and Social Pathology." These biologists simply assumed that the same processes 
necessarily occur with humans.

   The earliest - and still most crushing - rebuttal is that given to Benjamin Franklin 
by, of all people, Malthus himself after he learned some facts and wised up subsequent to 
publishing his first edition. (This episode is described in chapter 24.)
   Biologist Julian Huxley explains how we go wrong in 
reasoning from animals to people.
We begin by minimizing the difference between animals and 
ourselves by unconsciously projecting our own qualities 
into them: this is the way of children and of primitive 
peoples. Though early scientific thinkers, like 
Descartes, tried to make the difference absolute, later 
applications of the method of scientific analysis to man 
have, until quite recently, tended to reduce it again.  
This is partly because we have often been guilty of the 
fallacy of mistaking origins for explanations - what we 
may call the "nothing but" fallacy: if sexual impulse is 
at the base of love, then love is to be regarded as 
nothing but sex; if it can be shown that man originated 
from an animal, then in all essentials he is nothing but 
an animal. This, I repeat, is a dangerous fallacy.
We have tended to misunderstand the nature of the                difference between 
ourselves and animals.... The critical point in the evolution of man - the change of      
state when wholly new properties emerged in evolving life - was when he acquired the use 
of verbal concepts and could organize his experience in a common pool. It was this which 
made human life different from that of all other organisms.
And thus human organization is different from animal organization, especially in people's 
capacity to create new modes of organization.

   Here is a similar critique of Lorenz's analogies:
     [Lorenz has a] regrettable tendency to describe animal      behavior in human terms 
- "married love" in monogamous      geese, for example.  This cannot be dismissed as 
harmless anthropomorphism in the service of popularization, for it promotes the very 
misuse of analogy that lies at the heart of Lorenz's problems.  A curious twist of logic 
to be sure - impose a human concept by dubious metaphor upon an animal, then re-derive it 
for humans as obviously "natural."  Thus, a drake that tried to copulate with Lorenz's 
boot is a fetishist by "exact analogy," and a mob of geese frightening off a coati-mundi 
play the same role as a human picket line.
   So much for evidence from the animals.  Despite common presumption, the sociological 
data show that human population density - as measured by the number of people per unit of 
land area, which is relevant to the issue of population growth on earth - has no general 
ill effects on such measures of welfare as longevity, crime rates, mental illness rates, 
and recreational facilities.  
   After it became apparent that the concentration of people into cities is not 
necessarily connected to pathology, those who worry about these matters turned to 
crowding at home and work. Here the results are mixed about whether people are affected 
by crowding as animals are.  One study of "the effect of household and neighborhood 
crowding on the relations between urban family members" showed that "crowding is found to 
have little or no effect," while Omer R. Galle and co-workers found that a larger number 
of people per room in Chicago accompanied increased mortality, use of public assistance, 
juvenile delinquency, and admission to mental hospital.  But density and crowding are not 
necessarily found together. Slums at urban fringes often have low density, and "these 
areas have more pathology than high-density slums."  The likeliest explanation of the 
pathology that Galle and associates found is simply poverty.  
   The most ambitious experimental tests, conducted by 
psychologist Jonathan Freedman (once an associate of Paul 
Ehrlich and a believer that density is pathological), led 
to the conclusions that
     intuitions, speculations, political and philosophical theory appear to be wrong in 
this respect....People who live under crowded conditions do not suffer from being 
crowded.  Other things being equal, they are no worse off than other people....It took me 
and other psychologists working in this area many years to be convinced, but eventually 
the weight of the evidence overcame our doubts and preconceptions.

   In any case, the amount of crowding (lack of personal space) has been going down in 
the U.S. as income has risen, and along with an increase in total population and density 
in metropolitan areas.  The percentage of households living in "crowded conditions" (more 
than one person per room) has been:  1900, over 50 percent; 1940, 20 percent; 1950, 16 
percent; 1960, 12 percent; 1970, 8 percent.  (Given that this decline has occurred even 
as population has been rising, would those who worry about crowding offer population 
growth as a salutary prescription?  Relax, I'm just teasing.)
   Once I had a conversation with a woman who was frantically worried about the ill 
effects of crowding - as we sat haunch to haunch in a football stadium packed with 75,000 
people! She saw no humor in my pointing out that she seemed to be enjoying herself 
tolerably well under the circumstances.
 
