Music has been called "the universal language of mankind." Although contemporary theories of music evolution often invoke various musical universals, the existence of such universals has been disputed for decades and has never been empirically demonstrated. Here we combine a music-classification scheme with statistical analyses, including phylogenetic comparative methods, to examine a well-sampled global set of 304 music recordings. Our analyses reveal no absolute universals but strong support for many statistical universals that are consistent across all nine geographic regions sampled. These universals include 18 musical features that are common individually as well as a network of 10 features that are commonly associated with one another. They span not only features related to pitch and rhythm that are often cited as putative universals but also rarely cited domains including performance style and social context. These cross-cultural structural regularities of human music may relate to roles in facilitating group coordination and cohesion, as exemplified by the universal tendency to sing, play percussion instruments, and dance to simple, repetitive music in groups. Our findings highlight the need for scientists studying music evolution to expand the range of musical cultures and musical features under consideration. The statistical universals we identified represent important candidates for future investigation.ethnomusicology | cross-cultural universals | group coordination | evolution | cultural phylogenetics

Why do humans make music? Theories of the evolution of musicality have focused mainly on the value of music for specific adaptive contexts such as mate selection, parental care, coalition signaling, and group cohesion. Synthesizing and extending previous proposals, we argue that social bonding is an overarching function that unifies all of these theories, and that musicality enabled social bonding at larger scales than grooming and other bonding mechanisms available in ancestral primate societies. We combine cross-disciplinary evidence from archaeology, anthropology, biology, musicology, psychology, and neuroscience into a unified framework that accounts for the biological and cultural evolution of music. We argue that the evolution of musicality involves gene-culture coevolution, through which proto-musical behaviors that initially arose and spread as cultural inventions had feedback effects on biological evolution due to their impact on social bonding. We emphasize the deep links between production, perception, prediction, and social reward arising from repetition, synchronization, and harmonization of rhythms and pitches, and summarize empirical evidence for these links at the levels of brain networks, physiological mechanisms, and behaviors across cultures and across species. Finally, we address potential criticisms and make testable predictions for future research, including neurobiological bases of musicality and relationships between human music, language, animal song, and other domains. The music and social bonding (MSB) hypothesis provides the most comprehensive theory to date of the biological and cultural evolution of music.

SignificanceDo human societies from around the world exhibit similarities in the way that they are structured and show commonalities in the ways that they have evolved? To address these long-standing questions, we constructed a database of historical and archaeological information from 30 regions around the world over the last 10,000 years. Our analyses revealed that characteristics, such as social scale, economy, features of governance, and information systems, show strong evolutionary relationships with each other and that complexity of a society across different world regions can be meaningfully measured using a single principal component of variation. Our findings highlight the power of the sciences and humanities working together to rigorously test hypotheses about general rules that may have shaped human history.

The origins of both religion and complex societies represent evolutionary puzzles [1][2][3][4][5][6][7][8] . The moralizing gods hypothesis offers a solution to both puzzles by proposing that belief in morally concerned supernatural agents culturally evolved to facilitate cooperation among strangers in large-scale societies [9][10][11][12][13] . While previous research has suggested an association between presence of moralizing gods and social complexity 3,6,7,[9][10][11][12][13][14][15][16][17][18] , the relationship between the two is disputed 9,10,13,19,20,23,24 , and attempts to establish causality have been hampered by limitations in the availability of detailed global longitudinal data. To overcome these limitations, we systematically coded records for 414 societies spanning the last 10,000 years from 30 regions around the world, based on 51 measures of social complexity and four measures of supernatural enforcement of morality. Our analyses confirm the association between moralizing gods and social complexity but reveal that moralizing gods follow, rather than precede, large increases in social complexity. Contrary to previous predictions 9,12,16,18 , powerful moralizing "big gods", and prosocial supernatural punishment more generally, tend to appear only after the emergence of "megasocieties" with populations of greater than around a million. Although moralizing gods are not a prerequisite for the evolution of social complexity, they may help to sustain and expand complex multiethnic empires after they have become established. In contrast, rituals facilitating the standardization of religious traditions across large populations 25,26 generally precede the appearance of moralizing gods. This suggests that ritual practices were more important than the particular content of religious belief to the initial rise of social complexity.Supernatural agents that punish direct affronts to themselves (e.g. failure to perform sacrifices or observe taboos) are commonly represented in global history, but rarely are such deities believed to punish moral violations in interactions between humans 2 . Recent