Global musical diversity is largely independent of linguistic and genetic histories.

Music is a universal yet diverse cultural trait transmitted between generations. The extent to which global musical diversity traces cultural and demographic history, however, is unresolved. Using a global musical dataset of 5242 songs from 719 societies, we identify five axes of musical diversity and show that music contains geographical and historical structures analogous to linguistic and genetic diversity. After creating a matched dataset of musical, genetic, and linguistic data spanning 121 societies containing 981 songs, 1296 individual genetic profiles, and 121 languages, we show that global musical similarities are only weakly and inconsistently related to linguistic or genetic histories, with some regional exceptions such as within Southeast Asia and sub-Saharan Africa. Our results suggest that global musical traditions are largely distinct from some non-musical aspects of human history.

The Exceptions and the Rules in Global Musical Diversity.

Global music diversity is a popular topic for both scientific and humanities researchers, but often for different reasons. Scientific research typically focuses on the generalities through measurement and statistics, while humanists typically emphasize exceptions using qualitative approaches. But these two approaches need not be mutually exclusive. Using a quantitative approach to identify musical outliers and a qualitative discussion of the most unusual songs, we can combine scientific and humanities approaches to unite knowledge on musical diversity. Objectively defining unusual music is a delicate task, having historically been subject to Eurocentric approaches. Using the Global Jukebox, a dataset containing almost 6,000 songs from over 1,000 societies coded on 37 "Cantometric" variables of musical style, we designate the unusualness of a song as the frequency of its coded variables relative to their regional frequency. Using quantitative metrics to identify outliers in musical diversity, we present a qualitative discussion of some of the most unusual individual songs (from a Panpipe ensemble from Kursk, Russia), and a comparison of unusual repertoires from Malay, Kel Aïr, and Moroccan Berber musical cultures. We also ask whether unusual music is the result of unusual social organisation or isolation from other groups. There is weak evidence that the unusualness of music is predicted by kinship organisation and cultural isolation, but these predictors are heavily outweighed by the finding that unusual songs are best predicted by knowing the society they come from - evidence that quantitatively supports the existence of musical style.

Convergent evolution in a large cross-cultural database of musical scales.

Scales, sets of discrete pitches that form the basis of melodies, are thought to be one of the most universal hallmarks of music. But we know relatively little about cross-cultural diversity of scales or how they evolved. To remedy this, we assemble a cross-cultural database (Database of Musical Scales: DaMuSc) of scale data, collected over the past century by various ethnomusicologists. Statistical analyses of the data highlight that certain intervals (e.g., the octave, fifth, second) are used frequently across cultures. Despite some diversity among scales, it is the similarities across societies which are most striking: step intervals are restricted to 100-400 cents; most scales are found close to equidistant 5- and 7-note scales. We discuss potential mechanisms of variation and selection in the evolution of scales, and how the assembled data may be used to examine the root causes of convergent evolution.

Group singing is globally dominant and associated with social context.

Music is an interactive technology associated with religious and communal activities and was suggested to have evolved as a participatory activity supporting social bonding. In post-industrial societies, however, music's communal role was eclipsed by its relatively passive consumption by audiences disconnected from performers. It was suggested that as societies became larger and more differentiated, music became less participatory and more focused on solo singing. Here, we consider the prevalence of group singing and its relationship to social organization through the analysis of two global song corpora: 5776 coded audio recordings from 1024 societies, and 4709 coded ethnographic texts from 60 societies. In both corpora, we find that group singing is more common than solo singing, and that it is more likely in some social contexts (e.g. religious rituals, dance) than in others (e.g. healing, infant care). In contrast, relationships between group singing and social structure (community size or social differentiation) were not consistent within or between corpora. While we cannot exclude the possibility of sampling bias leading to systematic under-sampling of solo singing, our results from two large global corpora of different data types provide support for the interactive nature of music and its complex relationship with sociality.

Societies of strangers do not speak less complex languages.

