Hormonal Contraceptive Use and Cycle Phase Effects on Competitive Persistence: Progesterone as a Mediating Mechanism (Stage 1 Registered Report)

Abstract

Objectives: Increasing evidence suggests that hormonal contraceptive (HC) use adversely effects psychological functioning and competitiveness. HCs expose women to consistently high doses of synthetic progesterone, a hormone that fluctuates across the natural menstrual cycle. We propose to test group differences in competitive persistence between HC users, naturally cycling (NC) women in their low progesterone phase, and NC women in their high progesterone phase. Additionally, we will test salivary progesterone among NC women as a mediator of phase effects on competitiveness.Method: Pre-screening will identify HC users, and naturally cycling women at the two cycle phases. Participants will provide a sample of saliva and complete two behavioral competitiveness tasks. Covariates will also be collected.Predicted Results: We predict that follicular phase NC women will demonstrate longer competitive persistence compared to luteal phase NC women and HC users. Progesterone will positively mediate the effect of cycle phase on competitive persistence among NC women. Conclusions: This research will address the effects of HC use, cycle phase, and progesterone levels on competitive behavior in women. The outcome may be an artifact of female reproductive physiology that is likely adaptive, but potentially detrimental to women’s social and occupational advancement, raising concerns about the social-psychological risks of HC use.