Abstract: Why do women remain underrepresented in some STEM fields? Frequently explored possibilities include gender differences in socialization, historical patterns of discrimination, and hostile climates of harassment. Recent research in social psychology has explored the effects of contextual variables such as belongingness cues. Yet another potential contributing factor is the experience of Sensitivity about being the Target of a Threatening Upward Comparison (STTUC; Exline & Lobel, 1999). STTUC is the discomfort that individuals may feel when they succeed while sensing that their success upsets others. Such discomfort may co-exist with the positive affective consequences that typically accompany success. Three conditions lead to the experience of STTUC: 1) perceiving oneself as an upward comparison target, 2) perceiving the outperformed person as upset about being outperformed, and 3) being concerned about oneself, the other person, and/or their relationship. STTUC has interesting implications for Interpersonal Theory, as it may pit goals of agency (e.g., to succeed) and communion (e.g., to connect) against each other. Consistent with this possibility, research reveals that STTUC-related distress correlates positively with sociotropy (i.e., a communal trait involving excessive concern with people-pleasing), whereas positive emotion in response to outperforming others correlates positively with narcissism (an agentic trait; Exline & Zell, 2012). In this review, I delineate why women in STEM might be especially likely to experience STTUC in their chosen fields. I then explore possible consequences of STTUC and conclude with some strategies that might lessen the likelihood of STTUC among women in STEM. __________________________________ Erika Koch, Ph.D.