Greater Wealth Inequality, Less Polygyny: Rethinking the Polygyny Threshold Model

Monogamy appears to have become the predominant human mating system with the emergence of highly unequal agricultural populations that replaced relatively egalitarian horticultural populations, challenging the conventional idea—based on the polygyny threshold model—that polygyny should be positively associated with wealth inequality. To address this polygyny paradox, we generalize the standard polygyny threshold model to a mutual mate choice model predicting the fraction of women married polygynously. We then demonstrate two conditions that are jointly sufficient to make monogamy the predominant marriage form, even in highly unequal societies. We assess if these conditions are satisfied using individual-level data from 29 human populations. Our analysis shows that with the shift to stratified agricultural economies: (i) the population frequency of relatively poor individuals increased, increasing wealth inequality, but decreasing the frequency of individuals with sufficient wealth to secure polygynous marriage, and (ii) diminishing marginal fitness returns to additional wives prevent extremely wealthy men from obtaining as many wives as their relative wealth would otherwise predict. These conditions jointly lead to a high population-level frequency of monogamy

Nonmarket Cooperation in the Indigenous Food Economy of Taimyr, Arctic Russia: Evidence for Control and Benefit

Empirical data on food sharing in native Dolgan, Nganasan, and Nenets communities in Siberia provide evidence for hunter control over big game and fish, as well as likely benefits of inter-household sharing. Most food sharing occurs with kin and, thus, kin-selection-based nepotism cannot be ruled out. Reciprocal inter-household sharing at meals occurs less often. Social context is discussed

Sharing, Subsistence, and Social Norms in Northern Siberia

The majority of families in Ust’-Avam in northern Siberia are dependent on subsistence hunting, fishing, and trapping and have been part of a vertically integrated industrial economy in a remote area of the former Soviet Union. Thus, the results from behavioral games conducted there in 2003—the dictator game (DG), the ultimatum game (UG), and the third-party punishment game (TPG)—lend themselves to comparison with other indigenous hunter-gatherers, as well as with working communities in other nation-states

The Life History of Human Foraging: Cross-Cultural and Individual Variation

Human adaptation depends on the integration of slow life history, complex production skills, and extensive sociality. Refining and testing models of the evolution of human life history and cultural learning benefit from increasingly accurate measurement of knowledge, skills, and rates of production with age. We pursue this goal by inferring hunters’ increases and declines of skill from approximately 23,000 hunting records generated by more than 1800 individuals at 40 locations. The data reveal an average age of peak productivity between 30 and 35 years of age, although high skill is maintained throughout much of adulthood. In addition, there is substantial variation both among individuals and sites. Within study sites, variation among individuals depends more on heterogeneity in rates of decline than in rates of increase. This analysis sharpens questions about the coevolution of human life history and cultural adaptation

Linking Disparate Approaches to the Study of Social Norms: An Example from Northern Siberia

This article examines altruistic social norms among the Dolgans and the Nganasans in Arctic Siberia, drawing on and integrating experimental game theory and semiotic approaches. The article demonstrates the complementarity of these two methodologies in order to more fully understand how sharing is promoted over individual self-aggrandizement in a communal-resource property regime. Any theory of social norms should be of some practical benefit for solving current environmental dilemmas, as well as for increasing understanding of the factors lending sustainability to human-environment relationships. With that goal in mind, the article presents results of experimental games conducted in the Taimyr Autonomous Region in 2003, along with an analysis of indigenous communication (sayings, aphorisms, taboos, etc.) aimed at the promotion of altruistic social norms. A synthesis of the two approaches is outlined with implications for the broader literature on hunting peoples across the north and beyond

Changing Gender Roles and Economies in Taimyr

This article is an inquiry into the extent to which, and how, roles of men and women in indigenous communities in north-central Siberia have changed along with the changing economic and political context from the 1917 Communist Revolution to the post-Soviet era. The starting point for this investigation is archived data from the 1926/27 Polar Census of Siberia. Fieldwork conducted in the region in the 1990s and 2000s provides comparative materials. During this 80-year period, the development of centralized settlements and regional urban areas brought increasing professionalization of traditional economic activities and greater involvement of the indigenous population in civil service work. As a result, the flexibility of gender roles in the indigenous pre-Soviet economy was sacrificed in favor of work in state companies and organizations that followed gender contracts imposed following the general Soviet model. In the post-Soviet period, following the collapse of the Soviet planned economy greater flexibility in gender roles has been observed, along with increasing importance of informal exchange networks and reliance upon hunting, fishing and trapping as key inputs to local economies

