Estimates for the “average lifespan” of prehistoric humans typically land somewhere around 30 to 35 years, but that number is profoundly misleading. It reflects life expectancy at birth, a statistic hammered down by staggering rates of infant and child death. A prehistoric adult who survived past childhood could reasonably expect to live into their 60s or even 70s, a range not radically different from early modern populations before antibiotics. The real story of how long “cavemen” lived is less about a single number and more about which risks you managed to dodge, and at what age.
Why the “Average” Hides More Than It Reveals
When researchers talk about average lifespan in past populations, they usually mean life expectancy at birth. This is a mathematical average that includes everyone born, whether they lived to 80 or died at two days old. In populations with extremely high infant mortality, this number plummets even if plenty of adults are walking around in their 60s.
A large cross-cultural analysis of both hunter-gatherer and historical populations estimated that roughly 27% of infants did not survive their first year and approximately 47.5% of all children failed to reach puberty.1Evolution and Human Behavior. Infant and child death in the human environment of evolutionary adaptation When nearly half of all people born die before adulthood, the “average” lifespan collapses to a number that makes it sound like no one got old. But people absolutely did. The average is doing math, not describing a typical adult’s experience.
Think of it this way: if ten people are born and five die before age five, while the other five live to 70, the average lifespan of the group is about 37. That is technically accurate, but it tells you nothing useful about either the children who died or the adults who lived long lives. The number erases both realities.
How Long Could a Prehistoric Adult Actually Live?
The best window into prehistoric lifespans comes from modern hunter-gatherer societies, groups living without agriculture, modern medicine, or industrialized food systems. Their mortality patterns are the closest analogue we have to what life looked like for most of human history.
A major cross-cultural study of hunter-gatherer and small-scale horticultural populations from around the world argued for an adaptive human lifespan of 68 to 78 years.2Population and Development Review. Longevity Among Hunter‐Gatherers: A Cross‐Cultural Examination In these groups, once you cleared childhood, you had a decent shot at reaching old age. Modal age at death for adults who survived to age 15 often fell in the late 60s to early 70s. These are people without hospitals, antibiotics, or nutritional supplements, living lives of physical labor and periodic food scarcity.
That said, not every hunter-gatherer group fits neatly into this picture. Mortality data from the Hiwi hunter-gatherers of Venezuela, for instance, show comparatively high adult death rates. The researchers who published those data suggested that the Hiwi, with their high levels of violence and adult mortality, may actually represent Paleolithic demographics more accurately than the lower, disease-based death rates found in the more frequently cited forager studies.3PubMed. High adult mortality among Hiwi hunter-gatherers: implications for human evolution In other words, the optimistic 68-to-78-year range may reflect the best-case scenario for foragers. Real prehistoric adults, facing more predation and interpersonal conflict, may have had it rougher.
Research comparing hunter-gatherer mortality to both chimpanzees and modern low-mortality populations found that the difference in survival between hunter-gatherers and people in today’s safest countries is actually greater than the difference between hunter-gatherers and wild chimpanzees.4PubMed Central. Human mortality improvement in evolutionary context That puts into perspective just how much modern medicine, sanitation, and nutrition have changed the game.
What Actually Killed People in Prehistory
The leading cause of death for most of human prehistory was infection. This held true for both wild chimpanzees and traditional forager-farmers who lacked access to modern medicine.5PubMed Central. Evolution of the human lifespan and diseases of aging: roles of infection, inflammation, and nutrition Respiratory illness, gastrointestinal infections, wound infections, and parasites were constant threats. A scratch from a thorn or a broken bone could spiral into a fatal infection. Without antibiotics, even minor injuries carried real risk.
Hunter-gatherer populations were generally too small and too mobile to sustain epidemic diseases like smallpox, measles, or cholera, which require large, dense populations. But they faced heavy parasite loads and chronic infections that wore people down over time. The diseases of prehistory were different in character from the plagues that later ravaged agricultural civilizations, but no less deadly on an individual level.
Violence also played a role, and likely a bigger one than sanitized popular narratives suggest. The earliest direct evidence of lethal interpersonal violence in the fossil record comes from Cranium 17 at the Sima de los Huesos site in Spain, dated to the Middle Pleistocene. That skull shows two perimortem depression fractures on the frontal bone, interpreted as being produced by two separate blows of localized blunt force trauma.6PubMed Central. Lethal interpersonal violence in the Middle Pleistocene This was not a fall or an animal attack. Someone killed this person.
