Hormonal contraceptive use, not menstrual cycle phase, is associated with reduced interest in competition

Despite numerous studies attempting to understand the influence of fertility and hormonal contraceptives on competitive outcomes, the association between these variables remain a contentious issue. Using a longitudinal, online diary study with over 5600 daily observations (N = 302 community and undergraduate student participants), we explored the effects of fertility probability and hormonal contraceptive use on a range of self-report competitive outcomes. Specifically, we sought to replicate existing findings by examining whether self-reported competitive motivation increases mid-cycle and how hormonal contraceptive use affects these patterns. We also sought to extend this literature by collecting a range of self-report measures of competitive behavior across the menstrual cycle. Using an evolutionary and data-driven framework, we combined six behaviors females use to compete for mates and status: gossip, social comparison, negative evaluations of others, appearance enhancement, giving advice and taking sexy self-portraits. Contrary to our predictions, fertility probability was not associated with fluctuations in self-reported competitive motivation or behavior. However, replicating existing literature, hormonal contraceptive users reported a general lack of interest in competition compared to non-users. This latter finding raises important questions about the long-term implications of hormonal contraceptive use and suggests a need for further research to investigate the psychosocial effects of hormonal contraceptives. Finally, as a near direct replication of an existing longitudinal study, the current research offers a unique contribution by considering the role of context in hormone mediated research. We question the idea that a failure to replicate reflects the quality of the theory or the research, but instead suggest that context should be considered when developing psychological theory.