Modern human babies are essentially learning machines. After birth, their brains grow in leaps and bounds, allowing infants to lay the groundwork for future social and cognitive achievement. But it wasn’t that way for Neandertals. At least in terms of the shape of their brains, Neandertal newborns pretty much coasted into adulthood.
Scientists have shown that Neandertal brains are about the same size as ours. Yet our Paleolithic brethren are not known for having been great scholars. To probe this cognitive conundrum, researchers took CT scans of 11 Neandertal brains, including one newborn. And they compared these images to those of modern humans.
They found that baby braincases are similar in size and shape, regardless of their parentage. All are elongated, most likely to smooth passage through the birth canal. But modern human baby brains grow more globular in the first year of life, changes that reflect a massive wave of neural development. That phase change is absent in Neandertals, whose brains retain that extended newborn shape throughout their lives. The results appear in the journal Current Biology. [Philipp Gunz et al., "Brain development after birth differs between Neanderthals and modern humans"]
It’s not clear whether our well-rounded brains made us the pointy-headed intellectuals we are today. But they do make us look smart in a cap and gown.
[The above text is an exact transcript of this podcast.]