UCLA

Most women in the United States use hormonal contraceptives at some point in their lives, yet little is known about their psychological side-effects. A number of scholars have recently argued that hormonal contraceptives might impair women's ability to choose desirable mates and cause problems in their relationship functioning. My dissertation evaluated these claims through a comprehensive review of the literature and two empirical studies. In my review of more than 30 studies examining associations between hormonal contraceptive use and variables related to mate choice and relationship functioning, I found modest support for hypotheses about the effects of hormonal contraceptive use. The most robust finding was that, unsurprisingly, hormonal contraceptive users did not experience cycle shifts in mate preferences and attractiveness that had been identified in previous research (e.g. Gildersleeve, Haselton, & Fales, 2014). I note a general weakness in the literature - none of the studies comparing hormonal contraceptive users to non-users employed experimental methods, precluding causal conclusions about the effects of hormonal contraceptives. I also report two empirical studies. In the first, I tested one particular hypothesis regarding negative effects of hormonal contraceptive use. Partners who are similar to one another in their Major Histocompatibility Complex (MHC) genes are thought to be relatively less genetically compatible than partners who are dissimilar in their MHC genes. Researchers have hypothesized that hormonal contraceptives disrupt MHC preferences. I examined whether hormonal contraceptive users are indeed more MHC-similar to their partners than non-users. Both members of 274 couples were genotyped at the MHC region; the female partner reported her hormonal contraceptive use at the time the relationship began. Contrary to predictions, I found that women who used hormonal contraceptives when they met their partner were more MHC dissimilar to their partners than non-users, although this difference was not statistically significant. Additional analyses involving many potential confounds that might be masking a true relationship did not produce the predicted effect. The results of this study are inconsistent with the hypothesis that hormonal contraceptives will cause women to choose MHC similar, and thus genetically incompatible, romantic partners. In the second study, I addressed the hypothesis that cycle shifts previously documented among naturally cycling women (reviewed in Larson, Pillsworth, & Haselton, 2012) would be absent among hormonal contraceptive users. To test this hypothesis, I recruited a sample of 56 women to complete nightly surveys assessing their current attractions toward their romantic partner and toward men other than their partner (for a total of 1,366 observations). Consistent with the hypothesis, I found that cycle shifts in attraction to other men observed among non-users were absent among hormonal contraceptive users. The results of this study therefore demonstrated a potential relationship-protective effect of hormonal contraceptive use. Overall, the results of my dissertation indicate that although hormonal contraceptive users and non-users do differ in some important ways, the differences are not as large, global, or negative as previous researchers have implied.