<p>  </p> <p>The engineering education community in the United States has witnessed a tremendous increase in broadening participation initiatives as they wrestle with issues regarding inclusion. To date, these initiatives have targeted several goals, including access, belonging, and retention of students from underrepresented backgrounds. However, these initiatives have generally focused on the experiences of individual students, while systemic barriers, such as the cultural ideologies sustaining a "chilly climate" of engineering, have received less attention.</p> <p>Engineering instructors play a critical role in maintaining the professional culture of engineering through the socialization of undergraduate engineers embedded in the requirements of degree attainment. As engineering students transition through the plan of study, they are socialized to knowledge, skills, and values deemed necessary by instructors and administrators for entry into the engineering profession. The knowledge, skills, and values reinforced by instructors across the socialization process become taken-for-granted as cultural norms reproduced through engineering courses. As a result of these cultural reproductions, engineering instructors shape the boundaries of what it means to be an engineer. The study aimed to investigate how instructor's agency plays a role in establishing cultural norms in their undergraduate engineering courses. Furthermore, the study examined how these norms subsequently influence engineering students' perceptions of the professional culture of engineering. The goal was to understand the mechanisms that maintain and replicate cultural norms in engineering's "chilly climate" and engineering students' perceptions of inclusion (or lack thereof). </p> <p><br></p> <p>This dissertation employed an ethnographic case study approach to investigate the following research questions: (1) What culture did engineering instructors (re)produce in their undergraduate engineering courses?; (2) How were engineering instructors' cultural (re)productions communicated to undergraduate engineering students in their courses?; and (3) How did engineering instructors' agency (or lack thereof) influence their (re)production of ideologies in the professional engineering culture? The research questions examined how instructors' cultural (re)productions in engineering shape the professional culture of engineering. The study included an analysis of instructors' interviews, my classroom observations, course documents, and student focus groups for two sequential mechanical engineering courses in the plan of study.</p> <p><br></p> <p>The engineering instructors expressed agency as the three dimensions referred by Emirbayer and Mische (1998) of "chordal triad" (p. 970)—iterational, projective, and practical-evaluative. As the instructors negotiated their agency through their perspectives and actions, they exhibited the iterational through invocations of their experiences, the projective through their course intentions, and the practical-evaluative in their teaching practices and content. In these cases, I identified four cultural ideologies currently at the foundation of the engineering courses: technocratic, depoliticization, meritocratic, and care. Instructors' experiences, departmental priorities, and teaching practices all played a role in the prevalence of a technocratic culture. Omitting sociopolitical considerations perpetuated a depoliticized environment, while instructors showed a dual agentic orientation by navigating between meritocratic values and care for students. The COVID-19 pandemic emphasized the importance of critical policy and advocacy, instructor empathy, and individual actions in driving collective momentum for transformative social change in engineering settings. A conscientious understanding of the impact of our actions as instructors on the socialization of engineering students is essential. This understanding needs to take up both individual's agency and the context in which agency is enacted to create a space in the profession that authentically reflects and embraces differences among students as integral members of the profession. The research findings serve as an invitation for growth for the engineering education community to "walk the walk". An invitation to be courageous leaders, who try, test, and refine our practices through critical reflections, aligned intentions and agentic actions that engage and support all engineering students, especially students from historically marginalized communities.</p>