From the Guardian's article on scientific hoaxes
The amazing Tasaday tribe
In 1971 Manuel Elizalde, a Philippine government minister, discovered a small stone age tribe living in utter isolation on the island of Mindanao. These people, the Tasaday, spoke a strange language, gathered wild food, used stone tools, lived in caves, wore leaves for clothes, and settled matters by gentle persuasion. They made love, not war, and became icons of innocence; reminders of a vanished Eden.
They also made the television news headlines, the cover of National Geographic, were the subject of a bestselling book, and were visited by Charles A Lindbergh and Gina Lollobrigida. Anthropologists tried to get a more sustained look, but President Marcos declared a 45,000-acre Tasaday reserve and closed it to all visitors.
After Marcos was deposed in 1986, two journalists got in and found that the Tasaday lived in houses, traded smoked meat with local farmers, wore Levi's T-shirts and spoke a recognisable local dialect. The Tasadays explained that they had only moved into caves, donned leaves and performed for cameras under pressure from Elizalde - who had fled the country in 1983 along with millions from a foundation set up to protect the Tasaday. Elizalde died in 1997.
The great IQ scandal
Sir Cyril Burt, professor of psychology at University College London, used studies of twins to prove that IQ was mostly inherited. It was the largest study of its kind, so even those who rejected his explanation accepted his figures. He was one of the architects of the much-debated 11+ examination, which determined children's secondary school careers.
After Burt's death in 1971, researchers were shocked to find that some of the key research into IQ was fraudulent.
"The numbers left behind by Professor Burt are simply not worthy of our current scientific attention," said one.
Argument continues about the extent of the fraud, but some people claim he not only invented some of the data but even the names of his research assistants. Even today, the argument over how much of your IQ is down to your genes, and how much down to nurture, remains open.
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