Many recent proposals claim that languages adapt to their environments. The linguistic niche hypothesis claims that languages with numerous native speakers and substantial proportions of nonnative speakers (societies of strangers) tend to lose grammatical distinctions. In contrast, languages in small, isolated communities should maintain or expand their grammatical markers. Here, we test these claims using a global dataset of grammatical structures, Grambank. We model the impact of the number of native speakers, the proportion of nonnative speakers, the number of linguistic neighbors, and the status of a language on grammatical complexity while controlling for spatial and phylogenetic autocorrelation. We deconstruct "grammatical complexity" into two separate dimensions: how much morphology a language has ("fusion") and the amount of information obligatorily encoded in the grammar ("informativity"). We find several instances of weak positive associations but no inverse correlations between grammatical complexity and sociodemographic factors. Our findings cast doubt on the widespread claim that grammatical complexity is shaped by the sociolinguistic environment.

Kinbank: A global database of kinship terminology.

For a single species, human kinship organization is both remarkably diverse and strikingly organized. Kinship terminology is the structured vocabulary used to classify, refer to, and address relatives and family. Diversity in kinship terminology has been analyzed by anthropologists for over 150 years, although recurrent patterning across cultures remains incompletely explained. Despite the wealth of kinship data in the anthropological record, comparative studies of kinship terminology are hindered by data accessibility. Here we present Kinbank, a new database of 210,903 kinterms from a global sample of 1,229 spoken languages. Using open-access and transparent data provenance, Kinbank offers an extensible resource for kinship terminology, enabling researchers to explore the rich diversity of human family organization and to test longstanding hypotheses about the origins and drivers of recurrent patterns. We illustrate our contribution with two examples. We demonstrate strong gender bias in the phonological structure of parent terms across 1,022 languages, and we show that there is no evidence for a coevolutionary relationship between cross-cousin marriage and bifurcate-merging terminology in Bantu languages. Analysing kinship data is notoriously challenging; Kinbank aims to eliminate data accessibility issues from that challenge and provide a platform to build an interdisciplinary understanding of kinship.

Grambank reveals the importance of genealogical constraints on linguistic diversity and highlights the impact of language loss.

While global patterns of human genetic diversity are increasingly well characterized, the diversity of human languages remains less systematically described. Here, we outline the Grambank database. With over 400,000 data points and 2400 languages, Grambank is the largest comparative grammatical database available. The comprehensiveness of Grambank allows us to quantify the relative effects of genealogical inheritance and geographic proximity on the structural diversity of the world's languages, evaluate constraints on linguistic diversity, and identify the world's most unusual languages. An analysis of the consequences of language loss reveals that the reduction in diversity will be strikingly uneven across the major linguistic regions of the world. Without sustained efforts to document and revitalize endangered languages, our linguistic window into human history, cognition, and culture will be seriously fragmented.

Sequence alignment of folk song melodies reveals cross-cultural regularities of musical evolution.

Culture evolves,1-5 but the existence of cross-culturally general regularities of cultural evolution is debated.6-8 As a diverse but universal cultural phenomenon, music provides a novel domain to test for the existence of such regularities.9-12 Folk song melodies can be thought of as culturally transmitted sequences of notes that change over time under the influence of cognitive and acoustic/physical constraints.9-15 Modeling melodies as evolving sequences constructed from an "alphabet" of 12 scale degrees16 allows us to quantitatively test for the presence of cross-cultural regularities using a sample of 10,062 melodies from musically divergent Japanese and English (British/American) folk song traditions.17,18 Our analysis identifies 328 pairs of highly related melodies, finding that note changes are more likely when they have smaller impacts on a song's melody. Specifically, (1) notes with stronger rhythmic functions are less likely to change, and (2) note substitutions are most likely between neighboring notes. We also find that note insertions/deletions ("indels") are more common than note substitutions, unlike genetic evolution where the reverse is true. Our results are consistent across English and Japanese samples despite major differences in their scales and tonal systems. These findings demonstrate that even a creative art form such as music is subject to evolutionary constraints analogous to those governing the evolution of genes, languages, and other domains of culture.

The Global Jukebox: A public database of performing arts and culture.

