Dr. Brendan Barrett

I am an evolutionary behavioral ecologist interested in how extragenetic inheritance systems such as culture and territorial inheritance are influenced by (and in turn influence) ecology, sociality, and life history. My research uses a combination of field observation and experimentation, hierarchical Bayesian statistical modelling, and game-theoretical and population modelling. Some of my ongoing research questions include:

1. What predicts individual variation in social learning strategies and how does individual behavior shape population-level cultural dynamics?
2. How does sociality and ecology influence both the origins and maintenance of cultural traits in populations?
3. What social and ecological factors predict territorial bequeathal and dispersal?
4. How is social learning utilized by organisms across different life history stages?
5. How do organisms integrate both personal and social information and what are the implications of this for structuring cultural variation and dynamics?

Bequeathal in dusky footed woodrats (Neotoma fuscipes).

My work with woodrats, conducted with MPIO’s Mary Brooke McElreath, looks at bequeathal—a poorly understood form of breeding dispersal where juveniles inherit the natal territory and parents disperse. While woodrats often bequeath their territory to their offspring, this is not always the case-- juveniles may also disperse. To understand bequeathal, we are testing predictions from a game theoretical model we developed to see the conditions under which bequeathal would be favored by natural selection. Since 2011, we have been collecting data on woodrat relatedness, population density, movement ecology, and territory quality at the Quail Ridge Biological Reserve in Napa County, California, USA.

Cultural transmission and innovation in white-faced capuchin monkeys (Cebus capucinus)

I recently started a fieldsite in Coiba National Park, Panama looking at extractive foraging innovation, cultural transmission of tool use, genetic uniqueness  and dispersal ecology in capuchins with Meg Crofoot of UC Davis. I also work with Susan Perry of UCLA to analyze long-term data collected on capuchin social learning and behavior at Reserva Biological Lomas Barbudal, Costa Rica. My dissertation work at Lomas examined the dynamics of cultural transmission of extractive foraging behaviors and understanding what properties of individuals predict the origins and transmission of innovations across behavioral domains.

Statistical methods and theoretical modeling of cultural transmission

I am also interested in developing and communicating dynamic, hierarchical statistical modeling techniques for examining social learning data-- and behavioral data more generally. This includes dealing with multinomial data, correlations between behaviors, using multiple learning strategies simultaneously, and individual variation in the integration of personal and social information. My goal is to link analytical techniques more closely to the theoretical models we use to inform our predictions in behavioral ecology and cultural evolution. This work is primarily done using Hamiltonian MCMC (r-STAN). All of my code, simulations, and data (when possible) are openly shared on my GitHub account. Ongoing theoretical modeling projects look at gene-culture coevolution in stage structured populations, interactions between frequency dependent learning and individual learning, and social learning in rapidly changing environments. The quantitative components of my research are conducted with MPIO’s Lucy Aplin, Mary Brooke McElreath and Richard McElreath at MPI-Evolutionary Anthropology in Leipzig.