Neanderthals were stocky, powerfully built humans with wide bodies, short limbs, and elongated skulls that housed brains as large as ours. Their faces jutted forward with prominent brow ridges, large noses, and robust jaws, giving them a look that was unmistakably human yet strikingly different from any living population. Thanks to decades of skeletal analysis and, more recently, ancient DNA work, we now have a surprisingly detailed portrait of these close relatives, down to the likely range of their skin tones and the architecture of their inner ears.
The Skull and Brain Case
The Neanderthal skull is one of the most recognizable shapes in human evolution. Viewed from the side, the braincase is long and low, stretching back rather than rising upward into the globe shape typical of our own species.1Current Biology. Brain development after birth differs between Neanderthals and modern humans A pronounced bulge at the back of the skull, sometimes called an occipital bun, gives it a distinctive elongated profile. Above the eyes, a continuous ridge of bone, the supraorbital torus, forms a shelf that modern humans simply do not have. The forehead slopes back rather than rising vertically, and the midface projects forward so that the nose and cheekbones sit farther ahead of the eye sockets than in any living human population.
Despite the different packaging, the brain inside was comparable in volume to ours, and at birth Neanderthal brain size was similar to that of modern human newborns. The key difference was timing: Neanderthal brain growth rates during early infancy appear to have been higher, ultimately producing slightly larger adult brains without necessarily finishing development any sooner.2PubMed Central. Neanderthal brain size at birth provides insights into the evolution of human life history The internal organization differed too. A larger share of neural real estate seems to have been devoted to vision, a point worth exploring separately.
Eyes Built for Seeing
Neanderthal eye sockets were large, noticeably bigger than those of contemporary modern humans. This is not just a quirk of skull shape: the orbital volume correlates with the size of the visual system, and analysis of Neanderthal crania shows they had significantly larger visual systems than the modern humans living at the same time.3PubMed Central. New insights into differences in brain organization between Neanderthals and anatomically modern humans When researchers accounted for both this expanded visual hardware and the Neanderthals’ greater body mass, the remaining brain volume available for other cognitive tasks was actually smaller than in our species.
Endocast studies of Neanderthal occipital bones support this picture from the brain side. The primary visual cortex, the region at the back of the brain that processes raw visual input, appears to have been larger in Neanderthals than in modern humans. Researchers studying specimens from the El Sidrón site in Spain found that the calcarine sulcus, the groove closely associated with this cortex, was long and deeply incised, suggesting an expanded visual processing area that could have given Neanderthals relatively greater visual acuity.4PubMed Central. Primary visual cortex in neandertals as revealed from the occipital remains from the El Sidrón site, with emphasis on the new SD‐2300 specimen In Europe’s high-latitude environments, with long winters and low light, sharper vision would have been a real advantage. The trade-off, less brain devoted to social or planning functions, has fueled debate about whether Neanderthals maintained smaller social networks than our ancestors, though that interpretation is contested.
A Face Designed for Cold
The Neanderthal face was wide, with broad cheekbones that swept backward and a nasal aperture much bigger than what you see in most modern humans. That large nose was not just cosmetic. Airflow simulations comparing Neanderthal nasal passages with those of modern humans from different populations found that Neanderthals conditioned inhaled air (warming and humidifying it) with an efficiency adapted to cold, dry climates, performing comparably to modern Asian populations that have independently evolved effective nasal air conditioning.5PubMed Central. Nasal airflow simulations suggest convergent adaptation in Neanderthals and modern humans In other words, Neanderthal and modern human noses appear to have converged on a similar solution to the same environmental problem, arriving there from quite different starting anatomy.
Below the nose, the lower face was dominated by a large jaw with no chin. The absence of a chin is one of the easiest Neanderthal identifiers: modern humans are the only living primates that have one. Neanderthal mandibles were thick and heavily built, with a gap behind the last molar, called the retromolar space, where the jaw continues past the wisdom teeth. This combination of projecting midface and chinless jaw gave Neanderthals a profile that slopes forward from the brow to the mouth in a way that looks alien compared to the flat faces of living humans.
