Across undergraduate STEM learning contexts in several countries, students' intrapersonal attributes of epistemic beliefs, self-efficacy beliefs, intrinsic motivation, and sense of identity have been found to influence learning and to change in response to educational practices. However, research can mask individual and demographic differences in student's attributes that may moderate or mediate the relationship between educational practices and learning outcomes. We employed variable-centered and person-centered methods to examine individual and demographic differences in changes in students' intrapersonal attributes and patterns of interrelationship among attributes with a study sample of students (N = 4,500) in 14 STEM undergraduate courses (8 biology, 4 chemistry, and 2 statistics) at three research universities in the United States. Variable-centered analyses revealed overall increases in students' science self-efficacy beliefs and epistemic beliefs even though these outcomes were not intentionally targeted as learning objectives. However, person-centered analyses indicated that not all students experienced these gains. For example, self-identified Asian/Pacific Islander and Black students were more likely to be members of groups demonstrating a decrease in science self-efficacy, whereas Asian/Pacific Islander students and men were less likely to be members of the subgroup with consistently evaluativist epistemic beliefs and higher GPAs. Using latent profile analysis (LPA), we identified five distinct student profiles that reflected different patterns of interrelationship of epistemic beliefs, science and writing self-efficacy beliefs, and science identity. We discuss the implications of these findings for educational practices, particularly with regard to intentionally fostering diverse students' self-efficacy, sense of identity, and adaptive epistemic beliefs.