Robert Gruber, Michael Häfner, Sven Kachel

• Clothing behaviour remains an understudied research area within social psychology. Through the present research, we aim to anchor attire as an empirical research subject by investigating the psychological properties of one of its functionalities, namely, to provide protection. We argue that attire's undisputed role in shielding humans from environmental hazards may extend to the psychological level and protect them from the incorporeal consequences of existential threats symbolically. In this Registered Report, a mixed-methods approach links an ecologically valid field study of self-presentation in social media posts during Russia's war on Ukraine (Study 1; N = 248) with supraliminal priming of mortality salience in an online experiment (Study 2; N = 248). Across both studies, we expect that mortality concerns let people accentuate the physically protective attributes of clothing (e.g. more layers of clothing) and resort to more in-group prototypical dress styles (i.e. more gender-stereotypical). Findings show that people adjust their clothing preferences in response to existential threats, favouring in-group prototypical clothing (more gender-typical for both women and men in Study 1) and physically protective attire (higher in women and lower in men in Study 2) during high (vs. low) levels of existential threat. By positioning clothing as a research area within social psychology, our goal is to stimulate a wave of research on its profound role for humankind. Furthermore, we provide a dynamic and robust methodological approach to researching terror management theory.