- Lynn, Richard and Tatu Vanhanen. IQ and the Wealth
of Nations. Westport, CT: Praeger,
2002. ISBN 0-275-97510-X.
- Kofi Annan, Secretary General of the United Nations, said
in April 2000 that intelligence “is one commodity equally distributed
among the world's people”. But is this actually the case? Numerous
studies of the IQ of the populations of various countries have been
performed from the 1930s to the present and with few exceptions, large
variations have been found in the mean IQs of countries—more than
two standard deviations between the extremes—while different studies
of the same population show remarkable consistency, and countries
with similar populations in the same region of the world tend to have
roughly the same mean IQ. Many social scientists believe that these
results are attributable to cultural bias in IQ tests, or argue that
IQ tests measure not intelligence, but rather proficiency in taking
IQ tests, which various educational systems and environments develop
to different degrees. The authors of this book accept the IQ test
results at face value and pose the question, “Whatever IQ measures, how
accurately does the average IQ of a country's population correlate with
its economic success, measured both by per capita income and rate of
growth over various historical periods?” From regression studies of 81
countries whose mean population IQ is known and 185 countries where IQ
is known or estimated based on neighbouring countries, they find that
IQ correlates with economic development better than any other single
factor advanced in prior studies. IQ, in conjunction with a market
economy and, to a lesser extent, democratic governance “explains”
(in the strict sense of the square of the correlation coefficient)
more than 50% of the variation in GDP per capita and other measures of
economic development (of course, IQ, economic freedom, and democracy
may not be independent variables). Now, correlation is not causation,
but the evidence that IQ stabilises early in childhood and remains
largely constant afterward allows one to rule out many potential kinds
of influence by economic development on IQ, strengthening the argument
for causation. If this is the case, the consequences for economic
assistance are profound. For example, providing adequate nutrition
during pregnancy and for children, which is known to substantially
increase IQ, may not only be the humanitarian thing to do but could
potentially promote economic progress more than traditional forms of
development assistance. Estimating IQ and economic development for
a large collection of disparate countries is a formidable challenge,
and this work contains more correction, normalisation, and adjustment
factors than a library full of physics research—close to half
the book is data tables and source documentation, and non-expert
readers cannot be certain that source data might not have been
selected which tend to confirm the hypothesis and others excluded.
But this is a hypothesis which can be falsified by further research,
which would seem well-warranted. Scientists and policy makers
must live in the real world and are ill advised to ignore aspects
of it which make them uncomfortable. (If these comments move you
to recommend Stephen Jay Gould's The Mismeasure of Man, you
needn't—I've read it twice before I started keeping this list, and
found it well-argued. But you may also want to weigh the points raised
in J. Philippe Rushton's critique of Gould's
book.)
March 2004 