Without written records, the intimate lives of our Stone Age ancestors are a subject of scientific inquiry. Researchers employ a range of methods to understand prehistoric sexuality, examining fossils, analyzing ancient DNA, and studying archaeological artifacts. This work provides glimpses into the complex social and sexual landscapes of populations that existed tens of thousands of years ago.
Prehistoric Mating Systems
How Stone Age people formed partnerships is a topic of scientific debate. One line of evidence comes from the fossil record and sexual dimorphism—the size difference between males and females. A significant size disparity often suggests intense male competition for mates, which can indicate a polygynous system. A decline in sexual dimorphism starting with early Homo suggests a shift away from such competition.
By comparing early human fossils to modern hunter-gatherer societies and non-human primates, researchers infer potential social structures. Evidence from contemporary foraging groups, used as analogs, shows a wide variety of arrangements. Studies of these societies show arranged marriages were common, and most men had only one wife, suggesting low levels of polygyny. This has led to the theory that early humans engaged in various strategies, from serial monogamy to small-scale polygyny.
These arrangements were not random and were likely regulated as part of a sophisticated social system. Research on the 34,000-year-old remains from Sunghir, Russia, indicates that early modern humans deliberately sought partners from outside their kin group. This practice of finding mates from a wider social network was necessary to avoid inbreeding. The complexity of these networks suggests our ancestors understood the benefits of genetic diversity.
Evidence of Inter-Species Encounters
Genetic analysis has provided proof of sexual encounters between different hominin species. The sequencing of Neanderthal and Denisovan genomes revealed that their DNA is present in modern human populations outside of Africa. This genetic legacy is a result of interbreeding events as anatomically modern humans migrated out of Africa and into Eurasia.
The amount of archaic DNA varies among modern populations. People of non-African descent have genomes that are between 1.5% and 2.1% Neanderthal. Denisovan DNA is found in some Asian and Oceanic populations, with the highest concentrations, up to 6%, in Melanesians and Philippine Negritos. These genetic markers help scientists trace ancient migration routes and interaction zones.
The gene flow was not a one-way street. Evidence also points to interbreeding between Neanderthals and Denisovans. Furthermore, both of these archaic groups interbred with an older, ‘superarchaic’ hominin population that had split from the human lineage around two million years ago. These discoveries paint a picture of a Stone Age world populated by multiple human-like groups that interacted.
Sex for More Than Procreation
The role of sex in the Stone Age likely extended beyond reproduction, serving important social functions. Comparisons with our close primate relatives, the bonobos, offer a model for this idea. Bonobos use sexual interactions, including same-sex encounters, to build alliances, resolve conflicts, and reduce social tension. This suggests sex as a tool for social bonding may have been present in our own lineage.
Archaeological finds, such as the ‘Venus figurines’ from the Upper Paleolithic, have sparked debate about their purpose. These small, stylized female figures with exaggerated features are found across Eurasia. Interpretations of their meaning are varied; they have been described as fertility symbols, religious icons, prehistoric erotica, or even self-portraits created by women.
While their exact function remains speculative, these artifacts indicate that human sexuality has long been imbued with symbolic meaning. The figurines suggest that abstract thought was intertwined with concepts of the body, fertility, and desire. This points to a world where sex was part of a rich cultural and social fabric.
Reconstructing the Stone Age Family
The concept of family in the Stone Age was likely different from the nuclear family model today. Early humans lived in small, mobile hunter-gatherer bands with social units adapted for survival. Kinship ties were important, but the composition of these groups was diverse, often including unrelated individuals.
A feature of these societies was likely communal child-rearing, a practice known as alloparenting. In this system, individuals other than the biological parents, like grandparents and siblings, play an active role in caring for children. This cooperative approach distributes the costs of raising offspring, which have long childhoods and require significant investment. Foraging societies like the Efe and Aka in central Africa demonstrate this behavior.
This cooperative structure helped build resilient social networks. Divorce and remarriage were common in many forager groups, meaning children often lived in households with step-parents and a mix of relatives. This fluid and communal family structure was a successful strategy that endured for much of human history.