**Author(s):** Hong, Ze; Chen, Yuqi Introduction: The study of rhetoric and argumentation has a long history in the western intellectual tradition, yet relatively less attention has been paid to its relationship between other cognitive themes such as reasoning and epistemology, as well as cultural and historical variation in persuasion practices in non-western contexts. Methods: We used keyword searches to identify persuasion episodes (763 total) in the official dynastic histories in China to systematically examine various rhetorical/argumentation strategies (e.g., argument by analogy, argument by authority, etc.) used in the past two millennia. Results: We found that early dynasties tend to have higher recorded persuasion success with the notable exception of the Ming dynasty, and there appears to be a temporal decline in the frequency in rhetorical strategies associated with persuasion failures (e.g., analogy and the use of auspicious/inauspicious signs). Conclusion: We found some support for adaptive cultural change in the type of arguments that people use. This study highlights the possibility of using rhetoric/argumentation as a tool to investigate reasoning and epistemology, as well as testing cultural evolutionary hypothesis using historical data.

Persuading the Emperors: A Quantitative Historical Analysis of Political Rhetoric in Traditional China

**Author(s):** Sheard, C; Bowern, C; Jordan, F M Introduction: Human kinship systems, or how different cultural groups use language to classify family members, show remarkable global diversity, but they also seem to be constrained by social and cognitive limits. It is common within anthropology, for example, for kinship systems to be categorised into a mere six typologies, based on a few axes of variation in cousin terms. Despite the importance of kinship in structuring human society, however, there has been little work examining the cross-cultural drivers of, and constraints on, this diversity, and most of this scholarship has been limited to a handful of well-documented language families. Materials and Methods: Here, we present a survey of kinship systems in 71 Pama-Nyungan languages, representing all major branches of the largest Australian language family. We first describe the macroevolutionary dynamics of Pama-Nyungan kinship and test for evidence of stable kinship typologies. We then test hypotheses related to how social practice and spatial variables shape kinship systems. Results: We find only weak support for any clustering of languages by kinship system or for specific holes within the observed volume of kinship space, instead demonstrating that these ethnolinguistic groups’ kinship systems have evolved steadily over the past ~ 6,000 years. We find that community marriage norms, but not post-marital residency, correlate with kinship system. Furthermore, though we find evidence of spatial autocorrelation in the data above and beyond the effect of shared phylogenetic history, we find that spatial similarity in kinship systems is better explained by a correlation between kinship and the physical environment. Conclusions: By applying modern phylogenetic comparative methods to the study of language-culture coevolution, we thus demonstrate the importance of moving beyond traditional typological comparisons in the study of kinship, as well as caution against assuming the universal applicability of cultural evolution trends across all geographic and linguistic contexts.

Social practice and physical environment shape Pama-Nyungan kinship macroevolution, but not into stable typologies

Introduction: Santa Claus is a morally concerned, omniscient, interventionist supernatural agent. Belief in a ‘real’ Santa emerges in early childhood, is highly contingent upon adult endorsement, and typically ceases in the 7th year. Studying children may yield insights into the development and evolution of religious cognition. We expect that belief and exposure to cultural rituals will predict children's moral behavior during the Xmas period. Methods: We collected longitudinal data from parents (on Prolific) regarding their child’s belief in Santa, cultural practices and symbols, Santa’s moral concerns, and child prosocial behavior in the preceding week both before the Xmas period (T1: 25 November), and for the apex of the Xmas festival (T2: 26 December; N = 97). Results: Preliminary results suggest that disobedience/aggression did not change over the Xmas period, but that prompted prosociality increased, and unprompted prosociality decreased. The change was not predicted by belief in Santa, ritual salience, Xmas-relevant CREDs, or age. Discussion: Our real-world data among children have implications for the generalizability, learnability, and evolvability of the ‘Big Gods’ hypothesis.

We’ve made a list and we’re checking it twice: A two-wave longitudinal study of children’s moral behavior during Christmas

**Author(s):** Matthews, Luke J.; Khan, Omair Introduction: Shared understandings of current events are crucial to any functional modern society but common understandings even about factual elements of “what happened” during an event are frequently and hotly contested. Methods: We applied cultural consensus analysis (CCA) and cluster analysis to hundreds of thematically coded journalistic articles from a 2019 air skirmish between India and Pakistan. We applied these methods longitudinally to test alternative hypotheses that either narrative consensus about factual elements increased or decreased over time. Results: Consensus about factual elements of the 2019 air skirmish decreased over a two month period as the narrative diverged into two increasingly thematically distinct clusters. Conclusions: At least regarding the 2019 India-Pakistan air skirmish, journalistic articles decreased in consensus about facts over time. If these results generalize, then media companies might improve shared understandings by repeating articles from closer in time to actual events, as these articles show greater potential for narratives reflecting factual consensus.

Rapid cultural evolution of current event narratives

**Author(s):** Kasser, S. M.; Blanco-Portillo, J.; Fortunato, L.; Laland, K. N. Objective: Gene-culture coevolution (GCC) theory routinely predicts interactions between cultural and genetic variation that should emerge through empirical analyses, yet evidence for such associations remains sparse. By adapting tools that quantify ecological drivers of population genetic structure ("landscape genomics"), we explore potential cultural drivers of human genetic variation across Oceania to evaluate the extent of GCC.

