How is the evolution of language shaped by speaker population size? Through comparative data analyses of 153 language pairs from the Austronesian, Indo-European, and Niger-Congo language families, the authors find that the influence of population size on language evolution is not the same in the three language families. Only in Indo-European languages did a smaller population size of language-speakers significantly predict more word loss.

Using phylogenetic comparative methods, the study explores the evolution of kinship terminologies within 176 societies in Austronesian, Bantu, and Uto-Aztecan language families. The authors consider 18 theories in the anthropological record that suggests that change in kinship terminologies is predicted by some social structures: marriage, residence, and descent. Only 19 of the 29 statistical hypotheses are supported, while none of the theories are supported in all three language families. This statistical irregularity means that the results are lineage-specific, instead of showing a universal driver of change in kinship terminology types.

Aiming to better understand human demographic and dispersal history, the study uses Bayesian phylogenetic comparative methods to trace post-marital residence and cultural changes among 27 Indo-European and 135 Austronesian languages. They suggest that changes from uxorilocality to other types of residences (neolocality and virolocality) are more common than the inverse transitions. The results are generally supported with one exception: Austronesian societies have a higher rate of transition from neolocality to uxorilocality (1.5) than the other way around (0.9). Other relevant findings are that proto-Indo-European societies tend to follow virilocality, while proto-Malayo-Polynesian uxorilocality. There is a commonality for both language families to present instability of uxorilocality and unusual loss of uxorilocality.

Using ethnography, historical linguistics, paleoanthropology, and speech biomechanics, the present study examines the relationship between labiodentals and the post-Neolithic period with the introduction of agriculture and softer diets. The results offer support for the linguist, Charles Hockett's, hypothesis that the shift in bite configuration in the post-Neolithic period, as well as the persistence of overbite and overjet, facilitates and makes the articulation of labiodentals more prevalent. Using cross-cultural comparison, findings also reveal that societies that produce their food are more likely to evolve and keep labiodentals than those that are not food-producing. Contact with other societies is also a mode by which societies gain labiodentals. Lastly, the expansion of agricultural and food processing technology over time has been imperative to labiodental articulations.

The "equi-complexity hypothesis" suggests that there is an equal complexity across languages, meaning that there are constant trade-offs between different domains. Using phylogenetic modelling in a sample of 244 languages, this study follows a diachronic perspective to explore if there is an inversed coevolution within the grammatical coding of nominal and verbal domains. The results show that while there appears to be a coevolutionary relationship between some features of these two domains, there is no evidence to support the idea that all languages maintain an overall equilibrium of grammatical complexity. Rather, the correlation nominal and verbal domains vary between lineages. Austronesian languages do not show a coevolution between the domains. Sino-Tibetan languages seem to have a positive correlation while Indo-European languages appear to have a negative correlation, meaning that this inverse coevolution can be lineage specific.

Using phylogenetic modeling, the researchers test hypotheses for different sequences of political complexity among South-East Asian and Pacific Austronesian-speaking cultures. The research adds to an existing debate between sequential, incremental political evolution models and non-sequential models with larger increases in complexity. The results suggest support for a more sequential unilinear model.

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.

The authors compare language phylogenies and spatial distributions with folktale frequencies of Indo-European peoples in order to reconstruct their cultural transmission. A stronger association is found between folktale frequency and language phylogeny than has been proposed in earlier literature studies, indicating that vertical transmission is more influential on folktale distribution than horizontal transmission through spatial proximity. Finally, the frequencies of certain folktales appear to trace the ancestral divergences of Indo-European languages to a much deeper level than previously though, suggesting that folktales are representative of broader features of culture, rather than recent literary inventions.

This article employs a phylogenetic approach to explore traits that might be associated with the cultural transmission of the "witchcraft phenotype" across Bantoid and Bantu ethnolinguistic groups. The authors define the witchcraft phenotype as a set of interlinked traits related to witchcraft beliefs within a society, showing both cross-cultural similarities and regional variations. Despite the widespread historical and geographical presence of witchcraft beliefs, little is known about their evolution and transmission. The article's analysis focuses on the possible ancestral transmission of these traits and their coevolution. The authors suggest that witchcraft phenotypes are often intertwined with beliefs in ancestors, spirits, gods, and other supernatural entities, and like other cultural traits, they can evolve through various mechanisms. Their findings indicate support for phylogenetic transmission of some traits, such as the use of poison to detect witchcraft guilt, but show that other factors such as age and gender do not show evidence of historical transmission.

This paper examines the enormous variation in linguistic diversity among Pacific Islands by testing its relationship with various environmental variables put forth in several common theories of language richness. The researchers identify variables relating to land area and island isolation as accounting for about half of variation in linguistic diversity, suggesting that the other half is a result of complex social factors.