Stefani A. Crabtree is Associate Professor of Social-Environmental Modeling in the Department of Environment and Society at Utah State University and an External Professor at the Santa Fe Institute. She has two Ph.D.s: one in anthropology (focus: archaeology) from Washington State University (2016) and one from the Maison des Sciences de l’Homme et l’Environnement from the Université de Franche-Comté (2017). She is a computational social scientist and complexity scientist whose research focuses on understanding how individual decisions, human behavior, ecological processes, and environmental conditions interact to produce large-scale patterns across space and through time.
Crabtree specializes in agent-based modeling, ecological and food-web modeling, network science, and computational approaches to coupled human-natural systems. Her work brings together methods from ecology, archaeology, anthropology, geography, and complex systems science to address problems in which human behavior and environmental processes cannot be understood independently. A central feature of her research is the development of models that represent interacting individuals, species, resources, and environments, allowing researchers to explore how local decisions and interactions generate system-level outcomes.
Her modeling expertise spans a range of applications, including ecosystem health, human health, resource management, resilience, human-environment interactions, migration, landscape change, and the dynamics of complex ecological and social systems. She has developed and applied models ranging from individual-based simulations of human movement and migration to ecological food webs describing interactions among humans, plants, animals, and other components of ecosystems. Her work is particularly focused on systems in which feedbacks, indirect effects, competing demands, and nonlinear interactions make conventional approaches insufficient.
Crabtree is a developer and practitioner of agent-based modeling techniques, using computational agents to represent individuals, households, communities, organizations, or other decision-making entities and allowing their interactions to generate emergent patterns. Her work has included the development of models of human movement and migration, resource use, settlement, social organization, and human responses to environmental change. She is also a co-author of Agent-Based Modeling for Archaeology: Simulating the Complexity of Societies, a widely used open-access introduction to agent-based modeling for researchers interested in applying computational simulation to complex social systems. The book and associated teaching materials provide practical guidance for designing, implementing, and interpreting agent-based models. Access the open source book here:
Agent-Based Modeling for Archaeology project and resources
Her work in food-web and ecosystem modeling examines humans as active components of ecological systems rather than as external disturbances. Crabtree has reconstructed food webs from archaeological and ethnographic data and developed approaches for incorporating human resource use into ecological network models. This work provides a framework for asking how changes in human behavior—including harvesting, hunting, cultivation, species introductions, and landscape management—can alter ecological structure and resilience. Her research has contributed to the emerging field of archaeoecology, which combines archaeological evidence with ecological theory and quantitative modeling to understand human-environment interactions over long timescales. To read more on her work, follow this link:
Santa Fe Institute overview of Crabtree’s food-web research
A related area of Crabtree’s work examines the feedbacks between ecosystem health and human health. Rather than treating human well-being and environmental conditions as separate systems, her research investigates how changes in one can propagate through the other. Her modeling approaches are designed to identify indirect effects, feedback loops, thresholds, trade-offs, and potential unintended consequences of human interventions in complex systems. This perspective is applicable to problems ranging from natural-resource management and conservation to public health and the resilience of communities facing environmental change.
Crabtree also develops network models of human-environment systems, including bipartite networks that describe the many ways humans interact with other species. Her Human Interactions with Other Species (HIOS) framework moves beyond conventional food-web approaches by representing not only consumption but also uses such as medicine, clothing, construction, fuel, transportation, ritual, ornamentation, companionship, and trade. These approaches make it possible to investigate how societies depend on collections of species, how multifunctional resources create competing demands, and how changes in one part of a human-environment system can propagate through the broader network.
