Resistance to disease is greater for offspring if the parents have dissimilar immune systems, as their pathogen-detection ability is enhanced. Accordingly, women evolved to be sexually attracted to men with a dissimilar immune system, primarily during high-fertility cycle phases. Contraceptive pills, however, reverse women’s preferences, leading them to be attracted to men with a similar immune system. In the present study (N = 192), we compared the health of children born to parents who met while the mother was on the pill with that of children whose parents met when the mother was not on the pill. Results confirmed our predictions, indicating that children to mothers who were on the pill are more infection-prone, require more medical care, suffer from a higher frequency of common sicknesses, and are perceived as generally less healthy than children whose parents met on non-pill circumstances. Results are discussed in light of the current antibiotic world crisis.
People often use the expression “it smells funny to me.” Research has recently indicated that when it comes to roman-tic partners, people should indeed follow their nose: the more they like their partner’s body odor, the better the genetic fit is with respect to immune system benefits for potential children (Roberts et al. 2013). Unfortunately, the commonly used contraceptive pills may cancel out these potential benefits. When women use contraceptive pills, which imitate a state of pregnancy (Alvergne and Lummaa 2010), their natural odor preference for good-fitting romantic partners is reversed, such that they switch to preferring the odor of poorly fitting partners (Wedekind and Füri 1997; Wedekind et al. 1995). To date, it is still unclear whether this shift in mate preference affects the health of children born to couples who have met while the woman was on pills. In the present study, we examined this possibility by comparing the health of children born to parents who met while the mother was on contraceptive pills with the health of those whose mother was not on pills.