POPULATION GROWTH AND INTELLIGENCE
   In the first half of the Twentieth Century, many people worried about a decline in 
human intelligence due to the assumed pattern of differential fertility.  The chain of 
logic went as follows:  1) Poorer families have lower intelligence than richer families.  
2) Intelligence is inherited by children from their parents. 3)  Poorer families have 
more children than richer families.  4) The average level of intelligence must fall.  
This line of argument was again stated by psychologist Richard Herrnstein. 
   Highly competent and respected statisticians and 
psychologists even estimated the extent of the decline 
that was supposedly occurring. 

Cattell estimated that the average I.Q. is      declining 
at the rate of 3 points per generation.       Fraser 
Roberts reported that based upon his studies of the child 
population of Bath, England, the fall in average I.Q. was 
about 1 1/2 points per generation. In the United States, 
Lentz calculated that in the urban population the decline 
in the median score from one generation to another was as 
much as 4 to 5 points. Lorimer and Osborn concluded that 
the average decline in the median I.Q. score was 0.9 of a 
point per generation.

It should be remembered that these calculations are 
theoretical and are based upon observations on a single 
generation.  No one has yet reported investigations of 
I.Q. scores in successive generations which support these 
claims.

   This idea is then extended by some to assess social policies.  For example, consider 
the following remark in the context of discussion of "the Jukes-Kallikaks `bad heredity' 
concept":  "Can it be that our humanitarian welfare programs have already selectively 
emphasized high and irresponsible rates of reproduction to produce a socially relatively 
unadaptable human strain?" 
   Otis Dudley Duncan criticized this body of thought on both theoretical and empirical 
grounds.  His most telling points are a) the existing studies of I.Q. change over time 
did not reveal a decline but rather an increase (though Duncan did not interpret the 
apparent increase as being meaningful); and b) applying the same logic to data on 
differential height (which in contrast to intelligence, is incontrovertibly correlated 
genetically between parents and children) would lead one to expect a decline in heights 
from generation to generation, which has not been observed. (It is also relevant that 
persons with severely limited mental capacities have low life expectancies and few 
offspring.)
   A point which has gotten little or no mention: It is reasonable to assume that a given 
individual's intelligence (whatever that means), or any aspect of it, is affected by the 
individual's genes without assuming that there is a correlation between the intelligence 
of parents and children.  It is quite possible that any aspect of intelligence depends 
upon the combination of a large number of genes which may agglomerate in a random 
fashion, and hence while the individual genes are inherited from the parents the outcome 
need not be.  This is certainly the case among such conditions as mongoloidism;  the 
mongoloids do not reproduce themselves, and yet they continue to appear in each 
generation, perhaps at a constant rate.  And if homosexuality is affected by genetic 
makeup, the same would be true of that condition.
   My layman's assessment: Lack of empirical support, and the existence of a powerful 
critique, seem to me to overwhelm the proposition that intelligence declines due to a 
high birth rate among the poor. Yet the apparently-plausible belief continues to reappear 
in each generation.
   [OUT OUT The controversy about differences in intelligence among "races", in 
connection with differences in birth rates among those groups, is related intellectually, 
though it seems little supported by evidence. 
   As to the effect of family size on children's intelligence, the evidence is so mixed 
that it defies summary.  Whatever I.Q. differences exist among children in families with 
one, two, or three children are small by any meaningful measure.  Other reviews offer 
conflicting points of view.  There is little doubt that, on average, children with no 
brothers or sisters do worse than children with one or two siblings.  On balance there is 
little reason to believe that, all else equal, a larger family lessens a child's 
intelligence or chances in life. And the long-run trend is toward smaller families 
anyway, as populations grow and countries develop - so all else is not equal.

