Can Birth Control Pills Affect Mate Selection?

Little Known Side Effects of Oral Contraceptives

Nov 10, 2009

With any medication, there are side effects. But is it possible that the birth control pill can affect judgment on the dating scene for men and women?

Many women are aware of the common side effects of the birth control pill, either from friends or personal experience. It's normal for the pill to produce some side effects mimicking pregnancy: acne, breast tenderness, nausea, bloating, headaches, and a decrease in sex drive, for example. Since the pill releases hormones that stop ovulation, essentially convincing your body that it's pregnant, this makes sense.

Recent findings, however, suggest that another little known side effect may be emerging. Some claim it could even alter the path of human evolution, since it directly affects the gene pool of the future. Is it possible that the birth control pill can influence decisions regarding mate selection?

Aromas and Genetic Compatibility

When a man and woman interact, many factors can influence their attraction to one another. One of the most basic of these factors is the human sense of smell, particularly for the other's natural body odor. Hiding underneath that cologne lies the hint of aromatic molecules that indicate genetic compatibility, or major histocompatibility complex (MHC).

Human beings are programmed to select the best mates, i.e. those with a different MHC, to provide for a diverse set of genes for their children. These genes help to build strong immune systems in the next generation that can "recognize a broader range of foreign cells, making them more fit" (Bryner, 2008). Basically, they'll be the "fittest" to "survive" in the next stages of human evolution.

MHC-diverse couples not only have fewer fertility problems, but they also trend better in long-term relationships, leading happier lives together with fewer incidents of infidelity. "And the opposite is also true with matching-MHC couples showing less satisfaction and more wandering eyes" (Bryner, 2008).

Further, "the offspring of pill users are more homzygous than expected, possibly related to impaired immune function and decreased perceived health and attractiveness" (Garnder, 2009).

The MHC-Breakdown

New studies reveal, however, that women taking birth control pills prefer men with matching MHC odors, which can lead to a whole host of problems. As previously mentioned, couples who are very MHC-similar can face fertility and fidelity problems down the road. Further, once the woman discontinues the use of the pill, relationships tend to break down, "as odor perception plays a significant role in maintaining attraction to partners" (Bryner, 2008).

The cause, researchers suspect, is the "pregnant" state of the woman's body while on the pill. With ovulation ceasing and a pregnancy-range of hormones, women do not feel the need to seek out a mate (on an instinctive level). With her body "post-mating," even with her mind still in the singles' game, the pill has "mirrored a natural shift but at an inappropriate time" (Bryner, 2008).

The Effect on Men

But it might not just be the woman's choice that is affected: "The pill might affect choice of mates among members of both genders in a way that could hinder successful reproduction in the future" (Gardner, 2009). Typically, men are attracted to women who are ovulating rather than those who are not; with women on the pill mimicking a state of pregnancy, they are not ovulating. Therefore, a man's choice might be influenced by the pill as well (Gardner, 2009).

The copyright of the article Can Birth Control Pills Affect Mate Selection? in Women's Sexual Health is owned by Stephanie Haddad. Permission to republish Can Birth Control Pills Affect Mate Selection? in print or online must be granted by the author in writing.