Signs of Humanity
Humans 40,000 y ago developed a system of conventional signs
Christian Bentz & Ewa Dutkiewicz
Proceedings of the National Academy of Sciences, 3 March 2026
Abstract:
As humans, we store and share information. This allows us to distribute knowledge necessary for survival and to coordinate large groups. Our hominin ancestors harnessed the surfaces of mobile artifacts and cave walls as information carriers since the Paleolithic time period. Theories abound as to the meaning and function of these Paleolithic signs. However, very little is known about their basic, measurable properties. We here analyze a corpus of more than 200 mobile objects of a 43,000 to 34,000 y old Aurignacian culture — associated with the first modern humans to settle in Central Europe. These objects are adorned with several thousand geometric signs. We apply classification algorithms and statistical models to capture their quantitative properties. First, our analyses illustrate that these sign sequences are clearly distinguishable from modern day writing. Second, however, their statistical properties are comparable to sign sequences on the earliest protocuneiform tablets. Third, Paleolithic signs were systematically applied to yield higher information density on certain types of objects, e.g. ivory figurines compared to tools. These results cannot be taken to strictly prove that Aurignacian sign sequences encoded numero-ideographic information as in the case of protocuneiform. However, they prove that the first hunter-gatherers arriving in Europe already applied sign sequences of comparable complexity in a deliberate, systematic, and conventional manner — several ten thousand years before the advent of genuine writing.
The evolutionary roots of war and peace
Hugo Meijer & Richard Wrangham
Journal of Strategic Studies, forthcoming
Abstract:
When did war and peace first emerge in the human lineage? Are they deep-rooted in our evolutionary past or recent cultural inventions? This article integrates insights from evolutionary anthropology into strategic studies to address this foundational question. Using the comparative method and ethnographic analogy, it examines patterns of group interaction among humans, chimpanzees, and bonobos to determine whether such patterns are inherited from their last common ancestor or uniquely human. It argues that the inclinations for intergroup coalitionary killing and peaceful cooperation both have deep roots, and they co-evolved through a gradual, incremental trajectory over millions of years. Neither war nor peace is a unitary package that evolved at a single point in time. These complex traits originated and subsequently co-evolved through a mosaic-like pattern of development, with distinct but interacting components emerging at different moments and becoming integrated over evolutionary time. The article makes three main contributions. First, it sheds new light on when, why and how war and peace emerged in the human lineage. Second, it challenges essentialist notions of 'human nature' through a diachronic account of the evolution of human group interactions. Third, it extends the temporal scope of strategic studies beyond recorded history and state-centric analyses. By promoting interdisciplinary research — integrating biology, primatology, comparative ethology, archaeology, ethnography, social psychology, palaeoanthropology, genetics and neuroscience — it advances our understanding of the biocultural forces that shaped the evolution and persistence of war and peace.
Paleo-medicine at Gesher Benot Ya'aqov
David Jopling
Evolution and Human Behavior, March 2026
Abstract:
The 780,000 year-old archaeological site at Gesher Benot Ya'aqov (in current day Israel) contains a large assemblage of well-preserved plant remnants, among which are about 9,000 remnants that are hypothesized to be representative of the plant foods consumed by the hominins who occupied the site. This paper argues that some of the plant taxa were more likely to have been used as medicines than as foods. Six arguments support the medicinal plant hypothesis: 1. a literature search of major phytochemical and botanical databases (e.g., USDA Dr. Duke's phytochemical and ethnobotanical databases; Kew State of the world's plants) shows that a significant portion of the plant taxa in the assemblage are potentially toxic to humans, suggesting that they were more likely to have had non-dietary than dietary uses; 2. a literature search of major food nutrition databases (e.g., USDA Food Data Central) shows that a significant portion of the plant taxa have low nutritional and caloric value compared to other plant taxa and faunal material in the assemblage, also suggesting that they were more likely to have had non-dietary than dietary uses; 3. a literature search of major botanical databases shows that the proportion of medicinal to non-medicinal plant taxa in the assemblage is significantly higher than global proportions; 4. a literature search of major herbal medicine databases and reference works (e.g., USDA Dr. Duke's phytochemical and ethnobotanical databases; Native American ethnobotany database; Complete German Commission E monographs: Therapeutic guide to herbal medicines) shows that all 55 edible plant taxa in the assemblage have been used as plant medicines in traditional medicine, and most are still in use in contemporary herbal medicine; 5. a literature search of published phytochemical and pharmacological analyses of the 55 edible plant taxa shows that almost all contain medicinally active properties; and 6. the use of plant medicines would have provided significant fitness benefits to the hominins who occupied the site. Taken together, these arguments suggest that the plant assemblage at Gesher Benot Ya'aqov contains evidence of the oldest medicines used by humans.
Kava consumption and the rise of sociopolitical complexity in Oceania
Václav Hrnčíř et al.
Proceedings of the National Academy of Sciences, 3 March 2026
Abstract:
Humans have been using psychoactive substances for millennia, despite their potential negative health and social consequences. According to some scholars, our craving for mind-altering drugs is an evolutionary mistake — a hijacking of our reward system. In contrast, the "drunk hypothesis" argues that intoxication has been adaptive and essential for the rise of large-scale societies because it promotes social bonding, increases cooperation, alleviates stress, and enhances human creativity. Here, we test this hypothesis using the example of kava, a traditional Pacific beverage with a range of psychoactive effects, made from the root of Piper methysticum. Our analysis of 83 Oceanic-speaking societies shows a positive relationship between traditional kava consumption and both political complexity and social stratification. However, the results are not robust to controls for nonindependence. Moreover, we found no evidence of coevolution between kava drinking and either of the two sociopolitical traits after controlling for spatial nonindependence. Despite the cultural significance of kava in many Pacific societies, our results suggest that its consumption was unlikely to have been a major driver of sociopolitical complexity, underscoring the importance of controlling for nonindependence in cross-cultural studies.
The origins of (a culture of) cooperation
Giacomo Benati & Carmine Guerriero
Journal of Law, Economics, and Organization, forthcoming
Abstract:
We study an investment setting involving time-inconsistent elites and non-elites. The latter embrace norms that provide an intrinsic return on cooperation and may switch to a risk-sharing activity yielding a higher marginal intrinsic return. A more severe consumption risk and/or a smaller investment return increase the profitability of risk-sharing and, in turn, foster cultural accumulation. A limited investment payoff, instead, pushes the elites to enact an inclusive political process to incentivize the non-elites and the latter to reciprocate with strong norms signaling cooperation despite its limited return. These predictions are consistent with data on 44 Mesopotamian polities observed between 3050 and 1750 BCE. While the diffusion of interest-free loans of agricultural products and major irrigation infrastructures was negatively related to the harvest value, the spread of formal merchant institutions was linked to the distance to the trade circuits. Moreover, major irrigation projects were implemented where the climate was more erratic.