Associate Professor in Applied Mathematics
Researcher in Cultural Evolution
I study human behaviour and its relation to societal phenomena through mathematical modelling, experiments and simulations. My work is highly interdisciplinary, and I often tap into psychology, sociology and philosophy, and have co-authored papers with colleagues from biology, linguistics and political science. I am currently focusing on issues related to systemic properties of cultural evolution, norm change, spread of (dis)information, polarisation, group phenomena, AI, and am generally interested in issues related to cultural evolution.
I am interested in the mechanisms that shape and change human culture, broadly defined as socially transmitted information. Cultural evolution refers to the process through which cultural traits, ideas, practices, and behaviours change over time. It has some similarities to biological evolution: there is variation, it is replicated between individuals and cultural traits have different rates of survival. At the same time, many processes are different, so we need to come up with new mathematical models to explain and predict cultural evolution, taking in theory from the humanities and social sciences.
Many phenomena in cultural evolution cannot be explained unless we consider the interdependence between traits. For example, traits vary in compatibility, which should influence their transmission. The belief in Shiva is harder to spread if potential recipients already believe in a monotheistic god. Culture is embedded in culture, and the interactions between cultural traits and how we process these give rise to complex patterns, such as path dependence, historical traces and long periods of stability with rapid leaps, and phenomena, such as experience-guided learning, polarisation and filter bubbles. Structural dependencies have the consequence that existing traits influence the acquisition of new traits, and can even provide a mechanistic explanation to the transmission process itself.
AI and society
In a large research project over the coming years, we will study how digital information technologies, such as social media and artificial intelligence, influence cultural evolution and the consequences for society, with a focus on knowledge and disinformation, polarisation and segregation, and social influence and trust. Previous technology such as book printing and calculators have had a vast influence on cultural evolution, but what we see now may be a paradigmatic shift, where technology reduces the importance of geography, and where artificial intelligence processes information for us in unpredictable ways.
Groups and cooperation
Group membership may be defined through ethnicity, common language, shared preferences or any aggregation of people with some defining characteristics, and leads to widespread phenomena such as ingroup favouritism and polarisation of opinions and attitudes. Previous experiments have shown that these effects can be triggered by even completely arbitrary distinctions between groups. Through game theory and behavioural experiments, I have studied what are possible mechanisms behind group discrimination, and what means there are to increase cooperation between groups.
Groups tend to cluster in society, such that people of similar background end up going to the same schools, workplaces and live in certain neighbourhoods, separated from other groups, with the result of reproducing social inequalities. I have worked on inferring propensities for social ties among immigrants in school based on data on educational choices; simulating residential segregation; surveying people’s attitudes towards ethnically diverse workplaces; and investigated how segregation and polarisation can be mutually reinforcing through social influence.
Norm change and moral values
I have conducted experiments on how changes in norms and attitudes can be predicted from the moral foundations of individuals. Previous research on moral foundations has shown that moral judgements are generally based on a limited number of categories. While individuals vary in which categories are important to them, some of these categories are important to almost everyone, and thus seem to drive moral norm change in society. This serves as a concrete example of how systemic properties of culture can predict the direction of change.
Using data on political institutions, I have examined general patterns for democratic transitions, and was recently involved in a large project on identifying sequences of democratisation processes.