Human Behavioral Ecology
1. Introduction to Human Behavioral Ecology
In the pages that follow, we hope to show the fertility of the HBE approach as an integrative conceptual framework for anthropology.
This interest in the fitness-enhancing benefits of behavior helps to distinguish HBE from some versions of sociocultural anthropology in which the search for meaning and symbolism takes precedence. To many HBE researchers, the ultimate goal of any explanation is to show that a cultural practice or belief has adaptive value as a solution to a recurrent environmental problem. A subsidiary goal is to understand the ecological factors that lead to variation in adaptive strategies between different groups of people living in the same regional environment. Economic and ecological models are being increasingly used to analyze these between-group variations, using data from both living and past societies.
The approach has its roots in other disciplines, principally ecology, genetics, and economics. It is based on a love of natural history and a fascination with the diversity of human cultural adaptations to environments around the world. The HBE perspective seeks to explain behavioral variation in terms of the adaptive challenges that faced our hunter-gatherer ancestors as they migrated out of Africa and settled for thousands of years in different types of habitats. These challenges include finding a mate, foraging for food, acquiring social status, eluding enemies, and avoiding disease and parasites.
2. Basic Concepts in Human Behavioral Ecology
Behavioral ecology is considered a field of evolutionary biology. The name itself conveys the combining of behavior and ecology. Drawing from its “parent” disciplines, human behavioral ecology is focused on the adaptive nature of learning, behavior, and cognition in the genus Homo. In terms of comparing human behavior with the rest of the animal kingdom, there lies a continuum of the nature of behavioral flexibility and the time over which natural selection has shaped behavior and cognition. The first comparative studies often draw from existing behavioral and evolutionary theory in the aforementioned “parent” disciplines and work on the assumption that humans are still subject to the forces of natural selection. This approach has its benefits and drawbacks, but it is reasonable to argue that an understanding of human behavior is best wrought through comparisons of humans and their hominid/paleolithic ancestors.
Human behavioral ecology employs hypotheses and methods from evolutionary biology to generate and test theories about human behavior. Evolutionary ecology is concerned with the adaptive problems faced by organisms and the behavioral and ecological solutions to these problems. It assumes that natural selection has crafted behaviors and cognitions that enhance individual fitness relative to the alternative behaviors or cognitions available at the time. Fitness here is measured in terms of reproductive success. Thus, the decisions made by individuals have direct and indirect consequences for the number of offspring they produce.
3. Applications of Human Behavioral Ecology
Optimization models are heuristic devices designed to help solve complex behavioral problems and should be evaluated not only on whether the predicted behavior is found in the real world but also on the creativity of the model used to explain the behavior. Some of the most creative applications of human behavioral ecology to understanding behavior have been in the field of life history theory. Life history theory, or the allocation of resources to various functions such as growth, reproduction, and maintenance, maturation, and survival, is fundamentally an allocation problem. Models predicting how organisms will allocate scarce resources, capital, and energy to competing alternative investment options in a way that maximizes fitness have been very successful in explaining variation in human economic and reproductive behavior. For example, much ethnographic work has shown that variation in subsistence effort among small-scale societies worldwide is explained by differences in market integration and access to high return resources. Studies have demonstrated that the household level of caloric investment at a market price for a main protein food is a good indicator of the return rate of foraging in various activities. A study by Jim Woodburn (1982) showed that Hadza foragers invested more work effort in honey production during seasons when return rates for honey were relatively higher. High return rate activities are analogous to patches in foraging models, and Woodburn’s study showed a quite intuitive result that Hadza households invested more labor in the honey patch during high return seasons. Similar studies have shown that when return rates are high on resources that are risky and difficult to extract, households will invest more labor and collect the resource at a rate closer to its sustainable rate. An analysis using a model from patch leave strategies in optimal foraging theory showed that modern Ache hunter-gatherers were indeed collecting wild game at very high rates and were likely to deplete the resource in a short period.
Human behavioral ecology can provide a general framework for developing theories about human behavior. Two of the most important features of the framework are its emphasis on examining variation—that is, cross-cultural differences in behavior—and its use of optimality models and the concept of trade-offs to explain the observed variation. Optimality models have been used in economics and biology to explain why agents choose one course of action rather than another. An optimization model has three main components: 1) a clear understanding of the currency to be maximized (e.g., energy, time, resources, offspring survival); 2) a statement of the various constraints that affect the actor’s ability to maximize the chosen currency; and 3) a careful analysis of alternatives regarding how the currency may be maximized in light of the constraints.
4. Case Studies in Human Behavioral Ecology
Migration by Michael Bonner is an engaging account of the demography, economics, government, and ideology of migration in and from eastern Anatolia from the 16th until the early 20th century. It examines a large and underappreciated subject within a regional framework, on the basis of a wide range of sources including British consular archives and the correspondence of the Ottoman central government. Migration was a response to both environmental and economic constraints in highland districts of eastern Anatolia. Demographic pressure on land caused increasing activity in long-distance migration to more fertile locations within the empire, or outmigration to southern Russia or Iran. A second phase of migration began in the early 19th century when tribal chieftains unable to adjust to the incorporation of their lands into the Ottoman state moved their tribes and dependents outside the eastern frontier to settle in newly conquered territories and create Kurdish emirates. Bonner examines the long process by which eastern Anatolia was thereby progressively depopulated and Kurdisized. Highland and long-distance migration were not simply flight from poverty; rather they were undertaken by people who were better off and more enterprising than the general rural population, and retained a sense of regional identity and cohesion. In the last third of the 19th century outmigration from eastern Anatolia gained an international character, with Transcaucasia and the newly opened lands of the Ottoman Danube and southwestern Russia becoming destinations of large numbers of Armenian and Kurdish economic migrants. Migration between the 16th and early 20th century brought an end to the isolation of eastern Anatolia within the wider history of the Islamic world and the Middle East, and linked it to both newer Russian and Persian imperialism, and the Christian Europe ascending to hegemony over the modern Near East.
5. Future Directions in Human Behavioral Ecology
One of the great versatilities of human behavioral ecology is that it is inherently an interdisciplinary enterprise. As Hewlett points out with respect to the field site of Butan, at times this can mean acting as “one person wearing many hats or one institution with a variety of specialists. The interdisciplinary nature of HBE can also mean fruitful collaboration between different people at different institutions: for example, a human behavioral ecologist and a conservation biologist analyzing human impacts on environmental degradation, or a demographer and a behavioral ecologist working to understand variation in population growth rates among different human societies. Beyond this, the field is also ripe for collaboration with workers in other sub-disciplines of anthropology; cross-pollination between HBE and cultural anthropology could be especially fertile. Hopefully these future endeavours will bring a soaring trajectory of growth for human behavioral ecology making it an indispensable tool for understanding human behaviour.
