This position paper explores the intricate relationship between social psychology and secure software engineering, underscoring the vital role social psychology plays in the realm of engineering secure software systems. Beyond a mere technical endeavor, this paper contends that understanding and integrating social psychology principles into software processes are imperative for establishing robust and secure software systems. Recent studies in related fields show the importance of understanding the social psychology of other security domains. Finally, we identify critical gaps in software security research and present a set of research questions for incorporating more social psychology into software security research.