Date of Award


Degree Type


Degree Name

Doctor of Philosophy (PhD)




Affective polarization, the phenomenon of liberals and conservatives treating each other as disliked outgroups, is increasingly intense (Iyengar & Westwood, 2015; Pew, 2016). In the present research, I used the construct of psychological essentialism (Medin & Ortony, 1989) to help understand this intergroup phenomenon. Specifically, I measured political essentialism, or the belief that political ideologies are strongly determined, informative, discrete and/or immutable, and tested the relationship between these beliefs and affective polarization. I approached this question with both correlational and experimental methods. In a correlational study, political essentialism overall is found to covary positively with affective polarization and social avoidance of political outgroups. Essentialism is found to be most predictive when treated as a collection of distinct lay beliefs, rather than a unitary construct. Informativeness and discreteness beliefs correspond strongly and positively with affective polarization, while biological basis beliefs and social deterministic beliefs have weak effects in the opposite direction. In the experimental study, manipulating essentialism beliefs had no effect on affective polarization or desire for social distance. Potential reasons for the discrepant results are explored. In sum, this research supports the hypothesis that political essentialism is associated with affective polarization, but does not provide evidence that essentialism plays a causal role in this relationship.

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.