Abstract
Gender categorization is central to everyday life. Discussions about gender have traditionally focused on gender identities, or gender categories to which a person might have an internal sense of belonging (e.g., men and women, boys and girls). More recently, discussions about gender also include gender modality (transgender or cisgender), or how a person's gender identity relates to their sex assigned at birth. In this registered report, we investigate gender-relevant categorization including gender identity and gender modality using measures assessing the automatic encoding of categories and explicit beliefs about the similarity between categories. We also compare performance on these tasks in transgender and cisgender youth and adults to help shed light on long-standing debates about the role of experience in categorization. Across two studies (N = 1144), we found that participants automatically encoded both gender identity and gender modality, and that variations in categorization between participant groups were largely mediated by participants' attitudes (i.e., openness to nonbinary identities) and experiences (i.e., contact with trans people). These results thus help refine our psychological theories of gender categorization to more accurately reflect the landscape of gender categories permeating modern society.