Teeth That Tell Stories
Neanderthal teeth were distinctive in multiple ways. Their incisors were large and shovel-shaped, with raised edges on the tongue side. Premolars had unusually complex biting surfaces, and the lower premolars had asymmetrical outlines. Perhaps most characteristic were the molars, which frequently displayed enlarged pulp chambers, a condition sometimes called taurodontism, or “bull-toothed” roots, along with features like an anterior fovea bordered by a mid-trigonid crest on the lower molars.6PubMed Central. Exploring the biomechanics of taurodontism
The front teeth show heavy wear, and scratches on Neanderthal incisors consistently run in patterns suggesting they used their teeth as tools, clamping hides or other materials between the front teeth and pulling or cutting with a stone tool held in the other hand. This “stuff and cut” behavior left its mark on nearly every Neanderthal dental specimen with preserved anterior teeth. The enlarged pulp chambers of the molars may have been biomechanically advantageous for absorbing the stresses of heavy chewing, though researchers are still working out the exact functional implications.
Body Shape and Build
From the neck down, the Neanderthal body plan was built for power and cold tolerance. They had high body mass, broad trunks, and short limbs relative to their stature, a body shape consistent with conserving heat in cold environments.7PubMed Central. Neandertal Cold Adaptation: Technological, Anatomical, and Physiological Responses to Cold Stress in One of Our Closest Fossil Relatives The pelvis was wide, the ribcage bell-shaped and flaring outward at the bottom, and the overall impression was of a barrel-chested person built low to the ground.8PubMed. The different adaptive trajectories in Neanderthals and Homo sapiens and their implications for contemporary human physiological variation
This classic “cold-adapted” interpretation has been questioned over the years. Alternative explanations for the Neanderthal body plan include dietary demands, locomotor habits related to ambush hunting in wooded terrain, inherited ancestral body form, and even neutral evolutionary drift in small populations.8PubMed. The different adaptive trajectories in Neanderthals and Homo sapiens and their implications for contemporary human physiological variation The truth likely involves some combination. Whatever the ultimate cause, the result was a physique unlike anything you see in living humans: short-limbed and barrel-bodied even compared to Arctic-adapted modern populations such as the Inuit.
The ribcage deserves special mention. Three-dimensional reconstructions show that the adult Neanderthal thorax was shorter from top to bottom, deeper from front to back, and wider side to side compared to modern humans. This configuration appears to have been present from birth, not something that developed as individuals grew up, suggesting it was genetically hardwired rather than shaped by activity during life.9PubMed Central. Early development of the Neanderthal ribcage reveals a different body shape at birth compared to modern humans A wider, deeper chest would have accommodated larger lungs or a larger diaphragm, consistent with the high energy and oxygen demands of a heavy, muscular body in a cold environment.
How Tall Were They?
Neanderthals were not the towering brutes of older pop-culture depictions, nor were they tiny. Stature estimates based on long bones from roughly 14 males and 7 females place male height in the range of about 164 to 168 centimeters (roughly 5’5″ to 5’6″) and female height between about 152 and 156 centimeters (around 5’0″ to 5’1″).10PubMed. Body height, body mass and surface area of the Neanderthals That puts males at roughly the height of an average modern man in southern Europe or East Asia, not dramatically shorter. Their impression of heaviness came from width and muscle mass, not from being especially short.
Sexual dimorphism in body size was essentially the same as in living humans. An analysis of Neanderthal postcranial remains, using pelvic shape to determine sex where possible, found that the size difference between males and females was virtually identical to what you see in recent human populations. The same was true for limb bone robusticity: although Neanderthal limbs were more heavily built than ours overall, the ratio of male to female robustness was about the same as in modern samples.11Journal of Human Evolution. Sexual differences in Neanderthal limb bones By the Neanderthal period, the degree of physical difference between the sexes had already settled into the range we see today.
