Humans have been getting less intelligent since Victorian times, according to a controversial new study.
The research claims that up until 180 years ago, people were getting smarter thanks to natural selection favouring "survival of the sharpest".
The emergence of modern day techniques of farming, cities and government would have made it easier for smarter people to get further in life, have more children and spread their genetic code more widely.
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But that trend has now being reversed, according to scientists in Brussels.
"Genes driving intelligence have become less common since Victorian times, because advances in medicine and nutrition means people with lower IQs can have more children that survive into adulthood," explains the MailOnline.
In order to test their theory an international team led by Michael Woodley, of the Free University in Brussels, 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 seventh century AD.
Comparing these against the DNA of 503 modern Europeans, the researchers found that the mutations linked to higher general cognitive ability - which enables people to solve problems across a range of different modes of thinking - had become more common as time went by.
This general increase in intelligence is counter-balanced by a dip since the 20th century - "meaning that although people on average have higher IQs they have decreased since Victorian times when we were in our prime," says the MailOnline.
The researchers' results were "confirmed in a separate analysis of the genes of 66 more ancient people who had lived across 3,200 years," says The Times.
"Their conclusions are likely to be hotly disputed," adds the paper. "The extent to which humans are still subject to the same evolutionary pressures that Darwin saw in the animals of the Galapagos is moot."
Neil Pendleton, professor of medical gerontology at the University of Manchester, who has previously worked on the genetics of human intelligence, told the paper that the findings were an "interesting observation".
"The methods are acceptable and the proposal has some evidence: that if the same common genetic variance we can detect for modern humans had the same effect in early figures, then it would seem there is an enrichment for these in the historical period transition," he said.
