Paul L Hooper

University of New Mexico | UNM · Department of Anthropology

What conditions favour egalitarianism, that is, muted hierarchies with relatively equal distributions of resources? Here, we combine the hawk–dove and prisoner’s dilemma games to model the effects of economic defensibility, costs of competition and gains from cooperation on egalitarianism, operationalized as the absence of hawks. We show that a ‘le...

Human civilizations depend on the climate. Changes in climate affect the production of food and other resources that support populations and their economies. We asked whether the millennium-scale climate cooling events identified by Gerard Bond predicted social complexity in the Seshat cross-cultural database. The results show that social complexit...

Mathematical models based on evolutionary and ecological principles can help explain and predict variation in political organization and inequality across societies. This chapter introduces five major themes in human behavioral ecology that contribute to this goal. First, vertical power relationships between dominants and subordinates arise when re...

At the headwaters of the Yenisei River in Tuva and northern Mongolia, nomadic pastoralists move between camps in a seasonal rotation that facilitates their animals' access to high-quality grasses and shelter. The use and informal ownership of these camps depending on season helps illustrate evolutionary and ecological principles underlying variatio...

We examine various forms of helping behavior among Tsimane Amerindians of Bolivia, focusing on the provision of shelter, childcare, food, sickcare, cultural influence, and traditional story knowledge. Kin selection theory traditionally explains nepotistic nurturing of youth by closely related kin. However, less attention has been given to understan...

Industrialized environments, despite benefits such as higher levels of formal education and lower rates of infections, can also have pernicious impacts upon brain atrophy. Partly for this reason, comparing age-related brain volume trajectories between industrialized and non-industrialized populations can help to suggest lifestyle correlates of brai...

Although still prevalent in many human societies, the practice of cousin marriage has precipitously declined in populations undergoing rapid demographic and socioeconomic change. However, it is still unclear whether changes in the structure of the marriage pool or changes in the fitness-relevant consequences of cousin marriage more strongly influen...

While it is commonly assumed that farmers have higher, and foragers lower, fertility compared to populations practicing other forms of subsistence, robust supportive evidence is lacking. We tested whether subsistence activities—incorporating market integration—are associated with fertility in 10,250 women from 27 small-scale societies and found con...

Poor oral health is associated with cardiovascular disease and dementia. Potential pathways include sepsis from oral bacteria, systemic inflammation, and nutritional deficiencies. However, in post-industrialized populations, links between oral health and chronic disease may be confounded because the lower socioeconomic exposome (poor diet, pollutio...

Background In industrialized populations, low male testosterone is associated with higher rates of cardiovascular mortality. However, coronary risk factors like obesity impact both testosterone and cardiovascular outcomes. Here, we assess the role of endogenous testosterone on coronary artery calcium in an active subsistence population with relativ...

Over 80% of adolescents worldwide are insufficiently active, posing massive public health and economic challenges. Declining physical activity (PA) and sex differences in PA consistently accompany transitions from childhood to adulthood in post-industrialized populations and are attributed to psychosocial and environmental factors. An overarching e...

The severity of infectious disease outbreaks is governed by patterns of human contact, which vary by geography, social organization, mobility, access to technology and healthcare, economic development, and culture. Whereas globalized societies and urban centers exhibit characteristics that can heighten vulnerability to pandemics, small-scale subsis...

In many populations, the apolipoprotein-ε4 (APOE-ε4) allele increases the risk for several chronic diseases of aging, including dementia and cardiovascular disease; despite these harmful effects at later ages, the APOE-ε4 allele remains prevalent. We assess the impact of APOE-ε4 on fertility and its proximate determinants (age at first reproduction...

We examine various forms of helping behaviour among Tsimane Amerindians of Bolivia, focusing on the provision of shelter, childcare, food, sickcare, cultural influence and traditional story knowledge. Kin selection theory traditionally explains nepotistic nurturing of youth by closely related kin. However, less attention has been given to understan...

This chapter presents an evolutionary framework for understanding why there are bidirectional relationships between sex hormones and exercise and how these relationships are predicted to influence women’s behavior and health. An evolutionary perspective highlights the importance of understanding how physiology and behavior have been shaped by natur...

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 neverth...

Little is known about brain aging or dementia in nonindustrialized environments that are similar to how humans lived throughout evolutionary history. This paper examines brain volume (BV) in middle and old age among two indigenous South American populations, the Tsimane and Moseten, whose lifestyles and environments diverge from those in high-incom...

