Cultural evolution

In the DLCE, we use interdisciplinary approaches to analyse and explain human cultural diversity across time and space. We focus our efforts on both curating and enriching cross-cultural, global databases such as D-PLACE and on using quantitative methods to explain broad-scale cultural evolution. We also study the links between cognition and culture in New Caledonian crows - a species that has convergently evolved diverse tool-making traditions.

Human cultural evolution

Testing Macro-Historical Hypotheses with Comparative Cultural Evolutionary Methods

A central aim of the Department of Linguistic and Cultural Evolution (DLCE) is to subject influential “big-history” narratives about the human past to rigorous quantitative testing using large comparative datasets and evolutionary modelling. Across several recent projects, we have combined linguistic, ecological, archaeological, and ethnographic data within a unified analytical framework to evaluate widely cited explanations for cultural diversity and societal complexity.

In Chira et al., (2024), we examined Jared Diamond’s influential “axis of orientation” hypothesis, which proposes that Eurasia’s east-west geography facilitated cultural diffusion and thereby shaped global historical inequalities. Drawing on integrated cultural, linguistic, and ecological data from more than 1,000 mainland societies, our analyses confirmed one component of Diamond’s argument: ecological barriers do indeed inhibit cultural transmission. However, contrary to the theory’s core prediction, Eurasia is not more environmentally homogeneous than other continental regions. The findings therefore demonstrate that geographic constraints matter, but not in the simple continental form often proposed in Diamond’s influential account of world history.

A second line of work investigated the claim that intoxicants played a causal role in the emergence and maintenance of complex societies. In a global sample of 186 societies, Hrnčíř et al., (2025a) found a positive association between traditional alcoholic beverages and political complexity. However, once agricultural intensity and environmental productivity were taken into account, the effect was modest. A complementary study of kava consumption in 83 Oceanic societies (Hrnčíř et al., 2025b) similarly identified correlations with political complexity and social stratification, but these relationships disappeared after controlling for spatial non-independence. Using recently developed dynamic co-evolutionary models, we further found no evidence that kava and sociopolitical institutions evolved together. Taken together, these studies show that intoxicants may accompany social complexity but are unlikely to be its primary driver.

In Chira et al., (2023), we addressed another longstanding question in human evolutionary history: the role of domesticated animals in shaping social organisation. Using newly assembled cross-cultural data on dog use and treatment in 124 societies, we demonstrated that closer human-dog relationships are associated with multifunctional roles such as hunting, guarding, and herding. Importantly, positive care and harsh treatment frequently co-occur, suggesting that dog domestication reflects a strategic balance between investment and economic utility rather than a simple moral or emotional relationship.

Across these projects, the DLCE contribution lies not only in individual empirical findings but in methodological innovation. By linking large cross-cultural databases, linguistic phylogenies, and spatially explicit evolutionary models, we move debates about human history beyond speculative narrative toward testable scientific explanation. Our results consistently show that many prominent macro-historical claims contain partial truths, but their causal structure is more complex than previously assumed. The emerging picture is that large-scale patterns of human social evolution are best explained by interacting ecological, economic, and cultural processes rather than single determining factors.

Culture and cognition in domesticated dogs

Many psychologists are now aware that claims about human psychology should not just be based on studies in WEIRD (Western, Educated, Industrialised, Rich, and Democratic) societies. Does the field of animal cognition suffer from a similar blind spot? Almost all previous work on the dog–human relationship has focused on dogs from Western, Educated, Industrialised, Rich, and Democratic (WEIRD) societies. Yet the majority of the world’s dogs live in very different cultural and ecological settings. To test whether findings from Western contexts generalise globally, we conducted a large cross-cultural field study of hunting dogs and their owners in five rural societies: Vanuatu, Mongolia, Madagascar, Peru, and Germany. We developed a standardised test battery comprising six well-established social-cognitive experiments (including pointing comprehension, perspective-taking, obedience, and responses to unsolvable problems), along with a questionnaire assessing the psychological and practical aspects of the dog–human bond. By applying the same methods across culturally diverse settings, the study provides one of the first rigorous experimental comparisons of dog–owner interactions worldwide. Despite dramatic differences in living conditions, subsistence strategies, and cultural norms, we found striking similarities in dog–human relationships across societies. While some variation was linked to hunting techniques and differences between WEIRD and non-WEIRD contexts, the overall pattern suggests that the social-cognitive foundations of the dog–human bond are remarkably consistent across cultures. The significance of this work is threefold. First, it directly addresses the “WEIRD bias” problem that affects both psychology and animal cognition research. Second, it provides rare large-scale cross-cultural experimental evidence — rather than relying solely on ethnographic databases or studies of free-ranging dogs. Third, it suggests that key aspects of the dog–human partnership, which began tens of thousands of years ago, may reflect deep evolutionary foundations that transcend local cultural variation.

Culture and cognition in new caledonian crows

Humans are unparalleled technologists. We have innovated, refined and repurposed our technological behaviours both within and across generations, producing a rich and open-ended cumulative technological culture. Yet the traits that enable cumulative technology to emerge remain poorly understood. To address this, the Crow Cognition Group (CrowCoG) adopts a comparative perspective, utilising the only phylogenetically independent species with compelling evidence of cumulative technological culture—the New Caledonian crow. This species has a rich repertoire of tool designs including barbed leaf tools of varying complexity, and the only crafted hooks besides those of humans.  Further ‘proto-tool’ behaviours include the cracking of nuts on traditional, communally-used anvils.  In the wild, CrowCoG pairs ecological and behavioural censuses to map technological behaviours and the social and asocial contexts that scaffold them; while in aviaries, we combine behavioural experiments with computational analyses to tease apart underlying (a)social learning mechanisms and cognitive abilities. Together, our research illuminates the shared and divergent drivers of complex and diversified technology in humans and crows. Our growing field and aviary datasets highlight geographic diversity in tool designs, potential generational nut-dropping styles, and cognitive mechanisms—including probabilistic inference and overhypothesis formation—long considered hallmarks of human intelligence.