The longstanding debate of whether love is a chemical reaction or an instinctual feeling takes on a whole new meaning with hormonal contraceptive pills. Emerging studies suggest that contraceptive pills may prevent more than just reproduction — they could also hinder one’s ability to choose a genetically ‘compatible’ partner. 

The role of hormonal contraceptives in mate selection 

Without the pill, menstruating women experiencing a natural ovulatory cycle tend to be attracted to genetically diverse partners, or partners with varying features and traits. This evolutionary preference exists because greater genetic diversity is generally correlated to improved survival and reproductive success.

Low genetic diversity can lead to harmful mutations, making populations more vulnerable to diseases and less adaptable to environmental changes. This preference can manifest as an attraction to particular body odours, which are thought to signal immune system diversity — variation that may foreshadow better offspring health. 

Contraceptive pills work by suppressing ovulation, including a hormonal profile closer to that of pregnancy, which results in non-permanent fertility loss. Due to this hormonal shift, heterosexual women on the pill may be more inclined to choose a partner based on qualities associated with being a ‘better father’ rather than relying on their evolutionary instincts to favour genetically compatible partners. 

This shift in preference can also extend to body odour, where women on the pill become more attracted to scents resembling those of their close genetic relatives. Theoretically, the scents evoke a sense of familiarity and reliability, rather than prioritizing genetic variation. 

To what extent does stopping birth control affect attraction? 

A recent article in Psychology Today explores this phenomenon, drawing on research published in Evolutionary Psychological Science. The aftereffects of discontinuing the pill were examined in two studies, which looked into the potential increase in attraction to alternative partners and its impact on long-term relationship satisfaction. 

The premise of these studies is that when partners form a connection, they tend to safeguard the relationship by diminishing the appeal of alternative mates. 

To test this, the first experiment examined committed women who had used hormonal contraceptives (HCs) when they met their current partner but later stopped. The researchers wanted to know if these women were more likely to express sexual interest in an attractive ‘bad boy’ — an alternative partner — over the average, dependable option, particularly during their high-fertility phase. The second experiment focused on visual attractiveness, excluding any mention of character traits in the alternative partners. 

The study found that women who had discontinued HCs were more likely to prefer attractive alternative partners, suggesting that discontinuing HCs may be correlated with a lower motivation to protect relationships by devaluing potential mates. 

Caution amidst compelling findings 

Despite the compelling nature of these findings, caution is needed before embracing them as definitive truth. The two prominent studies driving this discussion come with their own set of limitations. For example, the studies relied on self-reported measures of attractiveness from romantically involved women and only measured correlations, not causality.

It is important to acknowledge that expressed preferences may not necessarily align with real-world behaviour. Future studies, spanning a longer duration, that examine relationship status and satisfaction during and after HC use are needed to draw more confident conclusions.

Though hormonal contraceptives are used for the intended purpose, their impact extends beyond contraception into the realm of partner preferences and relationship dynamics. Since its creation, extensive research has highlighted the biological side effects of taking birth control. 

By understanding the effects of the pill during both its initiation and withdrawal, couples can be better equipped to navigate the evolving nature of their relationships and maintain harmony and contentment.