Abstract
Previous studies in animals and humans show that genes in the major histocompatibility complex (MHC) influence individual odours and that females often prefer odour of MHC-dissimilar males, perhaps to increase offspring heterozygosity or reduce inbreeding. Women using oral hormonal contraceptives have been reported to have the opposite preference, raising the possibility that oral contraceptives alter female preference towards MHC similarity, with possible fertility costs. Here we test directly whether contraceptive pill use alters odour preferences using a longitudinal design in which women were tested before and after initiating pill use; a control group of non-users were tested with a comparable interval between test sessions. In contrast to some previous studies, there was no significant difference in ratings between odours of MHC-dissimilar and MHC-similar men among women during the follicular cycle phase. However, single women preferred odours of MHC-similar men, while women in relationships preferred odours of MHC-dissimilar men, a result consistent with studies in other species, suggesting that paired females may seek to improve offspring quality through extra-pair partnerships. Across tests, we found a significant preference shift towards MHC similarity associated with pill use, which was not evident in the control group. If odour plays a role in human mate choice, our results suggest that contraceptive pill use could disrupt disassortative mate preferences.
Highlights
Olfaction is important in both human and animal mate choice (e.g. Gosling & Roberts 2001; Havlicek et al 2008)
Since Yamazaki et al.’s (1976) discovery that mice prefer to mate with individuals of different major histocompatibility complex (MHC)-congenic strains, and that this preference is mediated by chemosensory urinary cues ( Yamazaki et al 1979), MHC-associated and apparently odour-mediated mating preferences have been demonstrated in several vertebrate taxa, including fish (Olsen et al 1998), reptiles (Olsson et al 2003) and birds ( Freeman-Gallant et al 2003)
We found no effects of male heterozygosity on odour pleasantness, intensity or partnership desirability; mean pleasantness/ desirability scores were higher for heterozygotes in nonusers, and lower in pill users, but these differences did not approach significance
Summary
Olfaction is important in both human and animal mate choice (e.g. Gosling & Roberts 2001; Havlicek et al 2008). Olfaction is important in both human and animal mate choice One kind of information available from individual odours is an individual’s genotype at the major histocompatibility complex, MHC. Mate preference for MHC-dissimilar individuals can be adaptive as it would increase offspring MHC heterozygosity, with beneficial influences on offspring viability through increased resistance to infectious disease or avoidance of inbreeding effects (Potts & Wakeland 1993; Milinski 2006). MHC-correlated odour preferences have been demonstrated in humans. Cycling women tested during the follicular phase of their menstrual cycles rated odours of MHC-dissimilar men as more pleasant than odours of MHC-similar men (see Wedekind & Furi 1997). Odours of Electronic supplementary material is available at http://dx.doi.org/10. Odours of Electronic supplementary material is available at http://dx.doi.org/10. 1098/rspb.2008.0825 or via http://journals.royalsociety.org
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Proceedings of the Royal Society B: Biological Sciences
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