                   POPULATION DENSITY AND WAR
   War between and within nations is perhaps the most grisly outcome that population 
density or growth is said to threaten.  Expanding on the chapter's headnote, the common 
view is as follows:  "At the present rate of world population increase, overpopulation 
may become the major cause of social and political instability. Indeed, the closer man 
approaches the limits of ultimate density or `carrying capacity,' the more probable is 
nuclear warfare.  This popular view is espoused by the U.S. State Department, AID and 
CIA, and has been the justification for population control programs abroad. (See 
quotations from the secret National Security Council plan of 1974, declassified only in 
1989, in chapter 36.)  The simple fact, however, is that there is zero evidence 
connecting population density with the propensity to engage in war, or even fist fights. 
   A booklength cross-national statistically-intensive multi-variable study by Douglas A. 
Hibbs, Jr., found that "other factors held constant, the rate of population growth does 
not influence magnitudes of mass political violence within nations."  And in a study of 
six measures of political instability in Latin America between 1968 and 1977, Alfred G. 
Cuhsan found "no reason to believe that either population growth or density is a cause of 
political instability." 
   Nazli Choucri concluded that what she calls "demographic" factors sometimes lead to 
conflict.  But the key demographic factor in her analysis is the relative rate of 
increase in ethnic groups, rather than increase in population size or population density 
per se.  This can be seen most clearly by listing the wars that she considers 
"archetypical cases" of "population dynamics and local conflict":  the Algerian War of 
Independence, 1954-62; the Nigerian civil war; the two wars involving Indonesia; the 
conflicts in Ceylon and El Salvador-Honduras; and the Arab-Israeli series of wars.  None 
of these seem, to my layman's eye, to be conflicts undertaken to obtain more land or 
mineral resources so as to increase the standard of living of the group initiating the 
conflict.  To show that population growth causes conflict, one would need to show that 
two neighboring countries or groups, both of whom are growing rapidly, are more likely to 
come into conflict than two neighboring countries or groups neither of whom are growing 
rapidly.  This Choucri has not shown.  In Choucri's way of looking at the matter, 
conflict could as easily be caused by one country or group reducing its growth rate 
relative to another country or group, as by one increasing its relative growth rate.  And 
in fact many have argued that it was just so in the case of France and Germany -- that 
France's low birth rate induced the French-German wars.    
   Furthermore, as we saw in the Afternote to chapter 29, the traditional economic motive 
for war - acquiring farm land - is fast disappearing. For economically advanced nations, 
it doesn't pay to make war to get another nation's agricultural territory.  And a 
sensible citizenry wouldn't even take a slice of another country as a gift. 

                 WHAT, THEN, DETERMINES HEALTH?   
   If population density and growth are not the determinants of health in the short run, 
what does determine how sick or healthy we are?  By now the answer has become clear.  A 
community's health depends upon a) how much scientific knowledge has already been 
discovered, which is much the same as asking which year we are talking about, and b) how 
economically advanced the community is.  [OUT ?Figures 32-1 and 32-2 show the strong 
relationship of income level to air and water pollution in various countries. 
         OUT?  Figs 32-1 and 32-2 from UNEP/WRI data books
   We also know more now about what causes modern populations to become less healthy: bad 
government, for example.  One channel through which bad government harms people is 
through pollution.  It now is clear that the recently-socialist countries in Eastern 
Europe have very high levels of pollution, both because socialism made them poor and 
because socialism predisposes to pollution over and above the income effect by 
emphasizing production at any cost.  Data on life expectancy in chapter 00 showed that 
low income and socialism also predispose to high mortality rates, and that some mortality 
rates have even been rising in the recently-socialist countries, especially in the 
working ages for males; *****see also Figure 32-1 for the old Soviet Union****.  The 
morbidity for all causes except cancers (which one generally suffers from only after 
living to an old age) and auto accidents (which require that the society have many 
vehicles) are higher in recently-socialist countries, and the unfavorable ratio for 
socialist versus non-socialist countries is increasing, as Figure 32-3 shows.  Even 
infant mortality rose in the Soviet Union from the 1970s (though not in the rest of 
Eastern Europe, in contrast to experience everywhere else in the world.  The high rates 
of alcohol and cigarette consumption in Eastern Europe are interesting in this connection 
(see Figure 32-4), though subject to several interpretations.
Figure 32-1 from Feshbac


Figs 32-3[eb from Eberstadt or Bernstam?] 32-4 and ? on cigs and alcohol in E. Europe 
from Eberstadt
   Because factors other than population density and growth explain much of the variation 
in health, now as in the past, the argument that higher population density does not 
damage health is strengthened.
   In the very long run, then, population growth leads to better health because it leads 
to more discovery of new scientific knowledge (see chapter 26) and to economic 
advancement.

                           CONCLUSIONS

   Regarding the purported ill effects of population density, the charges are many and 
imaginative.  The chapter covered the main ones that people have written about, though 
there are many other ill effects of population density that one may concoct.  The overall 
verdict must be "Innocent." And this is not for lack of evidence. As the most recent 
extensive review sums up, "It is reasonable to conclude that the density-pathology 
hypothesis fails to be confirmed within urban areas. When social structural differences 
among neighborhoods are considered (held constant) population density appears to make a 
trivial difference in predicting pathology rates."

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