London: People in poor and developing
countries, where disease is rife, may have lower IQ levels
because they have evolved to develop stronger immune systems
rather than intelligence, a controversial study has claimed.
The study by a team from the University of New Mexico
suggested that the bodies of people in those countries develop
a natural mechanism to divert energy from brainpower to
Children under five use most of their energy for brain
development and this can be restricted if the body has to
fight disease, the researchers said.
For their research, the team compared data from worldwide
IQ studies with disease maps drawn up by the World Health
Organisation and concluded that the higher the level of
infectious disease in a country, the lower the average
national IQ, the Daily Mail reported.
"The effect of infectious disease on IQ is bigger than
any other single factor we looked at," said Chris Eppig, lead
author of the study.
"Disease is a major sap on the body`s energy, and the
brain takes a lot of energy to build. If you don`t have
enough, you can`t do it properly.
"The consequence of this, if we`re right, is that the IQ
of a nation will be largely unaffected until you can lift the
burden of disease."
The researchers, who reported their findings in the
Proceedings of the Royal Society, claimed their work could
explain why national IQ scores vary around the world and are
lower in some warmer countries stricken by diseases such as
malaria, tetanus and tuberculosis.
Meanwhile, some critics warned that the study could
become an excuse for racism if it was used to suggest that
people in the `Third World` are not as intelligent as those in
cooler, richer climes.
Others pointed out that the ancient Persians, Greeks and
Romans lived in hot climates and still boasted extraordinary
The research could be abused to rationalise racism, just
as the Nazis perverted scientific study in the 1930s, some
Experts pointed out that children fighting debilitating
disease are likely to miss a lot of school, which could be the
real reason for a lower IQ score, not compromised brain
Professor Richard Lynn of Ulster University said the
picture was complex, with low national IQs partly propagating
the spread of infectious diseases.
HIV had a high infection rate in low-IQ nations, he said,
because people did not understand how it was contracted and
relied on baseless superstitions to avoid it.