In what is claimed to be a major breakthrough in explaining the relationship between absolute brain size and higher cognitive abilities, a team of British anthropologists has found that the reason the Neanderthals had lower cognitive skills than humans have was not because they had a smaller brain but because their brain was structured differently.
Neanderthals’ brains were similar in size to their contemporary modern counterparts but were adapted to allow them to see better and maintain larger bodies, according to the team’s research published in the Royal Society’s Journal of Biological Sciences.
Vision and movement
“Results imply that larger areas of the Neanderthal brain, compared to the modern human brain, were given over to vision and movement and this left less room for the higher level thinking required to form large social groups,” it says.
Professor Robin Dunbar and Eiluned Pearce of Oxford University and Professor Chris Stringer of the Natural History Museum looked at data from 27,000-75,000-year-old fossils and compared the skulls of 32 anatomically modern humans and 13 Neanderthals to examine brain size and organisation. They found that Neanderthals had significantly larger eyes than modern humans.
Once the differences in body and visual system size were taken into account, the researchers were able to compare how much of the brain was left over for other cognitive functions, according to the study.
“Since Neanderthals evolved at higher latitudes and also have bigger bodies than modern humans, more of the Neanderthal brain would have been dedicated to vision and body control, leaving less brain to deal with other functions like social networking,” said Prof Pearce.