Do people in poor nations have lower IQs?
People in poor and developing countries, where diseases are rife, may have lower intelligence (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 fighting disease. 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, London, 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.
Image: Rwandan refugees wait for United Nations food aid
People in the Third World not intelligent?
"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," he said.
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 of extraordinary civilizations.
The research could be abused to rationalise racism, just as the Nazis perverted scientific study in the 1930s, some critics said.
Image: Students study in a government-run school at a slum
Photographs: Mukesh Gupta/Reuters
HIV has a high infection rate in low-IQ nations
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 development.
Professor Richard Lynn of Ulster University said the picture was complex, with low national IQs partly propagating the spread of infectious diseases.
HIV has 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.
Image: A child waits for water from a non-governmental organisation
Photographs: Parth Sanyal/Reuters