Methods: We will introduce landscape genomics as a method of quantifying gene-culture coevolution. In a short test case, we use high-density SNP data from Oceanian individuals across 17 island populations from the OGVP (a collaboration between Oxford and Stanford). We then analyse these frequencies using GESTE, a Bayesian procedure to estimate the influence of environmental factors on population genetic structure. For the present analysis, cultural and ecological factors relating to subsistence, kinship practices and island ecology are drawn from relevant cross-cultural datasets.

Results: We will present results on associations between cultural factors and genetic structure.

Discussion: We will discuss the results in the context of recent work on how culture may shape genetic variation beyond classic examples of GCC, and whether landscape genomics represents a useful analogy for quantifying GCC.

Unravelling gene-culture coevolution in the Pacific

INTRODUCTION: Phylogenetic methods are used for the reconstruction of historical relationships between cultural lineages. These methods, designed for biological evolution, assume traits can only be transferred via inheritance. Little work has been done to determine how the introduction of horizontal transmission, potentially ubiquitous in cultural evolution, affects their accuracy. OBJECTIVE: In this study we tested the robustness of phylogenetic methods when applied to a demographic process with horizontal transmission of traits between groups. APPROACH: We generated synthetic population histories represented as phylogenetic trees. We then simulated variant data on the trees, sampled the terminal nodes and used standard phylogenetic reconstruction methods to construct best fitting trees from the leaf data. We assessed the accuracy of the phylogenetic reconstruction as the distance between the best fitting tree and the ‘true’ tree representation of the demographic history. FINDINGS: Phylogenetic methods are reliable only when the borrowing is constrained to groups with a recent common ancestor. In addition, borrowing can be constrained by either shared ancestry or spatial proximity, leading to significantly divergent inferred trees. CONCLUSION: Preliminary results suggest that the introduction of demographic complexity, including extinction of groups and horizontal transmission events, significantly decreases the accuracy of phylogenetic inference.

Can cultural phylogenies accurately capture spatially explicit demographic scenarios?

**Author(s):** Lee, H; Schönwiesner, M; Jacoby, N; Park, M

Background: Music is a rich cultural product that is practiced across all known cultures and throughout history, making it an attractive medium to study the transmission and evolution of culture. However, previous research on empirical analysis of music predominantly relied on Western songs, limiting our understanding to WEIRD countries. 
 Method: We introduce a novel dataset called GlobalPOP, which gathers music records from 55 countries since the 1950s by crawling web pages and manually transcribing from books and magazines. The dataset contains over 4 million entries and 254,234 songs with acoustic information, lyrics, and other meta-data gathered from various sources. 
 Results: Using this rich dataset, we provide a quantitative picture on how the general preference of music has converged and diverged across the globe over the last seven decades. Our preliminary findings indicate that most acoustic features reveal a country-specific or regional trend (e.g., danceability, tempo, energy) that can be grouped by the spoken-language and geographical proximity, whereas only a handful of low-level features can be considered as a global trend (e.g., song duration, loudness). 
 Conclusion: We present the first empirical work on the evolution of cross-cultural music preferences by making use of the most comprehensive longitudinal music chart data which will become open-access.

Studying the evolution of pop music across 55 countries since the 1950s

**Author(s):** Micheletti, AJC & Mace, R Introduction: Most major world religions require at least some of their practitioners to commit to lifelong celibacy. A recent evolutionary model has suggested that inducing a son to become a monk can be adaptive if it increases his brothers’ reproductive success and a sociodemographic study has shown that this is the case in a Tibetan Buddhist population. However, female celibates are present in other religions and parts of the world, and it remains unclear what might drive differences in their frequency relative to male celibates. Approach: Here, we develop an evolutionary, inclusive fitness model of the coevolution of male and female lifelong celibacy. Results: We find that the frequency of monks and nuns can be influenced by how parental resources are shared among offspring and how siblings compete for them. More monks than nuns are favoured when competition is more intense between brothers than sisters, that is when resources are more important for male than female reproductive success (bride price societies). The opposite is true when competition is more intense between sisters (dowry societies). We also find a role for the extent to which brothers and sisters compete for the same pool of resources, which is influenced by cultural inheritance rules and whether wealth is mainly immovable (land) or movable (money, cattle). Moreover, the sex that disperses less is favoured to have more celibates. Discussion: These results can help us explain observed differences in the frequency of monks and nuns in societies with different marriage systems, inheritance rules and post-marital residence rules.

Sibling competition and dispersal drive sex differences in religious celibacy

**Author(s):** Pichkar, Y; Creanza, N Introduction: Human culture is both a bearer of history and an active force in it. The history of cultures can resemble that of our genes, but the impact of cultural identity on long-term patterns of human interaction has not been extensively researched. We leverage increasingly available genetic and cultural databases to explore how culture has shaped populations in Great Britain. Approach: We used the Survey of English Dialects to produce a map of linguistic variation, a type of cultural variation. From the genetic data collected for the People of the British Isles project, we reconstruct previously found genetic clustering (Leslie et al. 2015). Using the genetic variation within and between clusters, we measured whether genetic variation coincides with dialect borders. Results: We find that these patterns are strongest in areas with larger cultural divides–near Scotland and Wales–but correlations also exist closer to the center of England. Conclusions: These patterns suggest that cultural boundaries have shaped people’s preferences for movement and marriage over the last millennium, and that cultural identity may contribute to establishing genetic differentiation in a region.