Standardized cross-cultural databases of the arts are critical to a balanced scientific understanding of the performing arts, and their role in other domains of human society. This paper introduces the Global Jukebox as a resource for comparative and cross-cultural study of the performing arts and culture. The Global Jukebox adds an extensive and detailed global database of the performing arts that enlarges our understanding of human cultural diversity. Initially prototyped by Alan Lomax in the 1980s, its core is the Cantometrics dataset, encompassing standardized codings on 37 aspects of musical style for 5,776 traditional songs from 1,026 societies. The Cantometrics dataset has been cleaned and checked for reliability and accuracy, and includes a full coding guide with audio training examples (https://theglobaljukebox.org/?songsofearth). Also being released are seven additional datasets coding and describing instrumentation, conversation, popular music, vowel and consonant placement, breath management, social factors, and societies. For the first time, all digitized Global Jukebox data are being made available in open-access, downloadable format (https://github.com/theglobaljukebox), linked with streaming audio recordings (theglobaljukebox.org) to the maximum extent allowed while respecting copyright and the wishes of culture-bearers. The data are cross-indexed with the Database of Peoples, Languages, and Cultures (D-PLACE) to allow researchers to test hypotheses about worldwide coevolution of aesthetic patterns and traditions. As an example, we analyze the global relationship between song style and societal complexity, showing that they are robustly related, in contrast to previous critiques claiming that these proposed relationships were an artifact of autocorrelation (though causal mechanisms remain unresolved).

No universals in the cultural evolution of kinship terminology.

Kinship terminologies are the semantic systems of language that express kinship relations between individuals: in English, 'aunt' denotes a parent's sister. Theoretical models of kinship terminology diversity reduce over 10 billion possible organisations to six key types, each of which are hypothesised to be aligned with particular cultural norms of descent, marriage or residence patterns (Murdock, 1949). Often, terminological type is used to infer social patterns in past societies based on these putative relationships between kinship terminologies and social structure, and these associations are staples of 'Anthropology 101'. However, these relationships have not been scrutinised using modern comparative methods. Here we show that kinship terminologies vertically track language phylogeny in Austronesian, Bantu, and Uto-Aztecan, three languages families of different time-depths and environments. We find no unidirectional or universal models of evolution in kinship terminology. Of 18 existing anthropological coevolutionary theories regarding kinship terminology and cultural practices across 176 societies, we find only patchy support, and no evidence for putative universal drivers of evolution in kinship terminologies.

Social Practice and Shared History, Not Social Scale, Structure Cross-Cultural Complexity in Kinship Systems.

Human populations display remarkable diversity in language and culture, but the variation is not without limit. At the population level, variation between societies may be structured by a range of macro-evolutionary factors, including ecological and environmental resources, shared ancestry, spatial proximity, and covarying social practices. Kinship terminology systems are varying linguistic paradigms that denote familial social relationships of kin and non-kin. Systems vary by the kinds of salient distinctions that are made (e.g., age, gender, generation) and the extent to which different kinds of kin are called by the same term. Here, we explore two kinds of explanations for an observed typology of kin terms for cousins. The first one derives the typology from a learning bottleneck linked to population size. This would lead to a correlation between community size and the type of kinship system. The second one derives it from a set of social practices, particularly marriage and transfer of resources that might shape kinship systems. Using a global ethnographic database of over a thousand societies, we show that marriage rules and shared linguistic affiliation have a significant influence on the type of kinship system found in a society. This remains true if we control for the effect of spatial proximity and cultural ancestry. By combining cognitive and historic approaches to this aspect of kinship, we suggest broader implications for the study of human social cognition in general.

Text analysis shows conceptual overlap as well as domain-specific differences in Christian and secular worldviews.