Childbirth was another significant risk. Maternal and fetal death were intertwined with poor environmental conditions, malnutrition, high rates of infectious disease, and the absence of any obstetric care.7PubMed. Lucy’s fatal childbirth? About materno-foetal mortality in the ancient times The relatively small number of archaeological cases of maternal death with fetal remains may reflect underrepresentation in the fossil record rather than low rates of obstetric mortality.
How Scientists Estimate Age from Ancient Bones
When you see a headline claiming a Neanderthal died at 40 or a Paleolithic woman lived to 55, those numbers come from reading biological clues in skeletal remains. But the methods are far from perfect, and their limitations directly shape how we understand prehistoric lifespans.
One of the more reliable techniques involves counting growth rings in tooth cementum, a hard tissue that covers tooth roots. Like tree rings, layers of cementum are deposited annually. By counting these layers and adding the eruption age of the tooth, researchers can estimate how old someone was when they died.8PubMed Central. Quantitative analysis of dental age estimation by incremental line of cementum Studies have found this method to be reasonably accurate, with cementum annulations considered more reliable for adult age estimation than many other skeletal traits.9PubMed Central. Human age estimation from tooth cementum and dentin This approach is especially useful for poorly preserved skeletons where other age markers have deteriorated.10PubMed. Assessing the application of tooth cementum annulation relative to macroscopic aging techniques in an archeological sample
But here is the catch: the more common macroscopic methods, those based on visible wear on joints, skull sutures, and the pelvis, have a persistent tendency to underestimate the age of older adults. People who died past 50 are routinely classified as younger than they actually were. This means that published studies of archaeological skeletons almost certainly undercount older individuals.11PubMed. Paleodemography: From archaeology and skeletal age estimation to life in the past If your aging method has trouble distinguishing a 55-year-old skeleton from a 45-year-old one, your demographic profiles will make it look like fewer people lived past middle age than actually did.
There is also a deeper conceptual problem called the Osteological Paradox, a challenge first articulated in the early 1990s that fundamentally changed how bioarchaeologists interpret their data.12PubMed Central. From Optimism to Opportunity: New Perspectives on the Osteological Paradox The paradox points out that the skeletons available for study are, by definition, the people who died. They do not represent the living population. A skeleton showing signs of chronic disease might actually belong to someone who was relatively resilient, since they survived long enough for the disease to leave marks on bone. Someone who died quickly from the same illness might leave a perfectly healthy-looking skeleton. This makes it surprisingly tricky to infer population-level health from a cemetery.13Journal of Archaeological Research. The Osteological Paradox 20 Years Later: Past Perspectives, Future Directions
On top of all this, children’s bones are small and fragile, and they decompose more readily than adult bones. Studies of skeletal preservation in medieval cemeteries have found specific patterns of preservation loss for non-adult remains, though very young children under two were sometimes less affected by decomposition than older children. The broader pattern means that infants and children are chronically underrepresented in the archaeological record, which biases any mortality profiles we try to reconstruct.
The Longevity Leap of Early Modern Humans
Not all periods of prehistory were equal when it came to how long people lived. One of the more striking findings in paleodemography is that adult survivorship increased dramatically when anatomically modern humans entered the Early Upper Paleolithic, roughly 30,000 to 40,000 years ago. A study comparing the ratio of older to younger adults across successive time periods, using dental wear as the aging method, found a significant increase in longevity at each stage but a particularly dramatic jump among Early Upper Paleolithic modern humans.14PubMed Central. Older age becomes common late in human evolution The researchers argued that this increase in the number of older adults contributed to the population expansions and cultural innovations we associate with behavioral modernity: complex art, long-distance trade networks, and more sophisticated tool technologies.
More old people means more accumulated knowledge in a group. Elders can teach skills, remember where food and water sources are during droughts, mediate conflicts, and care for grandchildren. The link between living longer and cultural complexity is not just correlation. A population with more multi-generational overlap has more capacity for the kind of social learning that drives innovation.
Neanderthals and Close Relatives
Neanderthals are the prehistoric humans most people picture when they hear “caveman,” so it is worth asking how their lifespans compared. Dental evidence shows that most Neanderthal tooth crowns grew more rapidly than modern human teeth, resulting in faster dental maturation, which suggests a somewhat accelerated developmental timeline compared to us.15PubMed Central. Dental evidence for ontogenetic differences between modern humans and Neanderthals Faster development does not automatically mean shorter lifespan, but it is consistent with a life history shaped by higher mortality pressure.