Her research on human migration and movement combines computational modeling, geographic information systems, landscape analysis, high-performance computing, and Artificial Intelligence. In work on the initial human migration across Sahul—the ancient continent encompassing Australia, New Guinea, and Tasmania—Crabtree and collaborators used computational models and supercomputing to reconstruct potential movement corridors and identify the geographic and environmental constraints that shaped one of humanity’s earliest large-scale migrations. The work received the HPC Innovation Excellence Award for its potential to produce real-world benefits, the first time this was awarded for archaeology. For more information, follow this link:
Santa Fe Institute coverage of Crabtree’s Sahul migration modeling
A distinctive feature of Crabtree’s research is her use of the archaeological past as a source of empirical data for understanding complex systems. Archaeological records contain thousands of years of observations of humans responding to environmental variability, resource constraints, climate change, migration, disease, and social transformation. By converting these records into quantitative models, Crabtree uses the past as a kind of long-term natural laboratory for investigating resilience and adaptation. Her work asks not only what happened in the past, but why particular outcomes emerged and whether the mechanisms responsible for those outcomes can inform contemporary environmental and social challenges.
This approach has also resulted in research with relevance to environmental policy and natural-resource management. Crabtree’s work on the Martu of Western Australia demonstrated how human activities can be integral components of ecosystem dynamics and how changes in human presence and land management can propagate through ecological food webs. This research has contributed to policy discussions in Australia concerning Indigenous land management and the role of people in maintaining resilient ecosystems. Her research has subsequently been cited in Australian government policy, providing an example of how computational ecological and social-science research can move from academic modeling into applied decision-making.
Crabtree’s broader research program is united by a simple premise: many of the most consequential problems facing society are complex systems problems. Climate change, biodiversity loss, ecosystem degradation, migration, resource scarcity, public health, and human resilience all involve multiple interacting actors and processes operating at different spatial and temporal scales. In such systems, interventions can have indirect effects, produce unintended consequences, or generate feedbacks that are difficult to anticipate using conventional linear models. Agent-based models, network models, food webs, and other computational approaches provide tools for making these interactions explicit and exploring how alternative scenarios may unfold.
Crabtree has published in interdisciplinary and disciplinary journals including Proceedings of the National Academy of Sciences, Nature Human Behaviour, Antiquity, Ecological Modelling, American Antiquity, Human Ecology, Journal of Archaeological Science, Journal of Archaeological Method and Theory, and Physics Today. Her research has been recognized for its contributions to computational archaeology, ecological network science, and the study of human-environment systems.
She is also the author, with Iza Romanowska and Colin D. Wren, of Agent-Based Modeling for Archaeology: Simulating the Complexity of Societies, published by SFI Press, and the author of Thinking Through Archaeological Complexity, published by Routledge. Thinking Through Archaeological Complexity presents complexity science as a practical framework for understanding how individual actions and interactions generate large-scale social and environmental patterns, connecting agent-based modeling, network analysis, archaeology, ecology, and geography. For more information on her new book, follow this link:
Thinking Through Archaeological Complexity — Santa Fe Institute
Stefani grew up in the small town of Bend, Oregon, and before college had never set foot out of the continental United States. As an undergraduate she studied abroad in Paris, taking courses in Art History, Egyptology and the Archaeology of Islam at Paris Sorbonne Michelet. She was a Watson Fellow in 2004-2005, living in New Zealand, Samoa, India and Vietnam doing a multi-site ethnography on how women of indigenous cultures use traditional medicine in pregnancy and childbirth. In graduate school Stefani was an NSF graduate research fellow and a Chateaubriand fellow.
Stefani is interested in how complexity science can help us understand the archaeological past. Follow her on bluesky @StefaniCrabtree
Areas of expertise include:
- Agent-based and individual-based modeling
- Complex adaptive systems
- Ecological and human-centered food web modeling
- Network science and network analysis
- Coupled human-natural systems
- Ecosystem health and resilience
- Human health–environment interactions
- Human dimensions of climate and environmental change
- Resource use and competing demands
- Human migration and movement modeling
- Landscape and spatial modeling
- Computational social science
- Archaeological and historical modeling
- High-performance computing and large-scale simulation
- Scenario analysis and simulation-based experimentation
- Interdisciplinary model development and research design
Dr. Stefani A. Crabtree 
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