Evolutionary anthropology has traditionally focused on the study of small-scale, largely self-sufficient societies. The increasing rarity of these societies underscores the importance of such research yet also suggests the need to understand the processes by which such societies are being lost—what we call “modernization”—and the effects of these processes on human behavior and biology. In this article, we discuss recent efforts by evolutionary anthropologists to incorporate modernization into their research and the challenges and rewards that follow. Advantages include that these studies allow for explicit testing of hypotheses that explore how behavior and biology change in conjunction with changes in social, economic, and ecological factors. In addition, modernization often provides a source of “natural experiments” since it may proceed in a piecemeal fashion through a population. Challenges arise, however, in association with reduced variability in fitness proxies such as fertility, and with the increasing use of relatively novel methodologies in evolutionary anthropology, such as the analysis of secondary data. Confronting these challenges will require careful consideration but will lead to an improved understanding of humanity. We conclude that the study of modernization offers the prospect of developing a richer evolutionary anthropology, by encompassing ultimate and proximate explanations for behavior expressed across the full range of human societies.

China's domestic tourism industry has flourished since the mid-1990s, spreading wealth and infrastructure from cities to remote villages and presenting new opportunities for cultural exchange. This paper aims to determine the financial and cultural impacts of tourism on inheritance and marital patterns of the matrilineal Mosuo of south-west China. Data from household censuses and personal interviews show that Mosuo residing in tourist-impacted areas deviate more often from traditional matrilineal norms than Mosuo residing in areas removed from tourism. Households more frequently contain bilateral descendants in tourist-impacted areas, whereas they are more often strictly matrilineal in farming areas. Marital patterns also differ more from stated norms in tourist-impacted areas. I interpret differences as adaptive responses to variation in acquired wealth, arguing that cultural assimilation alone is unlikely to account for such differences. I argue that the results are consistent with the general hypothesis that the accumulation of wealth is inconsistent with matriliny and conclude that families remain important to the Mosuo, but in ways different from before.

To address claims of human exceptionalism, we determine where humans fit within the greater mammalian distribution of reproductive inequality. We show that humans exhibit lower reproductive skew (i.e., inequality in the number of surviving offspring) among males and smaller sex differences in reproductive skew than most other mammals, while nevertheless falling within the mammalian range. Additionally, female reproductive skew is higher in polygynous human populations than in polygynous nonhumans mammals on average. This patterning of skew can be attributed in part to the prevalence of monogamy in humans compared to the predominance of polygyny in nonhuman mammals, to the limited degree of polygyny in the human societies that practice it, and to the importance of unequally held rival resources to women’s fitness. The muted reproductive inequality observed in humans appears to be linked to several unusual characteristics of our species—including high levels of cooperation among males, high dependence on unequally held rival resources, complementarities between maternal and paternal investment, as well as social and legal institutions that enforce monogamous norms.

Significance: Greater autonomy afforded to women in matrilineal societies has been hypothesized to benefit women’s health. Among the Mosuo, a society with both matrilineal and patrilineal subpopulations, we found that gender disparities in chronic disease are not only ameliorated but reversed in matriliny compared with patriliny. Gender disparities in health and chronic disease can thus be tied directly to cultural influences on health, including inequalities in autonomy and resource access between men and women.