Humans
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The last Neanderthals lived in Western Europe but disappeared within a few thousand years of the arrival of modern humans. The fact that we so rapidly replaced these archaic hominins has been used to support the theory that our superior cognitive abilities allowed us to outcompete them, yet new research shatters this idea by suggesting that Neanderthals were in fact just as brainy as we are.
The rest of this article is behind a paywall. Please sign in or subscribe to access the full content.Understanding the limits of Neanderthal cognition is tricky, as soft tissue tends not to survive for long, which means we´ve never actually seen a brain belonging to a Pleistocene hominin. However, from the skulls we've found, it seems as though Neanderthal brains were probably slightly different in shape to ours.
For instance, the Neanderthal braincase is typically more elongated than the globular noggin we wear today. Some researchers have therefore suggested that our extinct cousins may have had smaller cerebellar hemispheres than us, and that this may have limited their language processing abilities, executive function, working memory, and cognitive flexibility.
According to the authors of a new study, however, this probably wasn’t the case. After comparing the brain volumes of modern-day white Americans with ethnic Han Chinese individuals, the researchers found that the estimated differences between Neanderthal and Homo sapiens brains fall within the range of variation displayed by different human populations today.
In fact, for nine of the 13 brain regions they examined, the study authors found a greater degree of difference between the present-day cohorts in the US and China than between Neanderthals and prehistoric modern humans. “This suggests that cognitive differences between Neanderthals and [modern humans] would have comfortably fit within the range found among modern human populations – which are generally not considered evolutionarily significant,” write the researchers.
Even if our species did benefit from a tiny degree of cognitive superiority, it’s highly unlikely that such a small advantage could have resulted in the complete replacement of Neanderthals in just a few millennia. Across Europe, the two hominin lineages are estimated to have co-existed for between 2,600 and 5,400 years, which is not enough time for one organism to annihilate another without a significant evolutionary edge.
“This undermines the suggestion that Neanderthal replacement occurred because of cognitive limitations,” explain the study authors.
To bolster this claim, the researchers highlight a series of recent discoveries hinting at complex cognition and a high level of intelligence in Neanderthals. Cave paintings, ritual structures, and ornamentation, for example, all point towards a capacity for abstract and symbolic thought in this extinct hominin, indicating that they may have shared many of our defining human traits.
According to the researchers, the surprisingly speedy disappearance of the Neanderthals can’t therefore be blamed on stupidity. Instead, they suggest that their small population size may have resulted in Neanderthals being overrun by modern humans, who essentially swamped the Eurasian gene pool with Homo sapiens DNA, resulting in the genetic absorption of our close relatives.
The study is published in the Proceedings of the National Academy of Sciences.
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