Distinguishing stable from changing components of psychological similarity in undergraduates’ mentoring relationships over time

Mentorship promotes undergraduate student success and integration into STEM fields. The strongest and most consistent predictor of high-quality mentoring is perceived psychological similarity (e.g., shared attitudes) between mentees and their mentors, yet little is known about how these perceptions develop over time. Using longitudinal data and latent state-trait modeling, we examined how undergraduate mentees' perceived psychological similarity and the mentoring support they received from their faculty mentors influence one another. Most of the variance in psychological similarity reflected stable, trait-like tendencies, whereas a smaller portion of the variation was due to occasion-specific fluctuations. By contrast, most of the variance in mentoring support was state-like, due to occasion-specific fluctuations. Cross-lagged panel analyses revealed that early increases in psychological similarity predicted later perceptions of mentor support within the same academic year, whereas earlier mentor support consistently predicted future psychological similarity, both within and across academic years. These results suggest bidirectional, though asymmetric, temporal associations between psychological similarity and mentoring support. Undergraduates’ momentary beliefs that their mentor was a role model were associated with greater mentorship support, independent of their feelings of psychological similarity. These findings highlight the importance of longitudinal methods for capturing the dynamic, time-sensitive nature of mentoring relationships.