Theories differ over whether religious and secular worldviews are in competition or represent overlapping and compatible frameworks. Here we test these theories by examining homogeneity and overlap in Christian and non-religious people's explanations of the world. Christian and non-religious participants produced free text explanations of 54 natural and supernatural phenomena. Using a new text analytic approach, we quantitatively measure the similarity between 7613 participant generated explanations. We find that the relative homogeneity of Christian and non-religious people's explanations vary depending on the kind of phenomena being explained. Non-religious people provided more similar explanations for natural than supernatural phenomena, whereas Christian explanations were relatively similar across both natural and supernatural phenomena. This challenges the idea that religious systems standardize and restrict people's worldviews in general, and instead suggest this effect is domain specific. We also find Christian and non-religious participants used largely overlapping concepts to explain natural and supernatural phenomena. This suggests that religious systems supplement rather than compete with secular based worldviews, and demonstrates how text analytics can help understand the structure of group differences.

Usage frequency and lexical class determine the evolution of kinship terms in Indo-European.

Languages do not replace their vocabularies at an even rate: words endure longer if they are used more frequently. This effect, which has parallels in evolutionary biology, has been demonstrated for the core vocabulary, a set of common, unrelated meanings. The extent to which it replicates in closed lexical classes remains to be seen, and may indicate how general this effect is in language change. Here, we use phylogenetic comparative methods to investigate the history of 10 kinship categories, a type of closed lexical class of content words, across 47 Indo-European languages. We find that their rate of replacement is correlated with their usage frequency, and this relationship is stronger than in the case of the core vocabulary, even though the envelope of variation is comparable across the two cases. We also find that the residual variation in the rate of replacement of kinship terms is related to genealogical distance of referent to kin. We argue that this relationship is the result of social changes and corresponding shifts in the entire semantic class of kinship terms, shifts typically not present in the core vocabulary. Thus, an understanding of the scope and limits of social change is needed to understand changes in kinship systems, and broader context is necessary to model cultural evolution in particular and the process of system change in general.

Cultural and Environmental Predictors of Pre-European Deforestation on Pacific Islands.

The varied islands of the Pacific provide an ideal natural experiment for studying the factors shaping human impact on the environment. Previous research into pre-European deforestation across the Pacific indicated a major effect of environment but did not account for cultural variation or control for dependencies in the data due to shared cultural ancestry and geographic proximity. The relative importance of environment and culture on Pacific deforestation and forest replacement and the extent to which environmental impact is constrained by cultural ancestry therefore remain unexplored. Here we use comparative phylogenetic methods to model the effect of nine ecological and two cultural variables on pre-European Pacific forest outcomes at 80 locations across 67 islands. We show that some but not all ecological features remain important predictors of forest outcomes after accounting for cultural covariates and non-independence in the data. Controlling for ecology, cultural variation in agricultural intensification predicts deforestation and forest replacement, and there is some evidence that land tenure norms predict forest replacement. These findings indicate that, alongside ecology, cultural factors also predict pre-European Pacific forest outcomes. Although forest outcomes covary with cultural ancestry, this effect disappears after controlling for geographic proximity and ecology. This suggests that forest outcomes were not tightly constrained by colonists' cultural ancestry, but instead reflect a combination of ecological constraints and the short-term responses of each culture in the face of those constraints.

Shared Cultural History as a Predictor of Political and Economic Changes among Nation States.

Political and economic risks arise from social phenomena that spread within and across countries. Regime changes, protest movements, and stock market and default shocks can have ramifications across the globe. Quantitative models have made great strides at predicting these events in recent decades but incorporate few explicitly measured cultural variables. However, in recent years cultural evolutionary theory has emerged as a major paradigm to understand the inheritance and diffusion of human cultural variation. Here, we combine these two strands of research by proposing that measures of socio-linguistic affiliation derived from language phylogenies track variation in cultural norms that influence how political and economic changes diffuse across the globe. First, we show that changes over time in a country's democratic or autocratic character correlate with simultaneous changes among their socio-linguistic affiliations more than with changes of spatially proximate countries. Second, we find that models of changes in sovereign default status favor including socio-linguistic affiliations in addition to spatial data. These findings suggest that better measurement of cultural networks could be profoundly useful to policy makers who wish to diversify commercial, social, and other forms of investment across political and economic risks on an international scale.