Hormonal birth control (HBC) introduces synthetic hormones, typically progestin and a synthetic estrogen, into the body to prevent pregnancy. These hormones primarily suppress ovulation but also influence various biological processes. Attraction and partner choice are complex processes influenced by a person’s underlying hormonal state. By altering the natural hormonal balance to mimic pregnancy, HBC may interfere with the subtle biological cues governing mate selection. This interference can shift what an individual finds attractive and how attractive they are perceived by others.
The Hormonal Basis of Attraction
The natural menstrual cycle involves fluctuating reproductive hormones that influence mate preferences. During the high-fertility phase, culminating in ovulation, estrogen peaks significantly. This surge is associated with a temporary shift toward partners displaying markers of high genetic quality. Studies show women near ovulation often prefer men with highly masculine facial features and deeper voices. This preference is theorized to be an evolved mechanism seeking mates with robust immune systems, potentially leading to offspring with stronger genetic fitness. HBC maintains steady, low levels of synthetic hormones, suppressing the natural cycle’s fluctuations and preventing the estrogen peak. Consequently, HBC dampens the hormonal signals that drive the temporary attraction to highly masculine traits, keeping the body in a state that mirrors the low-fertility phase.
How Hormonal Contraceptives Alter Partner Preference
HBC use shifts the qualities a woman finds appealing, moving away from traits associated with genetic fitness. A key area of study is the Major Histocompatibility Complex (MHC), a set of genes related to immune function detectable through body odor. Naturally cycling women prefer the scent of men with dissimilar MHC profiles, promoting genetic diversity in offspring. However, women taking HBC often show a reversed preference, leaning toward the scent of men with more genetically similar MHC profiles. This shift is hypothesized to be a side effect of the pseudo-pregnant state, where prioritizing proximity to kin for social support may override seeking genetically diverse mates. Furthermore, the preference for highly masculine facial features is often reduced in women on HBC. Studies indicate a preference for men with more feminized or less dominant features. This suggests an attraction toward men who signal cooperative and parental investment qualities, sometimes called “good dad” traits, over purely genetic ones.
Impact on Attractiveness Cues Perceived by Others
Hormonal status affects the subtle cues women emit, signaling their reproductive state to potential partners. The natural rise in estrogen during the fertile window enhances outward signs of attractiveness, including changes in vocal pitch and scent, which communicate peak fertility. HBC suppresses these outward fertility signals because the hormonal environment remains artificially stable. For example, vocal attractiveness increases in naturally cycling women approaching ovulation, but this effect is absent in those using hormonal contraception. A field study involving professional dancers found that naturally cycling women earned significantly more tips during their fertile window, an income boost not observed among those taking HBC. These findings suggest that the steady hormonal environment created by HBC dampens the subtle cues men unconsciously perceive as indicators of high fertility, potentially altering how attractive a woman is perceived.
Post-Pill Shifts in Relationship Dynamics
A particularly relevant question is what happens to attraction when a woman discontinues HBC, especially if she met her partner while taking the medication. The “congruency hypothesis” suggests that if a partner was chosen based on altered preferences while on HBC, stopping the medication may lead to a shift back to natural, cycle-driven preferences. This change can create a mismatch between the chosen partner and the woman’s newly restored natural attraction patterns. Studies exploring the long-term satisfaction of couples who initiated their relationship while the woman was using HBC indicate that women who stopped the pill after meeting their partner may experience a decline in sexual satisfaction and attraction toward that partner. This suggests that the initial choice made under hormonal influence may not align with preferences once the body’s natural cycle is restored. Conversely, some studies suggest that women who met their partners while on HBC were more satisfied with non-sexual aspects of the relationship, such as financial stability or intelligence, reflecting the initial preference for a cooperative, stable mate.