Skin, Hair, and Eye Color
For a long time, the color of Neanderthal skin and hair was pure guesswork. Ancient DNA has changed that, although the picture that emerges is not a single “Neanderthal look” but a range of variation. A 2007 study recovered a variant of the MC1R gene from two Neanderthal specimens, one from Spain and one from Italy, and found that this variant reduced the receptor’s activity to a level known to alter pigmentation in living humans, suggesting that at least some Neanderthals had lighter hair or skin.12PubMed. A melanocortin 1 receptor allele suggests varying pigmentation among Neanderthals
A broader analysis using genetic data from present-day Europeans confirmed and extended this finding. Neanderthal-derived DNA variants that persist in modern human genomes affect both skin tone and hair color, and here is the interesting part: different Neanderthal variants push in different directions. Some promote lighter skin and hair, others promote darker tones. This bidirectional influence suggests that Neanderthals themselves were variable in pigmentation, potentially spanning a range similar to what we see in modern Europeans.13PubMed Central. The Contribution of Neanderthals to Phenotypic Variation in Modern Humans The old museum-diorama image of uniformly dark-haired, olive-skinned Neanderthals was almost certainly too narrow. Some individuals were probably pale-skinned and red- or light-haired; others were likely darker.
Hands and Grip
Neanderthal hands were broad, with thick finger bones and wide fingertips. For decades, the robustness of their hand skeletons led researchers to assume Neanderthals relied on power grips, whole-hand squeezing rather than delicate fingertip manipulation. This assumption has not held up. Analysis of muscle attachment markings on Neanderthal hand bones found patterns that overlap exclusively with documented lifelong precision workers among modern humans, indicating that Neanderthals routinely used precise thumb-and-finger grips in their daily activities.14PubMed Central. Evidence for precision grasping in Neandertal daily activities
The anatomy of the thumb joint supports this. A three-dimensional study of the base of the first metacarpal, where the thumb meets the wrist, found that while some Neanderthal specimens differ slightly from the modern human average in joint shape, at least one well-preserved specimen (La Ferrassie I) falls within the modern human range. No significant differences exist in the locations of muscle and ligament attachments between Neanderthals and modern humans, leaving no anatomical reason to think Neanderthals could not move their thumbs and index fingers the way we do.15Nature. Manual dexterity in Neanderthals The heavy bones of the Neanderthal hand were not a limitation but a reinforcement: they could do fine work and hit hard.
Could Neanderthals Speak?
Whether Neanderthals could produce speech has been argued about since the 1970s, and the debate has centered largely on a single small bone: the hyoid, a horseshoe-shaped bone in the throat that anchors the muscles of the tongue, larynx, and pharynx. Early attempts to reconstruct the Neanderthal vocal tract positioned the hyoid bone unusually high, which would have limited the range of sounds they could produce. But that reconstruction was later challenged on the grounds that the hyoid had been placed in a position unlike that of any known human or chimpanzee, newborn or adult.16PubMed. Comparative anatomy of the larynx in man and the chimpanzee: implications for language in Neanderthal
The best-preserved Neanderthal hyoid, from the Kebara 2 burial in Israel, looks remarkably like a modern human hyoid on the outside. Micro-CT scanning revealed that its internal structure, the way the bone is reinforced internally in response to the forces it routinely bears, is also very similar to that of modern humans. Because internal architecture reflects the mechanical loads a bone experiences during life, this finding is consistent with Neanderthals having used their throats in ways similar to ours, including speech.17PubMed Central. Micro-biomechanics of the Kebara 2 hyoid and its implications for speech in Neanderthals Researchers have also attempted acoustic simulations of a reconstructed Neanderthal vocal tract to explore what sounds they could have produced.18PubMed Central. Articulatory capacity of Neanderthals, a very recent and human-like fossil hominin The consensus has shifted considerably: the claim that Neanderthals were incapable of speech is now widely regarded as unsupported by the anatomical evidence. What they said, of course, remains unknowable.
