Neanderthals, an extinct human species, inhabited Europe and parts of Asia for hundreds of thousands of years. Their disappearance roughly 40,000 years ago, coinciding with the rise of Homo sapiens, has long fueled scientific inquiry into their intelligence and capabilities. Understanding the size and structure of the Neanderthal brain offers insights into their cognitive world and how it compared to that of our direct ancestors.
Neanderthal Brain Dimensions
Neanderthals possessed notably large brains, with endocranial volumes often exceeding modern human averages. Male Neanderthals had an average cranial capacity of approximately 1640 cubic centimeters (cm³), while females averaged around 1460 cm³. This places their average brain size within, and sometimes above, the range observed in modern Homo sapiens. For comparison, the average cranial capacity for modern Homo sapiens ranges from about 1300 to 1500 cm³, though individual volumes can vary widely, from 950 to 1800 cm³.
While the absolute size of Neanderthal brains was considerable, this is considered in relation to their robust body build. Neanderthals were more heavily muscled and stockier than modern humans. A larger body requires a larger brain to manage basic bodily functions and sensory processing. Some analyses suggest that when adjusted for their larger body mass, the functional brain capacity available for other cognitive tasks in Neanderthals might have been smaller than in early Homo sapiens.
Implications for Cognitive Abilities
The large brain size of Neanderthals initially suggested a level of intelligence comparable to modern humans, but the relationship between brain volume and cognitive ability is complex. Having a larger brain does not directly translate to superior intelligence. Archaeological records indicate that Neanderthals engaged in behaviors similar to early Homo sapiens, including sophisticated hunting strategies, foraging, and tool manufacturing. Their Mousterian stone tool industry demonstrates skill.
Evidence also suggests Neanderthals possessing some capacity for symbolic and abstract thinking. This includes findings of ornaments made from bird claws and feathers, collections of objects like crystals, and engravings, though interpretations remain debated. Regarding language, anatomical features suggest potential speech adaptations, and genetic studies indicate they shared some language-relevant genes with modern humans. Researchers believe Neanderthals had a form of language, possibly a protolanguage or gestural communication.
Beyond Raw Size: Brain Organization
Beyond overall volume, Brain organization and development distinguish Neanderthals from modern humans. Neanderthal brains were characterized by a more elongated shape, with flatter parietal and cerebellar regions. In contrast, modern human brains exhibit a more globular shape, developing through a unique postnatal “globularization” phase absent in Neanderthals.
Modern humans possess taller, more extended, and dorsally rounded parietal lobes, with larger surface areas in regions associated with complex cognitive functions like visuospatial integration, tool use, and language processing. The cerebellum, involved in cognitive flexibility, attention, language, and memory, was also larger in early Homo sapiens compared to Neanderthals. These structural differences suggest varying cognitive processing capacities between the two species. A specific variant of the TKTL1 gene in modern humans leads to greater neurogenesis, particularly in the frontal neocortex, implying that modern humans developed more neurons in this region than Neanderthals. Neanderthals also had larger visual systems, meaning a greater proportion of their brain was dedicated to visual processing, potentially leaving less neural tissue for other cognitive functions.