The line between gender and sex has become increasingly muddled in literature. Tensions surrounding this topic are ever-increasing and definitions of the two are rarely consistent. For improving conceptual clarity, we adopted the Social Role Theory to explore how these two terms differ and relate by laying out a cyclical framework of biological, sociological, and psychological components. Herein, we discuss the origins of the binary sex construct, anatomical brain/cognition differences, and sex/gender role implications for education and physical education. We confront the topic in a content area that continues to be masculine-oriented with the purpose to conceptualize sex/gender in physical education research through clarifying the evolutionary biosocial spectrum. Offering a reconceptualization of gender as a multidimensional construct could inspire further curricular reform for the content to be more inclusive of all participants, learnable by all students regardless of sex and gender, and beneficial both mentally and physically to all learners.