Injuries and the Wear of a Hard Life
Neanderthal skeletons tell a story of physical punishment. A high frequency of traumatic injuries and the degenerative changes that follow them have been noted across the Neanderthal fossil record.19Journal of Archaeological Science. Patterns of Trauma among the Neandertals Broken arms, healed skull fractures, damaged vertebrae, and arthritic joints appear with a regularity that suggests close-range encounters with large, dangerous animals were routine. The pattern of injuries, concentrated in the head and upper body, famously resembles that of modern rodeo cowboys, a comparison that, while somewhat tongue-in-cheek, captures the physicality of their hunting style.
A large-scale comparison of cranial trauma between Neanderthals and Upper Paleolithic modern humans found that the two groups actually suffered similar overall rates of head injuries, and in both groups males were injured more often than females.20PubMed. Similar cranial trauma prevalence among Neanderthals and Upper Palaeolithic modern humans The difference showed up in the timing: the age distribution of injuries differed between the two species, suggesting either that Neanderthals were getting hurt at different life stages than early modern humans, or that the two groups had different survival rates after being injured. Either way, the image of Neanderthals as uniquely battered compared to early modern humans living in the same periods does not quite hold up. Life in the Pleistocene was hard on everyone.
Neanderthal Features That Survive in Living People
When Neanderthals and modern humans interbred, some Neanderthal physical traits did not vanish but persisted as genetic variants in living populations. People of non-African descent carry roughly one to two percent Neanderthal DNA, and some of those inherited sequences have measurable effects on appearance. The pigmentation variants already discussed are one example. Beyond skin and hair, Neanderthal-derived genetic variation has been linked to skull shape in living people: individuals carrying a higher load of Neanderthal variants tend to have skull shapes that subtly resemble Neanderthal crania, with effects localized to the back and sides of the skull. Corresponding changes show up in the brain, particularly in the visual cortex and a region called the intraparietal sulcus.21PubMed Central. Neanderthal-Derived Genetic Variation Shapes Modern Human Cranium and Brain
Neanderthal introgression has also been tied to nose shape. A genomic region on chromosome 1 that shows strong signs of Neanderthal ancestry in Latin American populations is associated with midface height, with the Neanderthal-derived version increasing the vertical distance between certain facial landmarks. Up to about a third of chromosomes in the study sample carried Neanderthal tracts in this region.22Communications Biology. Automatic landmarking identifies new loci associated with face morphology and implicates Neanderthal introgression in human nasal shape Sleep patterns, mood tendencies, and even smoking behavior have been statistically linked to Neanderthal-derived variants, though the physical-appearance effects on skin, hair, and skull shape are the ones most directly relevant to what Neanderthals looked like.13PubMed Central. The Contribution of Neanderthals to Phenotypic Variation in Modern Humans In a sense, the Neanderthal phenotype is not entirely extinct. Fragments of it walk around in millions of people today, diluted and recombined but still detectable when you know where to look.
How Growth Shaped the Final Form
One of the more surprising findings about Neanderthal appearance is how early their distinctive body shape was established. The wider, deeper ribcage was already present in Neanderthal neonates, meaning the difference in trunk shape between Neanderthals and modern humans was set before birth, not acquired through a lifetime of different activity or diet.9PubMed Central. Early development of the Neanderthal ribcage reveals a different body shape at birth compared to modern humans The brain, by contrast, achieved its different final shape through a different growth trajectory after birth. Modern human brains undergo a distinctive “globularization” phase in the first year of life in which the braincase rounds out into its characteristic spherical shape. Neanderthal brains did not undergo this same reshaping, instead retaining the elongated form throughout development.1Current Biology. Brain development after birth differs between Neanderthals and modern humans
The combination of fast early brain growth and a prenatal body plan that was already distinctly Neanderthal means that a Neanderthal infant, while recognizably a baby, would have looked subtly different from a modern human newborn: a slightly longer head, a wider trunk, and limb proportions already trending toward the short, broad adult form. By adolescence the full suite of Neanderthal features, the brow ridge, the projecting face, the robust limbs, would have been in place, shaped by both genetic blueprint and the mechanical demands of a physically intense life.