Over 80% of adolescents worldwide are insufficiently active, posing massive public health and economic challenges. Declining physical activity (PA) and sex differences in PA consistently accompany transitions from childhood to adulthood in post-industrialized populations and are attributed to psychosocial and environmental factors. An overarching e...

The author list and contributions statement for ‘Repercussions of patrilocal residence on mothers’ social support networks among Tsimane forager–farmers’ was corrected.

A growing body of work has addressed human adaptations to diverse environments using genomic data, but few studies have connected putatively selected alleles to phenotypes, much less among underrepresented populations such as Amerindians. Studies of natural selection and genotype–phenotype relationships in underrepresented populations hold potentia...

Cooperation in food acquisition is a hallmark of the human species. Given that costs and benefits of cooperation vary among production regimes and work activities, the transition from hunting-and-gathering to agriculture is likely to have reshaped the structure of cooperative subsistence networks. Hunter–gatherers often forage in groups and are gen...

While it is commonly thought that patrilocality is associated with worse outcomes for women and their children due to lower social support, few studies have examined whether the structure of female social networks covaries with post-marital residence. Here, we analyse scan sample data collected among Tsimane forager–farmers. We compare the social g...

Introduction: The Tsimane forager-horticulturalists of Bolivia are highly physically active, carry high infectious disease burdens, and have the lowest reported population levels of coronary artery calcium (CAC), as well as relatively low cholesterol (LDL, HDL, total) levels. In industrialized populations, lipoprotein(a)—Lp(a)— is strongly predicti...

Introduction: We evaluated the prevalence of dementia and mild cognitive impairment (MCI) in indigenous Tsimane and Moseten, who lead a subsistence lifestyle. Methods: Participants from population-based samples ≥ 60 years of age (n = 623) were assessed using adapted versions of the Modified Mini-Mental State Examination, informant interview, lon...

Brain atrophy is correlated with risk of cognitive impairment, functional decline, and dementia. Despite a high infectious disease burden, Tsimane forager-horticulturists of Bolivia have the lowest prevalence of coronary atherosclerosis of any studied population and present few cardiovascular disease (CVD) risk factors despite a high burden of infe...

In high-income countries, one's relative socio-economic position and economic inequality may affect health and well-being, arguably via psychosocial stress. We tested this in a small-scale subsistence society, the Tsimane, by associating relative household wealth (n=871) and community-level wealth inequality (n=40, Gini = 0.15 – 0.53) with a range...

Nomadic pastoralism persists at a substantial scale in Tuva and neighboring regions of Inner Asia. Tuvan pastoral lifeways reflect adaptations to both local environments and current economic realities. Much of our quantitative understanding of the economics of Tuvan nomads is derived from data collected in the first half of the 20th century. Accord...

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 comparative cross-species perspective, humans experience unique physical impairments with potentially large consequences. Quantifying the burden of impairment in subsistence populations is critical for understanding selection pressures underlying strategies that minimize risk of production deficits. We examine among forager-horticulturalists whe...

Normal human body temperature (BT) has long been considered to be 37.0°C. Yet, BTs have declined over the past two centuries in the United States, coinciding with reductions in infection and increasing life expectancy. The generality of and reasons behind this phenomenon have not yet been well studied. Here, we show that Bolivian forager-farmers (n...

Inequality or skew in reproductive success (RS) is common across many animal species and is of long-standing interest to the study of social evolution. However, the measurement of inequality in RS in natural populations has been challenging because existing quantitative measures are highly sensitive to variation in group/sample size, mean RS, and a...

Humans experience unique physical impairments with potentially severe economic consequences. Quantifying the burden of impairment in subsistence populations is critical for understanding selection pressures underlying strategies that minimize risk of production deficits. We examine among forager-horticulturalists whether compromised bone strength (...

Paternal provisioning among humans is puzzling because it is rare among primates and absent in nonhuman apes and because emergent provisioning would have been subject to paternity theft. A provisioning “dad” loses fitness at the hands of nonprovisioning, mate-seeking “cads.” Recent models require exacting interplay between male provisioning and fem...

A brief ethnographic description of leadership in Tsimane' communities in lowland Bolivia in the 20th century.

This article provides a foundational understanding of the first demographic transition underlying the evolved biology of aging in our species. Its goal is to review the available evidence regarding the evolution of human aging, with a particular focus on middle and old age. Knowledge of this evolutionary history and variability across human groups...

This chapter provides a theoretical foundation for the thesis that the social dynamics occurring in the context of economically defensible resources are key generators of large-scale political integration and hierarchy in human societies. This model integrates evolutionary models of economic defensibility, cooperation, punishment, and political hie...

