There have been significant strides towards diversifying STEM majors to include more students of color and women. With current and anticipated future technological advances, the United States must prepare as many students as possible to become leaders in STEM fields. Despite significant strides, women of color, specifically Black and Latina women, represent the smallest percentage of students in STEM, and are not liking to stay within their STEM fields for more than 15 years after graduation. To improve the graduation rates of these demographics, higher education institutions must find new ways with existing resources to best support these student groups. This study explored the role of faculty members who participate in Organizational Citizenship Behavior (OCB), in the form of student mentorship. Investigating OCB among some STEM faculty members identified ways higher education institutions can encourage additional STEM faculty members to use their time for student mentorship, especially for students from marginalized communities, such as Black and Latina women in STEM. The study also explored what it would look like if mentorship was expected of all faculty members, instead of relying on OCB from a select few. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]