This article examines reasons for participation in warfare and tests a hypothesis concerning cultural rewards from war. Data supports this hypothesis. The authors also critique alternative theories of participation in warfare that draw on group selection and the risk of punishment.

The present research investigates the theory of universality in form and function in human song in a sample of people from 60 countries listening to music from 86 mainly small-scale societies. The aims are to document whether people 1) identify the social function of a song solely on form, 2) demonstrate form-function inferences, 3) use contextual aspects to distinguish song functions, and 4) use musical features to differentiate song functions. The authors claim support for the universal perception of song form-function in music listeners.

Using t-test, generalized linear models (GLMs) and Bayesian regression models in a sample of 1188 pre-industrial societies, this study explores the research question: Why have foraging, horticulture, and pastoralism persisted into the 20th and 21st century? The authors test the marginal hypothesis and the oasis hypothesis of agricultural intensification. The first hypothesis suggests that foragers persisted because foragers predominantly inhabited marginal habitats that were typically unsuitable for agricultural purposes. The second hypothesis suggests that intensive agriculture emerged in regions characterized by limited biodiversity and a dependable water supply not reliant on local rainfall. In addition, the authors test whether specific kinds of biodiversity (elephants, malaria, and tsetse flies) correlate with agricultural intensification in African societies. The results support the marginal and oasis hypotheses, but only marginally support the African hypothesis, since only tsetse fly has a significant negative correlation to agricultural intensification.

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.