Humanity facing ‘Age of Stupidity’, scientists say

In 1936, eminent British psychologist Raymond Cattell did some sums and concluded that the human race should be evolving to become more imbecilic with each generation. He quickly realised that he was wrong, and for 80 years, study after study has shown that we are, if anything, getting brighter by the decade.

Now, though, a group of scientists has claimed that Cattell’s gloomy forecast may be about to come true after all: humanity could finally be on the brink of the Age of Stupidity.

As clever people have fewer and fewer children, our collective ‘‘genetic intelligence’’ – the IQ we inherit from our parents – is waning.

Until now, the decline has been masked by improvements in education and factors such as nutrition, which boost some aspects of intelligence. Yet that phenomenon seems to be running out of steam, particularly in rich countries.

Michael Woodley, scientist in residence at the Technical University of Chemnitz, Germany, and lead author of the new paper, said that GDP and the rate of innovation could begin to stagnate, while breakthroughs such as Einstein’s general theory might become fewer.

Genes are known to have a strong influence over general intelligence, a measure of raw brain power. Woodley’s work suggests that this has fallen ‘‘substantially’’ since the 19th century, at about 0.4 IQ points per decade.

Previous studies have shown that people’s reaction times, working memory scores and ability to use arcane words correctly have of relativity declined in the past century or so, while other signs of ‘‘specialised’’ intelligence, such as literacy and maths skills, have improved.

Woodley and his colleagues compared several databases of single-letter genetic mutations linked to general intelligence against IQ scores based on tests from 64 countries. They found that genetic changes across different nations seemed to be driving a slow but steady fall.