Matthew Gwynfryn Thomas

My anthropology research uses evolutionary theory to look at how people cooperate (or not) in households, families and larger groups.

I did my PhD (titled 'The Dynamics of Human Cooperative Groups') in the Human Evolutionary Ecology Group at UCL in London. You can read it here. Afterwards, I worked as a postdoc for the Norwegian Institute for Cultural Heritage Research (NIKU) and the Norwegian Institute for Nature Research (NINA), as part of the project, "ReiGN: Reindeer husbandry in a Globalizing North".

Here's a haiku summary of my research:

People sometimes help
friends, fam, neighbours, not witches.
But sometimes they don't.

... and a summary written using only the ten hundred most common English words:

We think we know what people are like from how they act in rooms where brain-people in white jackets make them do things. But I want to check how people act in real life. I looked at how people work together in two places - one where they keep animals in the cold land at the top of the world and another place where they grow food around a body of water in a big big land. The people helped their friends, family and other close people. They liked good people and didn't help bad people.

I used a mixture of theoretical models and actual, real-life fieldwork to understand patterns of cooperation.

For the theoretical bit, I made mathematical models and computer simulations of evolutionary dynamics to look at how mortality in the environment and competition between siblings shape birth patterns (published in the Journal of Evolutionary Biology).

For the empirical bit, I worked with Saami reindeer herders in the county of Finnmark, Norway. I used experimental economic games and statistics to understand how Saami people worked together in herding groups. I've also looked at how kinship, reputation and reciprocity affect how Mosuo farmers work together in southwestern China.

You can academically socialise with me on ResearchGate, or Google Scholar.


Page A E, Thomas M G, Smith D, Dyble M, Viguier S, Chaudhary N, Salali G D, Thompson J, Mace R, Migliano A B. (2019). Testing adaptive hypotheses of alloparenting in Agta foragers. Nature Human Behaviour. [paper] [code]

Du J, Thomas M G, Bårdsen B-J, Mace R, Næss M W. (2019). Comparison of social complexity in two independent pastoralist societies. Behavioral Ecology and Sociobiology. [paper] [data + code]

Thomas M G, Ji T, Wu J, He Q, Tao Y, Mace R. (2018). Kinship underlies costly cooperation in Mosuo villages. Royal Society Open Science. [paper] [data] [code]

Thomas M G, Bårdsen B-J, Næss M W. (2018). The narrow gap between norms and cooperative behaviour in a reindeer herding community. Royal Society Open Science. [paper] [data] [code]

Mace R, Thomas M G, Wu J, He Q, Ji T, Tao Y. (2018). Population structured by witchcraft beliefs. Nature Human Behaviour. [paper] [code]

Thomas M G, Næss M W, Bårdsen B-J, Mace R. (2016). Smaller Saami herding groups cooperate more in a public goods experiment. Human Ecology. [paper] [data + code] [summary]

Thomas M G, Næss M W, Bårdsen B-J, Mace R. (2015). Saami reindeer herders cooperate with social group members and genetic kin. Behavioral Ecology. [paper] [data] [code] [summary]

Thomas M G, Shanley D P, Houston A I, McNamara J M, Mace R, Kirkwood T B L. (2015). A dynamic framework for the study of optimal birth intervals reveals the importance of sibling competition and mortality risks. Journal of Evolutionary Biology. [paper] [data] [source code] [analysis code] [summary]