IQ has fallen since Victorian age and genes are to blame

Our mental abilities have undergone a significant decline since the Victorian era, as genes driving intelligence have become less common since the 19th century, scientists say. Researchers, led by Michael Woodley from the Free University of Brussels in Belgium, used a bank of genomes recovered from the remains of 99 people from central and eastern Europe.

The oldest of these died in about 2,000 BC while the latest was from the 7th century AD. Comparing these against the DNA of 503 modern Europeans, the researchers found that the mutations linked to higher general cognitive ability (GCA), which enables people to solve problems had become more common as time went by.

The results were confirmed in a separate analysis of the genes of 66 more ancient people who had lived across 3,200 years, `The Times’ reported.

Mankind evolved to become more intelligent over the past few millennia due to circumstances that have favoured the survival of the sharpest, researchers said. However, the inherited part of mental ability, may have weakened again since the Victorian era, they said.

Experts have argued that the genes driving intelligence may have become less common since the 19th century as advances in medicine and nutrition have allowed people with lower IQs to have more children who survived into adulthood.