This chapter presents an evolutionary framework for understanding why there are bidirectional relationships between sex hormones and exercise, and how these relationships are predicted to influence women’s behavior and health. An evolutionary perspective highlights the importance of the ways physiology and behavior have been shaped by natural selec...

Despite humans’ and chimpanzees’ shared evolutionary history and many common characteristics, patterns of mating and parental investment in the two species are remarkably dissimilar. These dissimilarities have a profound impact on the nature of social relationships between the sexes in each species. We present an evolutionary and ecological framewo...

The Tsimane Health and Life History Project, an integrated bio-behavioral study of the human life course, is designed to test competing hypotheses of human life-history evolution. One aim is to understand the bidirectional connections between life history and social behavior in a high-fertility, kin-based context lacking amenities of modern urban l...

The degree to which prehispanic societies in the northern upland Southwest were hierarchical or egalitarian is still debated and seems likely to have changed through time. This paper examines the plausibility of village-spanning polities in the northern Southwest by simulating the coevolution of hierarchy and warfare using extensions to the Village...

Supplemental Experimental Procedures Tables S1–S4

Women exhibit greater morbidity than men despite higher life expectancy. An evolutionary life history framework predicts that energy invested in reproduction trades-off against investments in maintenance and survival. Direct costs of reproduction may therefore contribute to higher morbidity, especially for women given their greater direct energetic...

Social organisms sometimes depend on help from reciprocating partners to solve adaptive problems [1], and individual cooperation strategies should aim to offer high supply commodities at low cost to the donor in exchange for high demand commodities with large return benefits [2, 3]. While such market dynamics have been documented in some animals [4...

Networks of neuronal synapses are the fundamental basis for making and retaining memory. Reduced synapse number and quality correlates with loss of memory in dementia. Heat shock factor 1 (HSF1), the major transcription factor regulating expression of heat shock genes, plays a central role in proteostasis, in establishing and sustaining synaptic fi...

The role that social status plays in small-scale societies suggests that status may be important for understanding the evolution of human fertility decisions, and for understanding howsuch decisions play out in modern contexts. This paper explores whether modelling competition for status—in the sense of relative rank within a society—can help shed...

In foraging and other productive activities, individuals make choices regarding whether and with whom to cooperate, and in what capacities. The size and composition of cooperative groups can be understood as a self-organized outcome of these choices, which are made under local ecological and social constraints. This article describes a theoretical...

This PDF file includes: Materials and Methods Supplementary Results Figures S1-S8 Tables S1-S7 Captions for databases S1 to S2 References Other Supplementary Materials for this manuscript includes the following: Database S1: AFRdata.csv Database S2: IPIdata.csv

Parasitic worms influence human fecundity Parasitic worms infect 2 billion people globally. Mostly, such infections are symptomless and individual worm burdens are low. Blackwell et al. monitored the fecundity of Tsimane women in Bolivia. These women have on average of 10 children in their lifetimes. However, if they had successive hookworm infecti...

Leadership is an active area of research in both the biological and social sciences. This review provides a transdisciplinary synthesis of biological and social-science views of leadership from an evolutionary perspective, and examines patterns of leadership in a set of small-scale human and non-human mammalian societies. We review empirical and th...

Sharing and exchange are common practices for minimizing food insecurity in rural populations. The advent of markets and monetization in egalitarian indigenous populations presents an alternative means of managing risk, with the potential impact of eroding traditional networks. We test whether market involvement buffers several types of risk and re...

Objectives: We investigate whether age profiles of Tsimane forager-horticulturalists’ reported skill development are consistent with predictions derived from life history theory about the timing of productivity and reproduction. Previous studies of forager skill development have often focused on a few abilities (e.g. hunting), and neglected the bro...

This chapter examines causal processes underlying change in demographic outcomes among the Tsimane of lowland Bolivia. Prospective data collected between 2002 and 2010 shows that the loss of an infant leads to an earlier progression to the next birth, as do prospective measures of maternal health. The total fertility rate is about 8.8, but greater...

The embodied-capital theory generalizes existing life history theory by treating the processes of growth, development, and maintenance as investments in stocks of somatic or embodied capital. The theory provides a means of understanding relationships between economic behavior, social behavior, and demographic traits such as fertility and survival....

Transfers of resources between generations are an essential element in current models of human life-history evolution accounting for prolonged development , extended lifespan and menopause. Integrating these models with Hamilton's theory of inclusive fitness, we predict that the interaction of biological kinship with the age-schedule of resource pr...

