This study is part of a larger research that explores the creation of an instrument to capture the social and cultural factors that affect Black students' persistence in STEM. Most research on self-efficacy in the science education literature were either done at predominantly White institutions, during summer programs for students of color, or on predominantly White populations. This study provides insights into self-efficacy indicators at an institution that was specifically created to consider the social, cultural, and historical implications for educating Blacks in STEM. One hundred sixty-four undergraduate students enrolled in an introductory biology course at an Historically Black College and University completed a questionnaire. The survey addressed the hypothesized factors--expectancy, self-efficacy, familial self-efficacy, cognitive self-efficacy, and commitment. The results highlight the importance of science identity and familial sources of vicarious experiences as important indicators of persistence and performance in STEM. The importance of social and cultural factors for Black students' persistence in STEM is underscored.