Contemporary theoretical tools in the social sciences and humanities hinder an understanding of the dynamic interplay between reflexivity and routine in the formation of sex, gender, and sexual identities. In A Kaleidoscope of Identities, James W. Messerschmidt and Tristan Bridges build on the work of feminist sociologists in examining the relationship among situational interaction, accountability, and relational and discursive social structures to uniquely conceptualize sex, gender, and sexual practice as both reflexive and routine. Drawing on nuanced and powerful life-history interviews, Messerschmidt and Bridges present a new theoretical framework situating reflexivity and routine in a much more symbiotic relationship than has been previously acknowledged. Without privileging either, Messerschmidt and Bridges explore this relationship through a novel analysis of the ways reflexivity and routine collaboratively shape sex, gender, and sexual identities over time and across space. A Kaleidoscope of Identities provides a fresh, accessible, and provocative argument advancing our knowledge on the changing nature of sex, gender, and sexual identity formations alongside transforming systems of power and inequality.