Evening star., 1940-05-15
Doubled Population
For South America
Is Seen in 29 Years
Science Congress Hears
New World Preserves
Biological Youth
BY THOMAS r. HENRY.

Biological Youth
BY THOMAS r. HENRY.
South America will double It's |
population In 70 years and the whole |
Western Hemisphere in II years at |
present rates of growth and without |
immigration. |
This will happen in spite Of de-
clining birth rate in most Of the
countries Of the New World.
before the Eighth American Science
Congress here today by DR.. Ray
mond Pearl Of Johns Hopkins Uni
yersity from q study Of present |
birth -and-death trends which in
cluded 90 per cent Of the earth's |
population.
At the same time, he said, the |
populations Of Europe are declining, |
even without the present war, but |
the density for the continent as a |
whole is so great that there is bound |
to be an almost irresistible irnmi-
grafton pressure on sparsely popu-
lated South America.
Density Gauged.
The Old World, he said, has 81
per cent Of the earth's 2.0OO, 900 900 !
human beings living on 81 per cent |
Of the total land, while the New |
World has 13 per cent on 80 per cent |
Of the land. But, said DR.. Pearl, his |
survey shows great variations of |
population density in the Western |
Hemisphere. Central America and
Mexico have 81 persons per square |
mile, the United States and Canada |
II and South America as . whole |
103. Europe has 100 and Asia 100.
This relative abundance of land |
per person. he said, gives the New
World as whole biological |
youth" since one Of the greatest |
factors in curbing population growth !
Is worry over q poverty-stricken fu-
ture. The mean population increase
per year for the United States and
Canada since 1920. he said, has been
about lh per cent a year. For
South America as a whole it has
been "a per cent, and for the West
ern Hemisphere as a whole 16 per
cent. But in Europe for the same |
period it has been only 8 per cent.
Colors Psychological Outlook.
Even aside from biological factors |
involved. DR.. Pearl pointed out, this
means a great difference In the !
psychological outlook OF the popula-
tions. The old are increasing at. the |
Expense OF the young and living be-
comes slower and more cautious. |
There Is less and less inclination to |
take chance.
He divided mankind into three
age groups-birth to Is, Is to so and
so to death. The productivity of a
nation depends almost entirely on
the middle group, who do all the |
work and generally support the
others, either as individuals or |
through national tax programs. |
The Western Hemisphere, his sur
vey shows, has Al per cent of its |
population in the first group and 8 |
per cent in the last-with so per
cent in the productive years. For
South America as a whole, the fig
ures are, respectively, 80, 81 and 10. |
For the United States and Canada
they are 81, 48 and II. Thus South |
America has 3 per cent more of its |
population to do Its work. For |
Europe the figures are %, So and 20. |
The prospect, however, Is that nor |
mally the third group will increase
in Europe at the expense Of the mid
die group, since there is such a
small group of children to provide
requirements.
Biological Vitality Measured.
The actual population status Of a
country. DR.. Pearl said, can best be
determined by so-called vital in
dex, mathematical computation OF
birth and death rates. An index of
100 means that group is remaining
exactly stationary in numbers year
after year. South America as q
whole has an index of 206, Central
America of l78, North America
100; the Western Hemisphere, l76,
and Europe only ISL. Thus, he said.
the New World is % points above
Europe in biological vitality, accord
ing to this measure. Only two Eu-
ropean countries go above 200. the
Netherlands and Iceland.
The New World is able to take
care Of itself from the point of view
Of number and vitality of its popu-
lation, DR.. Pearl said, but he
stressed that many will raise the
question as to quality Of population |
and maintain that some of the
present European peoples are better
human material. Actually, he
stressed, there is no way whatso-
ever of measuring the quality Of a
population as to intelligence or ca
pacity for progress. All such meas
ures proposed, he said, have been
measures Of individuals and it Is
impossible to obtain large enough
samples to apply them to peoples as
q whole. Such discussions, he said,
always become clouded with racial
prejudice and individual animosity.
But above all, he stressed, the New
World must preserve its youth and
always leave itself elbow room for
expansion. When this is no more old
age will have set in, as is now the
case In Europe.
Existence of rubber trees suitable
for planting in South America which
produce skiold the crop now OBJ
tanned per acre on the average was
described before the Scientific Con-
gress here today.
At the same time. it was predicted
by Loren G. Polhamus, rubber ex-
pert Of the United State Agriculture
Department, the world may be Just
on the Threshold of the age of rub
ber, with new uses, such as for road
building and in structural materials,
constantly coming to light.
The new rubber trees, he ex-