A genomic study that used DNA methylation patterns to predict lifespan in vertebrates estimated that both Neanderthals and Denisovans had a maximum lifespan of about 38 years. The study’s authors noted this was similar to their estimate for early modern humans. That number should not be confused with the adaptive lifespan of 68 to 78 years documented in living hunter-gatherers. The genomic estimate reflects a biological ceiling prediction based on DNA patterns, while the hunter-gatherer data reflects observed mortality in real populations. The two measurements are answering different questions, and the gap between them is a reminder of how much context matters when citing a single lifespan figure.
Did Farming Make Things Better?
One of the more counterintuitive findings in this area is that the shift from hunting and gathering to agriculture, the Neolithic Revolution starting roughly 10,000 to 12,000 years ago, did not immediately improve health or longevity. In many cases, it made things worse. A broad review of bioarchaeological evidence found that adult stature decreased as reliance on agriculture increased, and this pattern held across the entire globe regardless of when or where farming was adopted.16PubMed. Stature and robusticity during the agricultural transition: evidence from the bioarchaeological record
More detailed skeletal analysis from Central and Southeast Europe documented significantly reduced mean stature and body mass in Neolithic agriculturalists compared to the Late Mesolithic hunter-gatherer-fishers who preceded them. The growth impairment was particularly pronounced among women.17PLOS ONE. Early Life Conditions and Physiological Stress following the Transition to Farming in Central/Southeast Europe: Skeletal Growth Impairment and 6000 Years of Gradual Recovery Early farmers ate a narrower diet, relied heavily on cereals with less animal protein, worked their bodies harder through repetitive agricultural labor, and lived in larger, denser settlements where infectious diseases could spread more easily. It took thousands of years of gradual recovery before farming populations regained the stature and physical robustness of their foraging ancestors.
So the popular narrative that human civilization marched steadily toward longer, healthier lives is wrong in its details. The move from foraging to farming was, for many generations, a step backward in terms of individual health. The advantage of agriculture was demographic: it supported larger populations, even if those populations were shorter, sicker, and more stressed.
Why Humans Evolved to Live Past Reproduction
Most mammals die not long after their reproductive years end. Humans are unusual in that women commonly live decades past menopause. One influential explanation for this is the grandmother hypothesis, which proposes that women who remained vigorous beyond their fertile years enhanced their own genetic legacy by helping to care for grandchildren.18PubMed Central. The grandmother effect: implications for studies on aging and cognition By providing food and care, grandmothers allowed their daughters to resume reproducing sooner, increasing overall family fertility. Over evolutionary time, genes promoting post-reproductive longevity would have been favored.19PubMed. Grandmothering, menopause, and the evolution of human life histories
This hypothesis does more than explain menopause. It helps explain the entire shape of the human life history: our late maturity compared to other primates, our small size at weaning, and our relatively high fertility. If grandmothering drove the evolution of longer lifespans, then old age is not a modern luxury. It is an adaptive feature of our species, shaped by natural selection over hundreds of thousands of years.20PubMed. Grandmothers and the evolution of human longevity: a review of findings and future directions
Care for the Disabled and Elderly in Prehistory
Perhaps the most vivid evidence that prehistoric people lived long enough to be genuinely old, and were valued when they got there, comes from the archaeological record of caregiving. Between 3,700 and 4,000 years ago in northern Vietnam, a young man survived for approximately ten years with disabilities so severe he would have required help with every aspect of daily living. Paralyzed from at least the waist down, with very limited upper body mobility, this individual, known as Man Bac Burial 9, lived with what was at minimum paraplegia and possibly quadriplegia from childhood into his third decade. In a subsistence Neolithic economy with no medical technology, his survival was only possible because other people chose to keep him alive, fed, clean, and socially integrated for a full decade.
Cases like this are not one-off curiosities. The archaeological record contains numerous examples of individuals who survived serious injuries, lost limbs, or lived with conditions that would have required sustained assistance. These cases tell us something important: prehistoric communities were not indifferent to their vulnerable members. Social bonds, cooperation, and deliberate caregiving were features of human life long before written history, and they contributed directly to extending individual lifespans beyond what raw biology might have allowed.