Archimedes could string a number or two together and Homer was fairly handy with a hexameter, but on the whole their contemporaries were probably a little less intelligent than people today, according to a controversial study.
Mankind has evolved to become slightly brighter over the past few millennia thanks to circumstances that have favoured the survival of the sharpest, researchers argue.
We should not get too smug, though. The inherited part of mental ability — which accounts for roughly half of the difference between individuals — may well have weakened again since the Victorian era, the academics say.
An international team led by Michael Woodley, of the Free University in Brussels, claims that the emergence of farming, cities and systems of government would have made it easier for smooth operators such as Odysseus to pass on their genes than for muscle-bound plodders such as Ajax.
Even if the decks were very marginally stacked towards clever people having more children than stupid people, over many centuries this effect might add up to a shift in population-level genetics.
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To test their idea, Dr Woodley and his colleagues used a bank of genomes recovered from the remains of 99 people from central and eastern Europe.
The oldest of these died in about 2,000BC, at the start of the Bronze Age, 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 (GCA), which enables people to solve problems across a range of different modes of thinking, 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.
Dr Woodley has previously 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.
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As a result, his team suggests that the “millennia-long microevolutionary trend favouring higher GCA” may have gone into reverse over the course of the 20th century.
Their conclusions are likely to be hotly disputed. The extent to which humans are still subject to the same evolutionary pressures that Darwin saw in the animals of the Galapagos is moot.
While some mutations, such as the lactase persistence gene, which allows us to drink milk and eat cheese in adulthood, have spread widely over the past 10,000 years, there are relatively few such clear-cut examples — especially in the field of intelligence, which is influenced in a small way by many hundreds of genes.
Dr Woodley and another of the paper’s four authors have backgrounds in plant biology, while a third, Davide Piffer, has previously asserted that Africans are genetically disposed to have lower IQs than Europeans. The paper, which was released on bioRxiv, a website for early-stage research, has yet to be published in a peer-reviewed journal.
Neil Pendleton, professor of medical gerontology at the University of Manchester, who has previously worked on the genetics of human intelligence but was not involved in this study, said that the findings were an “interesting observation”.
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“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.
James Thompson, honorary senior lecturer in psychology at University College London, said that the study appeared to show a long-term upward movement in the biological basis for intelligence, although it was not yet clear how big the difference had been.
“If we had been caught in our Victorian prime, our rise in ability since the pre-agricultural, hunter-gatherer ages would have been even more apparent,” he wrote in a blog post.
“Selection is the key. When you must use your wits to survive, and restrain present urges for future gains, then the brighter multiply. When, in less taxing circumstances, there is no particular need for wit or restraint, then there is no premium for those characteristics.”