S1. Details on data collection and preparation S2. Details on the statistical analysis S3. Supplementary tables

Objectives We investigate whether age profiles of Tsimane forager-horticulturalists' reported skill development are consistent with predictions derived from life history theory about the timing of productivity and reproduction. Previous studies of forager skill development have often focused on a few abilities (e.g. hunting), and neglected the broa...

Background and objectives: Low social status increases risk of disease due, in part, to the psychosocial stress that accompanies feeling subordinate or poor. Previous studies report that chronic stress and chronically elevated cortisol can impair cardiovascular and immune function. We test whether lower status is more benign in small-scale, relativ...

The human species is an outlier in terms of demographic characteristics including lifespan, the duration of development, and menopause. Human social relationships—including support from extended family, cooperative pair-bonds between men and women, biparental care, and extensive cooperation between non-relatives—are likewise features that set human...

Reciprocity is a vital feature of social networks, but relatively little is known about its temporal structure or the mechanisms underlying its persistence in real world behavior. In pursuit of these two questions, we study the stationary and dynamical signals of reciprocity in a network of manioc beer (Spanish: chicha; Tsimane’: shocdye’) drinking...

Reciprocity is a vital feature of social networks, but relatively little is known about its temporal structure or the mechanisms underlying its persistence in real world behavior. In pursuit of these two questions, we study the stationary and dynamical signals of reciprocity in a network of manioc beer (Spanish: chicha; Tsimane': shocdye') drinking...

Reciprocity is a vital feature of social networks, but little is known about its structure in real world behavior, or the mechanisms underlying its persistence. In pursuit of these two questions, we study the stationary and dynamical signals of reciprocity in a network of manioc beer drinking events in a Tsimane' village in lowland Bolivia. At the...

Human kin cooperation is universal, leading researchers to label humans as “cooperative breeders.” Despite widespread interest in human cooperation, there has been no systematic study of how household economic decision making occurs. We document age and sex profiles of task delegation by parents to children ages 4–18 among Bolivian forager-horticul...

From evolutionary and economic points of view, it is useful to consider what makes religious institutions valuable to their adherents and propagators. What are the benefits that religions provide? What costs do they impose? And how do these benefits and costs vary with their content and the context in which they are practiced? One recurring benefit...

Herein, we propose that viral infection can induce a deficient cell stress response and thereby impairs stress tolerance and makes tissues vulnerable to damage. Having a valid paradigm to address the pathological impacts of viral infections could lead to effective new therapies for diseases that have previously been unresponsive to intervention. Ho...

Humans are the longest living and slowest growing of all primates. Although most primates are social, humans are highly cooperative and social in ways that likely co-evolved with the slow human life history. In this paper we highlight the role of resource transfers and non-material assistance within and across generations in shaping low human morta...

This work constitutes an integrated analysis of the Tsimane' economic subsistence system. Its analyses are guided by a body of evolutionary theory which posits that life history traits, the structure of social relationships, and nature of economic production co-evolve in patterned and predictable ways. This theory specifically suggests that, for hu...

We present an agent-based model for voluntaristic processes allowing the emergence of leadership in small-scale societies, parameterized to apply to Pueblo societies of the northern US Southwest between AD 600 and 1300. We embed an evolutionary public-goods game in a spatial simulation of household activities in which agents, representing household...

Xenohormesis is a biological principle that explains how environmentally stressed plants produce bioactive compounds that can confer stress resistance and survival benefits to animals that consume them. Animals can piggyback off products of plants' sophisticated stress response which has evolved as a result of their stationary lifestyle. Factors el...

This paper presents a new two-sex learning- and skills-based theory for the evolution of human menopause. The theory proposes that the role of knowledge, skill acquisition, and transfers in determining economic productivity and resource distribution is the distinctive feature of the traditional human ecology that is responsible for the evolution of...

We present empirical measures of wealth inequality and its intergenerational transmission among four horticulturalist populations. Wealth is construed broadly as embodied somatic and neural capital, including body size, fertility and cultural knowledge, material capital such as land and household wealth, and relational capital in the form of coalit...

Social organization among human foragers is characterized by a three-generational system of resource provisioning within families, long-term pair-bonding between men and women, high levels of cooperation between kin and non-kin, and relatively egalitarian social relationships. In this paper, we suggest that these core features of human sociality re...

Origins of Egalitarianism Wealthy contemporary societies exhibit varying extents of economic inequality, with the Nordic countries being relatively egalitarian, whereas there is a much larger gap between top and bottom in the United States. Borgerhoff Mulder et al. (p. 682 ; see the Perspective by Acemoglu and Robinson ) build a bare-bones model de...