This article explores the possible relationship between the cultural evolution of language, music, and genetic variation beyond the level of language families. Due to their linguistic diversity, the authors use a sample of 14 Northeast Asian societies with matching information on their music, genetics, and linguistic patterns. The variables measuring language are lexicon, phonology, and grammar. Then, the authors compare each variable's relationship to music and genetic variation. The results only show a significant correlation between grammar and genetic variation.

By analyzing patterns of between- and within-population musical variability among 16 Austronesian-speaking aboriginal groups, the researchers hope to evaluate degree of similarity to structures of human genetic diversity. As in the genetic domain, within-population variance is found to be much higher than between-population variance, leading the researchers to suggest that patterns of musical distance and divergence may serve as an indicator of cultural evolution.

While not mechanically related, the transmission of genes and the transmission of languages are both mediated by culture. For example, in societies where marriage outside the language group is common, matrilocal residence practices may result in the preferential conservation of the mother’s language(s), as well as the development of distinct mtDNA haplogroups throughout a region. In this study, the authors use single nucleotide polymorphism (SNP) data from 130 culturally distinct populations to assess the correlation between genetic distance and linguistic distance, while controlling for various cultural and geographic factors (in other words: when populations are more genetically dissimilar, do they also tend to be further apart linguistically?). Results suggest that while the often-referenced idea of sex-based transmission of language is not universally predictable, linguistic distance almost always tends to correlate positively to both spatial and mitochondrial genetic variation.

Genetic, linguistic, and geographic data can be used to explain the distribution of cultural units ("semes") and to understand the evolutionary mechanisms of culture. Three broad models of cultural transmission attempt to explain why cultures share semes: (1) Cultural diffusion, emphasizing horizontal transmission. (2) Local adaptation, where trail-and-error learning leads to the independent adoption of semes by different peoples living in similar environments. (3) Demic diffusion, which emphasizes vertical and frequency-dependent transmission. Authors test the explanatory power of each model using cultural, genetic, linguistic and geographic data from 36 African cultures.

The authors examine musical diversity in India using cantometric data from 32 Indian societies with the goal of better understanding how music varies between and within cultures. They find very minor musical differences between language families, greater diversity between societies but within language families, and the most variation within societies.

This chapter explores the relationship between cultural complexity and song. Several measures of cultural complexity are correlated with different aspects of singing. All hypotheses are supported.

The researcher looks for empirical evidence of natural selection as an explanation for worldwide variation in novelty-seeking behavior. Examining the relationship between variability in frequency of the DRD4 exon III 7-repeat allele variant (a variant theorized to stifle dopamine reception and thus encourage compensatory novelty-seeking behavior) and migratory distance from prehistoric humans' origin point in East Africa yields a positive correlation. After controlling for various biogeographic indicators, the researcher theorizes that presence of the DRD4 exon III 7-repeat variant provided an exploratory urge and evolutionary advantage to hunter-gatherers and pastoralists who migrated into unfamiliar environments.

Dopamine receptor D4 (DRD4) exhibits the largest number of polymorphisms of any dopamine receptor yet identified, and variation in DRD4 has been linked to variation in traits such as novelty-seeking and attention deficit/hyperactivity disorder. DRD4 also exhibits large variation between populations. Here, the authors test the hypothesis that natural selection acting on DRD4 may account for variation in between-population migratory patterns, using genetic and historical data from 39 populations.

In asking whether or not there are meaningful universals in music, researchers compiled two catalogs – the Natural History of Song (NHS) Ethnography which contains ethnographic descriptions of song performances collected from eHRAF World Cultures, and the NHS Discography, which contains field recordings of performances of dance, healing, love, and lullaby. Using these two corpora, the study tests a variety of hypotheses about the universality and variability of both music behavior and music form. Specifically, whether there are meaningful universals in meaning and sound. The catalog of published sound recordings was analyzed by machine summaries, listener ratings, and manual transcriptions, which revealed that there were identifiable features of songs which could then predict their primary function cross-culturally. The results as a whole revealed that the existence of music is a cultural universal, and that the variation within music can be characterized by three factors assessing the formality, arousal, and religiosity of the song events. They also found that musical behavior varies more within societies than between them.

This study explores the prevalence of group singing and its relationship with changes in social organization's participatory dynamics, precisely community size and social differentiation. The authors use two samples: 1) 5776 audio recordings from 1024 societies and 2) 4709 ethnographic texts from 60 societies. There is significant support that group singing is more prevalent than solo singing. The results also show that community size predicts group singing in only one of the samples (GJB). However, there is no significant support for social differentiation as a predictor of group singing.