High infant and child mortality rates are suggested to be one of the most enduring and important features of ancestral human environments, referred to as the Environment of Evolutionary Adaptedness (EEA). These rates contrast with the very low rates of infant and child mortality among many industrialized nations since the 19th and 20th centuries. The authors compare data from recent hunter-gatherer and agricultural societies, historical records, and non-human primates in attempt to quantitatively describe infant and child mortality rates during the EEA.

This article tests a hypothesis regarding patterns of infant care in non-industrial societies. The authors find that a consistent pattern of infant care that emphasizes mother-infant contact exists among hunter-gatherers and other non-industrial societies. These infant care practices differ from those found in the United states that do not promote extensive infant-mother contact.

For thousands of years, scholars have been theorizing about why human groups structure themselves the way they do, allowing more power and freedom to certain individuals and less to others. This article takes an evolutionist approach to that question, using a variety of mathematical models to predict changes in social organization throughout the evolutionary history of humanity and its ancestors, accounting for changes in brain size and global human populations. The authors validate their models using data from the ethnographic record. In general, they find that tendency towards hierarchy decreases with bigger brain size but increases with global population growth.

This paper is concerned with the variation in sexual behavior in humans. Authors test hypotheses regarding the relationships between sexual behaviors and beliefs concerning sex.

This thesis follows an evolutionary approach to explore the role of dancing in nuptial rituals across cultures. The overarching hypothesis is that dancing will play a role in courtship. To test this, the author suggests four hypotheses related to the presence of men and women dancing in nuptial rituals. None of these hypotheses were supported by the societies analyzed from eHRAF. This thesis concludes that dancing in nuptial rituals might play different purposes and that further research must be conducted to test other roles such as social bonding or cooperation effects.

The present research inquires into the effects, if any, that male status and power have on extramarital sex, parental investment, and polygyny. Using sexual selection theory, the hypothesis is that males in higher positions of power and status are more likely to engage in extramarital sexual activities and be in polygynous relationships was supported. There was no support for an association between male extramarital sex and parental investment.

Researchers tested the popular identity fusion theory, which states that while maintaining one’s own individual identity, a deep affinity with one’s group can contribute to sacrifice for that group, in conjunction with their own hypotheses, using a behavior economic experiment. The experiment looked at whether after rolling a die to determine which cup a coin was placed into, participants actually followed the rules, or favored themselves (by putting the coin into their own cups at a disproportionate rate). The findings state that while on average, the individual participants did indeed favor themselves, those with higher ingroup fusion were more likely to sacrifice coins to other members of their ‘ingroup.' The experiments were conducted in 8 culturally diverse field sites.

This study examines three human facial variables to assess facial attractiveness: symmetry, sex-typicality, and distinctiveness. The goal is to understand whether perceived facial attractiveness might explain human mate choice. The authors use Bayesian multilevel regression analyses and 72 standardized frontal facial landmarks to explore the structural aspects of opposite-sex facial attractiveness preferences for both females and males. They used a sample of 1,550 faces from 10 countries. The results show that 1) distinctiveness is negatively correlated with attractiveness, 2) symmetry does not have a significant association with attractiveness, and 3) sex-typicality is positively correlated with female facial attractiveness but not the other way around. The authors also used a model with body height and BMI, but only some cases had enough information. Although with limitations, their results show that a lower BMI is associated with higher perceived female attractiveness. There is no significant association between BMI and perceived male attractiveness.

Using a sample of 313 societies classified within 24 language phyla, authors put forward a statistical model based on climate data [specifically focused on the 10°C (50°F) winter temperature isotherm] to explain why dispersion of preindustrial language phyla is remarkably homogeneous even despite heterogeneous geographical dispersion of sampled preindustrial cultural groups. They suggest that temperature has been a barrier to migration.

This study examines differences in the ease of socialization for male and female children in preindustrial societies. Results support the hypothesis that the socialization of females is accomplished more easily than the socialization of males.