Researcher in Cultural Evolution
Senior Lecturer in Applied Mathematics
I study human behaviour and its effects on society through mathematics, experiments and simulations. I am currently focusing on issues related to interrelationships between cultural traits, group formation, homophily, segregation and norm change, 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 learned behaviour. Culture is subject to an evolutionary process: there is variation, it is replicated between individuals and cultural traits have different rates of survival. I have studied the spread of popular traits through turnover rates on toplists, the emergence of Creole languages, and democratic transitions.
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. 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. We use formal modelling to describe cultural systems and agent-based simulations to illustrate the usefulness of this approach for identifying and explaining important properties of cultural evolution and selection biases.
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 am currently conducting 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.
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.