Sexual Initiation Among Canadian Youth: A Model Comparison Approach of Evolutionary Hypotheses Shows Greatest Support for Extrinsic Mortality Cues, Intergenerational Conflict, and Early Life Psychosocial Stressors

Early life factors are associated with the timing of reproductive events in adolescence, but a variety of hypotheses (such as psychosocial acceleration theory, paternal investment theory, extrinsic mortality, internal prediction, and intergenerational conflict) propose different explanations for why this may occur. To compare between these theories, we use the National Longitudinal Survey of Children and Youth, an extensive, longitudinal survey of Canadian male and female youth (aged 14-15 in last wave) to identify variables that uniquely support these different models (n≈1200). We identify the best predictors of sexual initiation for each hypothesis and then use a model selection procedure to determine which set of variables has the most support. Results show that variables representing extrinsic mortality cues, intergenerational conflict, early life psychosocial stressors, and prenatal factors are included in the top models, while variables representing social support and unpredictability are represented in some of the top models. Variables representing the paternal investment theory were not included in any of the top models, suggesting limited support for this hypothesis. These results support many of the hypotheses that have been previously presented in the literature, suggesting that timing of sexual initiation may have multiple causal pathways

Life-History Factors Influence Teenagers’ Suicidal Ideation: A Model Selection Analysis of the Canadian National Longitudinal Survey of Children and Youth

Suicidality is an important contributor to disease burden worldwide. We examine the developmental and environmental correlates of reported suicidal ideation at age 15 and develop a new evolutionary model of suicidality based on life history trade-offs and hypothesized accompanying modulations of cognition. Data were derived from the National Longitudinal Survey of Children and Youth (Statistics Canada) which collected information on children’s social, emotional, and behavioral development in eight cycles between 1994 and 2009. We take a model selection approach to understand thoughts of suicide at age 15 (N ≈ 1,700). The most highly ranked models include social support, early life psychosocial stressors, prenatal stress, and mortality cues. Those reporting consistent early life stress had 2.66 greater odds of reporting thoughts of suicide at age 15 than those who reported no childhood stress. Social support of the primary caregiver, neighborhood cohesion, nonkin social support of the adolescent, and the number of social support sources are all associated with suicidal thoughts, where greater neighborhood cohesion and social support sources are associated with a reduction in experiencing suicidal thoughts. Mother’s prenatal smoking throughout pregnancy is associated with a 1.5 greater odds of suicidal thoughts for adolescents compared to children whose mother’s reported not smoking during pregnancy. We discuss these findings in light of evolutionary models of suicidality. This study identifies both positive and negative associations on suicidal thoughts at age 15 and considers these in light of adaptive response models of human development. Findings are relevant for mental health policy

Paying It Forward or Giving Back?: Women’s Sharing Networks in Siberia

Subsistence food sharing in Ust’-Avam (Taimyr Region, Russian Federation) is analyzed in light of Arctic research on sharing and current debate. Cultural traditions such as food sharing practices are widespread across indigenous communities in the Arctic and are arguably fundamental to the sustainability of indigenous Arctic cultures and their ability to buffer against environmental disequilibrium. Sharing diaries from 10 respondents over 12 weeks in August and October 2001, describe 162 distributions among 69 household dyads. Independent variables, including household relatedness, reciprocal sharing, and interaction effects, influence the documented food sharing pattern. Economic need and social association also influence sharing. Indicators of risk buffering are weaker than in two previous analyses of food sharing in Ust’-Avam that focus on primary distributions after the hunt and interhousehold meal sharing. Consideration of sharing by nonhunters provides an opportunity to examine explanatory hypotheses of food sharing, illustrating the nuances and robusticity of social ecology in indigenous subsistence economies

Indigenous Siberian Food Sharing Networks: Social Innovation in a Transforming Economy

The sustainability of indigenous communities in the Arctic, and the vulnerable households within, is in large part dependent on their continuing food security. A social food-sharing network within the Ust’-Avam community on the Taimyr Peninsula in northern Siberia is analyzed for underlying patterns of resilience and key evolutionarily stable strategies supporting cooperative behavior. Factors influencing the network include interhousehold relatedness, reciprocal sharing, and interaction effects. Social association also influences sharing. Evidence for multiple determinants of food sharing in this sample is discussed in reference to major evolutionary hypotheses and comparable studies. In sum, the findings illustrate the robustness of self-organizing distribution networks in an economic context of uncertainty