Evolution of Human Reproductive Strategies

Behavioural Ecology of Parental Care

Karo woman and child (North Sumatra, 2004)

My primary research program since I was a PhD student in Biocultural Anthropology at the University of Washington, Seattle, this project explores the evolution and expression of parental care in humans using life history, parental investment, and parent-offspring conflict theory. The project combines empirical (ethnographic and experimental) and theoretical (optimality modeling) approaches. The project has been funded by the Andrew W. Mellon Foundation, the National Science Foundation, and the National Institutes of Health. The project also includes a collaborative and open-access component, the Parental Investment Vignette Project. Results have been published in Royal Society Open Science, PLoS One, Human Nature, American Journal of Human Biology, and the Journal of Biosocial Science.

Culture, Biology, and Human Mating

This project explores the role of biology and culture in shaping human mating preferences and behaviour. The project includes both empirical (ethnographic and experimental) and theoretical (game theory modeling) perspectives. Results have been published in Human Nature and Evolution and Human Behavior.

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Wedding of Karo impal couple

It also includes collaborative work with Dan Fessler (UCLA, Anthropology). We are testing various evolutionary and non-evolutionary hypotheses to explain the low rate and apparent decline of matrilateral cross-cousin (impal) marriage among the Karo people of North Sumatra, Indonesia. The project includes archival work using marriage and baptism records from 1940 onward collected in Kabanjahe in 2010, and ethnographic work from 2014 that includes detailed interviews with the husband and/or wife from 114 impal and 119 non-impal marriages conducted in over 50 villages. The project is funded by: (a) UCLA’s Center for Culture, Brain, and Development; (b) the American Institute for Indonesian Studies (AIFIS); and, (c) the Fulbright Scholars Program. The first publication from this project appeared in Current Anthropology, and we have another paper in press at Human Nature. I kept a blog of my fieldwork experience for this project.

Land Tenure and Subsistence


Buffalo cart (North Sumatra, 2004)

This is a collaborative research project that uses evolutionary and statistical methods to reconstruct the evolution and explain the current distribution of land tenure and subsistence norms in societies around the world. My involvement with this project began with an analysis of land tenure norms in Austronesian societies in collaboration with Fiona Jordan (Anthropology, University of Bristol) and Russell Gray (Psychology, University of Auckland). In our 2014 Evolution and Human Behavior paper, we showed that land tenure norms evolved along a linear trajectory among other things. We hypothesized that population pressure and the dynamics of expansion might explain this pattern. In 2015, I worked on a phylogenetic analysis of land tenure norms on deforestation in Austronesian societies in collaboration with Quentin Atkinson (Psychology, University of Auckland) and Simon Greenhill (Linguistics, ANU). In 2015, a research group that I belong to as a Research Scientist won a 1 million USD National Science Foundation grant to study the Geography and Evolution of Land Tenure and Subsistence (GELTS) in all of the major language groups around the world. This project is a collaboration between: Mike Gavin (Natural Resources, Colorado State University); Claire Bowern (Linguistics, Yale University); Bobbi Low (Natural Resources, University of Michigan); Carlos Botero (Biology, Washington University); Fiona Jordan; Russell Gray; and, Carol Ember (HRAF, Yale University).

Culture and the Mind


Interview (North Sumatra, 2011)

The “Culture and the Mind” Project is a major collaborative project funded by the UK’s Arts and Humanities Research Council to test evolutionary hypotheses about moral and property-related cognition cross-culturally. I was brought on for Phases II & III. My participation in the project included three workshops, one at University of Sheffield and one at UCLA, two summers of fieldwork in Indonesia, and ongoing analyses and manuscript preparation. The collaborators on this project include anthropologists, psychologists, and philosophers from around the world. The project leads are: Stephen Laurence (Philosophy, University of Sheffield); Dan Fessler (Anthropology, UCLA); Clark Barrett (Anthropology, UCLA); and, Joe Henrich (Human Evolutionary Biology, Harvard).

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Click here for my official ANU Researcher website.