My research focuses on using innovative quantitative research methods to study human cultural evolution. I have two main topics of research; mentalising and religion.


Colexification of emotion concepts across languages

People have an exceptional capacity to infer mental states such as beliefs, emotions, intentions, and desires. This capacity, known as mentalising or theory of mind, is widely regarded as providing the foundations of human social learning, empathy, cooperation, and communication.

I study how cultural and biological processes interact to shape the way people think about, express and communicate mental states. I am currently leading the construction of a database of mental state vocabulary named LexiCog. Leveraging LexiCog and new methods of language analysis, my research investigates cross-cultural structure and variation in mentalising practices.

Examples of research outputs:

Jackson, J. C., Lindquist, K., Drabble, R., Atkinson, Q., & Watts, J. (2022). Valence-Dependent Mutation in Lexical Evolution. Nature Human Behavior, 7, 190-199.

Jackson, J.C., Watts, J., Henry, T.R., List, J.M., Forkel, R., Mucha, P.J., Greenhill, S.J., Gray, R.D., & Lindquist, K.A. (2019). Emotion semantics show both cultural variation and universal structure. Science, 366(6472), 1517-1522.

Low, J., & Watts, J. (2013). Attributing false-beliefs about object identity is a signature blindspot in humans' efficient mind-reading system. Psychological Science, 24(3), 305-311.


Religious systems show variation between groups, they are transmitted and modified over generations, and they differ in their ability to gain and retain members. In other words, religions show the key properties of an evolutionary system. The evolution of religion provides ideal subject matter for building and testing theories about the evolutionary dynamics of human culture, cognition and behaviour.

I specialise in building large-scale cross-cultural databases and using phylogenetic comparative methods to model cultural macroevolution. I led the construction of the Pulotu database of Pacific religions and the Hunter-gatherer Religion Database. These are quantitative, cross-cultural databases built from ethnographic records. By combining these databases with newly developed phylogenetic comparative methods I have tested high profile hypotheses about how supernatural beliefs co-evolve with socio-political structures.

Examples of research outputs:

Watts, J., Hamerslag, E.M., Sprules, C., Shaver, J.H., & Dunbar, R.I.M. (2022). Food storage facilitates professional religious specialization in hunter-gatherer societies. Evolutionary Human Sciences, 4, E17.

Watts, J., Sheehan, O., Bulbulia, J., Gray, R.D., & Atkinson, Q.D. (2018). Christianity spread faster in small politically structured societies. Nature Human Behaviour, 2, 559-564.

Watts, J., Sheehan, O., Atkinson, Q.D., Bulbulia, J., & Gray, R.D. (2016). Ritual human sacrifice promoted and sustained the evolution of stratified societies. Nature, 532 (7598), 228-231.

Examples of media coverage:

The Times. Power not poverty spreads Christianity, study finds. Tom Whipple.

Science. Human sacrifice may have helped societies become more complex. Emily Benson.

International Business Times. Belief in supernatural punishment not ‘big gods’ gave rise to complex societies. Hannah Osborne.