Cultural reinforcement of genetic boundaries in England

 I propose a mathematical model of cultural evolution to explain why false theories and meaning systems or maladaptive beliefs may spread and become fixed in a population while assuming that their diffusion rates are lower than their true counterparts. By combining ideas from judgment aggregation and the Condorcet Jury theorem with cultural evolution dynamics, I introduce a new epistemic stage in the cultural evolution process where culturally transmitted theories not only spread “horizontally” (across individuals in the same generation) and “vertically” (from one generation to the next), but also inside individual brains (“personal reflection process”). This occurs when a brain adopts a maladaptive theory (not received from outside) by means of internal inference from other false premise/idea that was indeed received culturally. In this context, false theories may favor the assumption of other false theories after the individuals have been exposed to true information about their logical connection, and increase their presence in the population within the normal and adaptive logical working of our brains. Using a simple stylized model and subsequent simulations I identify the parametric conditions in which false theories become universally accepted, so that the model could be tested empirically.

The evolution of false theories

 Two important hypotheses compete to explain the human adaptation. The cognitive niche hypothesis proposes that gene-based evolution in the Pleistocene favored the evolution of information rich encapsulated cognitive modules adapted to the regularities of the Pleistocene environment. The cultural niche hypothesis argues that the hallmark of Pleistocene environments was extreme variability on millennial and submillennial time scales and that culture is an adaptation this. These hypotheses have very different implications for how the human mind/brain would work. Some neurobiologists for some time have argued that the cerebral cortex has to operate as an organ of phenotypic flexibility and that genes specify, in any detail, only the ancient emotional and vegetative parts of the brain. Recent neurobiological advances support this latter picture of cortical function. The ancient but rather generalized appetites and emotions provide the selective forces on the developmental time scale that also act as forces on the cultural evolutionary time scale. These advances tend to support the cultural niche hypothesis and are not consistent with the cognitive niche alternative.

The cognitive niche versus cultural niche hypotheses: The neurobiological evidence

**Author(s):** Anglada-Tort, M; Harrison, P M C; Jacoby, N Introduction: 
In most human cultures, music and speech are sustained through oral transmission. How do cognitive and motor constraints in this process shape the evolution of music? Music corpus studies have been particularly useful to characterize common and diverse features observed in human songs across cultures (Mehr et al., 2019; Savage, 2015), yet these studies fail to quantify how and why these features emerge. Alternatively, iterated learning experiments provide a powerful quantitative tool for studying how transmission biases shape the evolution of language and music. However, such experiments have traditionally been conducted in nonautomated laboratory settings, making data collection costly while limiting the ability to explore the full space of evolutionary possibilities. 
 Methods: 
Here we present the first large-scale cultural evolution study on human song, quantifying the evolution of thousands of melodies transmitted orally across participants. Our method is applicable to individuals from any cultural background and works efficiently on computers available to most participants online. We perform many variations of this paradigm, including varying the total number of notes per melody (3-12 notes), adding memory load and motor constraints in the singing task, or naturalistic singing.
 Results: 
We show that cognitive and motor constraints in oral transmission play a profound role in the emergence of melodic structure. Specifically, initially random tones develop into more structured systems that increasingly reuse and combine fewer elements, making melodies easier to learn and transmit over time. Importantly, melodic features that emerged artificially from our experiments are largely consistent with melodic universals observed cross-culturally (e.g., small intervals, discrete scales, and tonal structures). Parallel to this, we find that evolving melodies tend to align with melodic pleasantness (estimated by a separate rating experiment with Western listeners) and musical exposure (estimated by a large corpus of popular Western melodies). 
Discussion: 
Taken together, our results provide the first quantitative characterization of the rich collection of biases that oral transmission imposes on music evolution, giving us a new understanding of the emergence of musical universals and the resulting vast structural diversity of human song.

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Persuading the Emperors: A Quantitative Historical Analysis of Political Rhetoric in Traditional China

Social practice and physical environment shape Pama-Nyungan kinship macroevolution, but not into stable typologies

We’ve made a list and we’re checking it twice: A two-wave longitudinal study of children’s moral behavior during Christmas

Rapid cultural evolution of current event narratives

Unravelling gene-culture coevolution in the Pacific

Can cultural phylogenies accurately capture spatially explicit demographic scenarios?

Studying the evolution of pop music across 55 countries since the 1950s

Sibling competition and dispersal drive sex differences in religious celibacy

Cultural reinforcement of genetic boundaries in England

The evolution of false theories

The cognitive niche versus cultural niche hypotheses: The neurobiological evidence

Large-scale online iterated singing experiments reveal oral transmission effects in the evolution of human song

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