Early stone tools developed by our species Homo sapiens were no more sophisticated than those used by our extinct relatives the Neanderthals.
That is the conclusion of researchers who recreated and compared tools used by these ancient human groups.
The findings cast doubt on suggestions that more advanced stone technologies gave modern humans a competitive edge over the Neanderthals.
The work by a US-British team appears in the Journal of Human Evolution.
The researchers recreated wide stone tools called "flakes", which were used by both Neanderthals and early modern humans.
They also reconstructed "blades" - a narrower stone tool later adopted by Homo sapiens.
Some archaeologists often use the development of stone blades and their assumed efficiency as evidence for the superior intellect of our species.
The team analysed the data to compare the number of tools produced, how much cutting edge was created, the efficiency in consuming raw material and how long tools lasted.
They found no statistical difference in the efficiency of the two stone technologies.
In some respects, the flakes favoured by Neanderthals were even more efficient than the blades adopted by modern humans.
Pros and cons
The result casts doubt on the idea that blades were a significant technological advance, helping our ancestors out-compete, and eventually eradicate, their evolutionary cousins the Neanderthals.
The Neanderthals (Homo neanderthalensis) appear in the fossil record about 400,000 years ago.
At their peak, these squat, physically powerful hunters dominated a wide area spanning Britain and Iberia in the west, Israel in the south and Siberia in the east.
Meanwhile, Homo sapiens evolved in Africa, and displaced the Neanderthals after spreading into Europe about 40,000 years ago.
The last known evidence of Neanderthals comes from Gibraltar and is dated to between 28,000 and 24,000 years ago.
Lead author Metin Eren, from the University of Exeter, UK, said: "Technologically speaking, there is no clear advantage of one tool over the other.
"When we think of Neanderthals, we need to stop thinking in terms of 'stupid' or 'less advanced' and more in terms of 'different'."
He added: "Our research disputes a major pillar holding up the long-held assumption that Homo sapiens was more advanced than Neanderthals.
"It is time for archaeologists to start searching for other reasons why Neanderthals became extinct while our ancestors survived."
Professor Chris Stringer, head of human origins at London's Natural History Museum, said: "There are now very few palaeoanthropologists who consider the Neanderthals to have been 'stupid', or who consider that they died out because they made flake rather than blade tools."
Professor Stringer, who was not connected with the study, added: "We know that the Neanderthals were very capable technicians, and that their tools would have been excellent for activities such as butchery, working skins or wood.
"However, the blade tools manufactured by early modern humans in Europe were often modified for specialisation as piercers, chisels or engravers, and as parts of composite tools, such as harpoons.
"With modern humans we not only find a greater variety of tools, but also much greater working of difficult materials like bone, antler and ivory."
The authors of the paper in Journal of Human Evolution suggest that, since they conferred no technological advantage, modern humans may have used blades because they had cultural meaning.
"For early Homo sapiens colonizing Ice Age Europe, a new shared and flashy-looking technology might serve as one form of social glue by which larger social networks were bonded," said Mr Eren.