Jacob Freeman

Toward a theory of punctuated subsistence change

Significance The questions of how, when, and why humans transitioned from hunting and gathering to food production are important to understand the evolution and sustainability of agricultural economies. We explore cross-cultural data on human subsistence with multivariate techniques and interpret the results from the perspective of human societies as complex adaptive systems. We gain insight into several controlling variables that may inordinately influence the possibilities for subsistence change and into why the forager–farmer transition occurred quickly in some cases and more gradually in others. Discourse on the origins and spread of domesticated species focuses on universal causal explanations or unique regional or temporal trajectories. Despite new data as to the context and physical processes of early domestication, researchers still do not understand the types of system-level reorganizations required to transition from foraging to farming. Drawing upon dynamical systems theory and the concepts of attractors and repellors, we develop an understanding of subsistence transition and a description of variation in, and emergence of, human subsistence systems. The overlooked role of attractors and repellors in these systems helps explain why the origins of agriculture occurred quickly in some times and places, but slowly in others. A deeper understanding of the interactions of a limited set of variables that control the size of attractors (a proxy for resilience), such as population size, number of dry months, net primary productivity, and settlement fixity, provides new insights into the origin and spread of domesticated species in human economies.

Nonlinear Effects of Cognitive Ability on Economic Productivity

Cognitive capitalism theory argues that the positive effects of cognitive ability on economic productivity should increase nonlinearly, with increases in ability amplifying increases in productivity. The theory was tested using country-level indicators of cognitive ability and productivity. Cognitive ability was based on international student assessments (e.g., Program for International Student Assessment, PISA), and productivity was based on economic inputs (e.g., scientific achievements and competitiveness) and outputs (e.g., gross domestic product). As predicted, the effects of cognitive ability on all productivity measures increased nonlinearly at higher levels of ability, suggesting that higher ability levels disproportionately boost a nation’s productivity. The findings are discussed in light of standard theories of cognitive ability (e.g., Spearman’s law of diminishing returns and differentiation theories), and suggest that interventions that boost cognitive ability can have large, amplifying effects on economic productivity.

The Socioecology of Territory Size and a "Work-Around" Hypothesis for the Adoption of Farming.

This paper combines theory from ecology and anthropology to investigate variation in the territory sizes of subsistence oriented agricultural societies. The results indicate that population and the dependence of individuals within a society on “wild” foods partly determine the territory sizes of agricultural societies. In contrast, the productivity of an agroecosystem is not an important determinant of territory size. A comparison of the population-territory size scaling dynamics of agricultural societies and human foragers indicates that foragers and farmers face the same constraints on their ability to expand their territory and intensify their use of resources within a territory. However, the higher density of food in an agroecosystem allows farmers, on average, to live at much higher population densities than human foragers. These macroecological patterns are consistent with a “work-around hypothesis” for the adoption of farming. This hypothesis is that as residential groups of foragers increase in size, farming can sometimes better reduce the tension between an individual’s autonomy over resources and the need for social groups to function to provide public goods like defense and information.

Marking and making differences: Representational diversity in the U.S. Southwest

Abstract Diversity is generally valued, although it sometimes contributes to difficult social situations, as is recognized in recent social science literature. Archaeology can provide insights into how diverse social situations play out over the long term. There are many kinds of diversities, and we propose representational diversity as a distinct category. Representational diversity specifically concerns how and whether differences are marked or masked materially. We investigate several archaeological sequences in the U.S. Southwest. Each began with the coming together of populations that created situations of unprecedented social diversity; some resulted in conflict, others in long-term stability. We trace how representational diversity changed through these sequences. Specifically, we review the transregional Kayenta migration to the southern Southwest and focus empirical analyses on regional processes in the Cibola region and on painted ceramics. Results show that, initially, representational diversity increased above and beyond that caused by the combination of previously separate traditions as people marked their differences. Subsequently, in some instances, the diversity was replaced by widespread homogeneity as the differences were masked and mitigated. Although the social causes and effects of diversity are many and varied, long-term stability and persistence is associated with tolerance of a range of diversities.

Synchronization of energy consumption by human societies throughout the Holocene

Significance We report coincident changes in the consumption of energy by human populations over the last 10,000 y—synchrony—and document patterns consistent with the contemporary process of globalization operating in the past. Our results suggest that the process of globalization may display great antiquity among our species, and this knowledge provides an entry point for integrating insights from archaeological research into discussions on the long-term consequences of globalization for building sustainable societies. Our results demonstrate the potential for archaeological radiocarbon records to serve as a basis for millennial-scale comparisons of human energy dynamics and provide a baseline for further cross-cultural research on the long-term growth and decline trajectories of human societies. We conduct a global comparison of the consumption of energy by human populations throughout the Holocene and statistically quantify coincident changes in the consumption of energy over space and time—an ecological phenomenon known as synchrony. When populations synchronize, adverse changes in ecosystems and social systems may cascade from society to society. Thus, to develop policies that favor the sustained use of resources, we must understand the processes that cause the synchrony of human populations. To date, it is not clear whether human societies display long-term synchrony or, if they do, the potential causes. Our analysis begins to fill this knowledge gap by quantifying the long-term synchrony of human societies, and we hypothesize that the synchrony of human populations results from (i) the creation of social ties that couple populations over smaller scales and (ii) much larger scale, globally convergent trajectories of cultural evolution toward more energy-consuming political economies with higher carrying capacities. Our results suggest that the process of globalization is a natural consequence of evolutionary trajectories that increase the carrying capacities of human societies.

The Effects of Revenue and Social Capital on Collective Governance: Implications for Political Complexity

We evaluate two models that may explain variation in the inclusiveness of governments and their ability to provision public goods. The revenue model predicts that a government’s source of revenue determines whether elites invest in effective bureaucracy and the provision of public goods that benefit wide swaths of society or the extraction of resources from society to benefit a limited network. In this model, a cooperative society with high social capital is an outcome of effective, collective government. The combined model predicts that social capital has a semi-independent causal effect, in addition to revenue, on the inclusiveness of governments. Our results indicate that the combined model of collective governance fits the data on U.S. states better than the revenue model alone. The combined model of governance predicts that revenue and social capital moderate the population size–political complexity relationship, and data from the U.S. states are consistent with these predictions.

Diversity, reciprocity, and the emergence of equity-inequity tradeoffs

Reciprocity is a core institution that allows diverse individuals to engage in collective action. Collective action is essential to meet the goals of sustainable development. The twin goals of sustainable development are to protect the well-being of individuals and ecosystems in ways that are socially just. These twin goals constitute the win-win paradigm. However, tradeoffs in socialecological systems may limit collective action and, thus, make the win-win paradigm difficult to achieve. To understand how and why this is the case, we need a better understanding of tradeoffs. In this paper, we use a model of specialization and exchange in an agroecological system to propose a typology of tradeoffs: functional, robustness-vulnerability, and equity-inequity tradeoffs. We especially focus on how the interaction of diverse capaibilities, resource abundance, and reciprocity in a social-agroecological system generates equity-inequity tradeoffs. In our model, a simple diversity of capabilities (even among actors with the same goals) who engage in reciprocal exchange produces equity-inequity tradeoffs. Equity-inequity tradeoffs underlie conflicts of interest and may favor winner take all scenarios, as opposed to win-wins. However, our analysis is not all bad news. If resources are abundant enough, we observe the potential for qualified win-wins.