The Hot Politics Lab has contributed to the conceptual development of populism, and an understanding of its psychological roots. In, for example, this paper Matthijs Rooduijn contributes to the conceptual development of populism, as well as setting a future research agenda. In joint work we find that the personality trait Agreeableness predicts populist voting. Across countries, and different left-wing or right-wing populist parties, we find that low Agreeable individuals are more likely to support populists. Using a survey experiment we find that in particular anti-establishment rhetoric links Agreeableness to populist voting. 

Bert N. Bakker, Jaidka, K., Dorr, T., Fasching, N., & Lelkes, Y. (accepted for publication). Questionable and open research practices among quantitative communication researchers . Journal of Communication.
Bert Bakker, Gijs Schumacher & Matthijs Rooduijn (2021). The populist appeal. Personality and anti-establishment communication. The Journal of Politics, 83(2), 589-601.
Matthijs Rooduijn (2019) How to study populism and adjacent topics? A plea for both more and less focus . European Journal of Political Research.
Bert Bakker, Matthijs Rooduijn, & Gijs Schumacher (2016). The Psychological Roots of Populist Voting: Evidence from the United States, the Netherlands and Germany. European Journal of Political Research.
Gijs Schumacher & Matthijs Rooduijn (2013). Sympathy for the 'Devil'? Voting for Populists in the 2006 and 2010 Dutch General Elections. , Electoral Studies.