The term “caveman” is a broad and often misleading label used to describe various groups of early humans and hominins, spanning from Homo erectus hundreds of thousands of years ago to Neanderthals and early Homo sapiens of the Paleolithic era. Determining a definitive lifespan for these groups is challenging, but anthropological evidence indicates a consistent pattern across this vast period. The average lifespan of early humans was significantly shorter than it is today, primarily due to high mortality in the earliest years of life. However, the potential maximum lifespan for an individual who survived the perils of childhood was not dramatically different from a modern human’s potential.
Defining the Early Human Lifespan
The statistical average of how long a Paleolithic person lived, known as life expectancy at birth, was remarkably low, typically falling in the range of 25 to 40 years. This figure is a statistical reality derived from skeletal remains, but it does not mean that most people died in their thirties. The calculation of life expectancy at birth is heavily skewed by the extremely high rates of infant and child mortality, where a large percentage of the population died before reaching age five or ten.
The demographic picture changes significantly when calculating the life expectancy of an individual who successfully navigated the most dangerous years of childhood. For those who survived infancy, life expectancy often jumped to an additional 40 or 50 years, meaning that reaching an age of 50 or 60 was a common outcome for adults. The presence of older individuals in the fossil record, including some Neanderthals and early Homo sapiens who lived into their sixties, confirms that human biology was capable of long life even in prehistoric times.
Determining Age in the Fossil Record
Scientists estimate the age of deceased hominins by analyzing the developmental and degenerative changes preserved in their skeletal and dental remains. For non-adults, the process is quite precise, relying on the predictable schedule of tooth formation and eruption, which provides a chronological timetable for the first two decades of life. The tough enamel coating of teeth makes them excellent artifacts for study, often outlasting other bone structures.
In adult remains, age estimation shifts from observing growth to measuring physical wear and degeneration. A primary method involves analyzing dental wear patterns, where the degree of attrition on the chewing surfaces is compared to established rates of wear within a population. Additionally, the continuous, age-related formation of secondary dentin inside the tooth causes the pulp cavity to shrink, and the measurement of this reduction provides an estimate of the individual’s chronological age.
Beyond the teeth, anthropologists use histological analysis, which involves examining the microscopic structure of bone tissue under a microscope. As the skeleton constantly remodels itself throughout life, new cylindrical structures called secondary osteons replace older bone. By counting the density of these osteons and measuring the diameter of their central canals in a cross-section of bone, researchers can apply regression formulas to estimate the age at death. While less reliable due to individual variability, the degree of fusion in the cranial sutures, the seams between the bones of the skull, can also offer a broad indicator of age.
Primary Factors Limiting Longevity
The primary reason the average lifespan was so short was the constant, intense pressure from environmental and biological hazards that led to high mortality rates at every stage of life. Acute infectious disease was a major killer, estimated to be responsible for the majority of deaths in Paleolithic populations. The nomadic lifestyle of hunter-gatherers generally limited large-scale epidemics, but pathogens like Corynebacterium diphtheriae have been identified in Mesolithic remains, suggesting early exposure to bacterial threats.
The transition to more settled living later in the Paleolithic era led to increased population density and closer contact with animal populations, dramatically increasing the risk of zoonotic diseases. Pathogens like Yersinia pestis and Salmonella enterica began to emerge as significant threats, often spreading through contaminated food, water, or close interpersonal contact. Lack of sanitation, especially in early settlements, meant that even minor infections could rapidly become fatal without modern medicine.
Physical trauma and violence also substantially limited longevity for both Neanderthals and early Homo sapiens. Skeletal evidence shows high rates of healed and unhealed fractures, often attributed to close-range hunting of large, dangerous prey. Furthermore, both groups exhibited similar levels of head trauma, suggesting that inter-personal conflict or accidents were a persistent reality.
The reproductive process presented a unique and profound risk to the population average, particularly for females and infants. Studies of contemporary hunter-gatherer societies indicate a high infant mortality rate, often around 25 to 30 percent, where one in four children did not survive their first year. Childbirth itself carried a significant maternal mortality risk, with estimates suggesting 1 to 2 percent of pregnancies resulted in the mother’s death.