Open main menu

Wikipedia β

Ovulatory shift hypothesis

The ovulatory shift hypothesis is the theory that women experience evolutionarily adaptive changes in thoughts and behaviors related to mating across the ovulatory cycle.[1][2] It proposes that hormonal changes across the cycle cause women, when they are most likely to get pregnant, to be more attracted to traits in potential short-term male sexual partners that indicate high genetic quality, leading to greater reproductive success.[1][3] Some of these proposed traits are physical features like symmetry[4][1] and masculinity,[5] while others are personality traits like dominance[6] and creativity.[7] The theory also proposes that women's behavior may change during the most fertile time in their ovulatory cycle. They may experience increased sexual desire,[8] dress more provocatively,[9] become more competitive with other women,[10] and flirt with men more frequently,[11] even if they currently have a romantic partner.[12] The theory is based on the principles of evolutionary psychology and has been extensively researched by scientists in the fields of psychology, biological anthropology, and evolutionary biology.

Related research has shown that both men and other women may be able to subconsciously detect when a woman is in the most fertile phase of her ovulatory cycle. Women in the fertile phase are often rated as being more physically attractive, smelling more attractive, and having higher-pitched voices.[13]

While many studies have demonstrated strong evidence in support of the ovulatory shift hypothesis, some studies have also failed to show significant effects for some predictions of the theory. Two meta-analyses published in 2014 reached opposing conclusions on whether or not the existing evidence was robust enough to support the prediction that women's mate preferences change across the cycle.[3][14]



Estrus in humansEdit

Most female mammals experience reproductive fertility cycles. They typically consist of a long period of low fertility, and a brief period of high fertility just prior to and including ovulation. In humans, this is called the ovulatory cycle, or menstrual cycle. The period of high fertility is also called the fertile window, and is the only time during the cycle when sex can result in conception.[15]

Females of most mammalian species exhibit hormonally-induced physical and behavioral signals of their fertility during the fertile window, such as sexual swellings and increased interest and motivation to mate.[16] Some species will not—or cannot—engage in sex at all outside of this window.[15] This phase of sexual receptivity and proceptivity is termed “estrus”, often referred to as being “in heat”.

Humans, however, engage in sex throughout their ovulatory cycles, and even beyond their reproductive years. Additionally, they do not show obvious physical signals of high fertility. This has led many researchers to conclude that humans “lost” their estrus through evolution.[17] It has been hypothesized that this could be due to the adaptive benefits of concealed ovulation and extended sexuality.[18][19]

However, recent research has shown that human females may in fact experience distinct physiological, behavioral, and cognitive changes during the high-fertility phase of their ovulatory cycle,[2][3] and that both men and other women can detect subtle signals that indicate high-fertility in a woman[13], which may indicate that humans have retained an estrus-like state.[20]

Evolution of ovulatory cycle shiftsEdit

Estrus evolved to facilitate reproduction and maximize reproductive success, or the success of passing on one's genes by producing offspring that are most likely to survive and reproduce themselves.[21][22] Thus, the ovulatory shift hypothesis proposes that motivation and desire to mate should increase during the fertile window, and that females should seek and attract the best possible mate at their highest fertility.[1] An ideal mate could have many qualities: resources to care for offspring, the physical ability and social status to protect and care for a mate and offspring, a compatible personality for a long-term pair bond, etc. Evolutionary theory and sexual selection theory suggest that an organism’s top priority should be to maximize survival and reproductive success.[22] Thus, the ovulatory shift hypothesis proposes that women possess a dual sexuality, where during the fertile window, a woman should prioritize attracting and choosing a mate with the best genetic quality, or “good genes”, since this is the only time she can become pregnant and pass on heritable genetic qualities to her offspring. However, at low-fertility, a woman should prioritize a mate with "good parenting" traits, such as willingness and ability to invest in parenting, resources to devote to offspring, and compatibility for a long-term partnership.[21] These differing traits are sometimes referred to as the "sexy cad" vs. the "good dad".[11][23]

It has also been hypothesized that high-fertility preferences should be strongest when evaluating a short-term sexual partner, but low-fertility preferences should be strongest when evaluating a long-term relationship partner.[3][24] A woman can gain the benefits of good genes through only a single sexual encounter, and good dad traits are only relevant for a long-term pair bond.

Some researchers have suggested that over evolutionary time, women may have maximized reproductive success by seeking good genes from an extra-pair copulation—cheating on their partner—at high fertility, while also maintaining a long-term pair bond with a partner who provides parenting resources for the offspring, sometimes called the dual strategy hypothesis.[25][26] Of course, an optimal partner is one with both sexy cad and good dad traits, but such a man is statistically unlikely to be common. Thus, natural selection may have designed ancestral women to be opportunistic. If successful, a woman could gain the benefits of both high-quality genetics and high-quality parenting to give her offspring the best chance of survival. However, natural selection would not have favored men who desire to provide for offspring that do not share their genes, so this would have been a risky strategy.[27]


Hormonal changes across the ovulatory cycle. Researchers hypothesize that changes in estradiol (blue) and progesterone (black) primarily drive changes in mating-related thoughts and behaviors.

Ovulatory cycle shifts are hypothesized to be regulated by sex hormones, primarily estradiol and progesterone, which become elevated at different times across the cycle. In particular, high levels of estradiol and low levels of progesterone, which peak at high fertility just prior to ovulation, have been shown to be correlated with several mating-related psychological changes.[28][29] However, some studies have only found correlations with changes in estradiol.[30][31] It is well-established that estradiol can act in the brain to produce other psychological and behavioral changes,[32] and animal studies tend to show a link between sexual behavior and estrogen concentrations.[33] Other hormones such as testosterone, follicle-stimulating hormone (FSH), luteinizing hormone (LH), and prolactin have been studied as possible correlates, but most have produced little to no effect.[30]

Changes in cognition and behavior across the ovulatory cycleEdit

Numerous studies have demonstrated ovulatory cycle shifts in women’s mating-related motivations, preferences, thoughts, and behaviors.[3] The ovulatory shift hypothesis proposes that these shifts are designed by natural selection as evolutionary adaptations for selecting and attracting specific types of mates with high genetic quality when a woman is most likely to get pregnant. 

Sexual desireEdit

Some of the earliest studies on human ovulatory shifts explored whether women engage in more instances of sexual activity during high fertility, as this could indicate a human estrus-like state. While some studies have found increases in frequency of sexual activity at high fertility,[34][35][36] larger studies have concluded that there is generally no difference in frequency of sexual activity across the ovulatory cycle,[37] possibly due to the multitude of factors that affect the ability to engage in sex (e.g., access to a partner, partner’s desire, time for engaging, etc.).

Researchers have subsequently explored whether sexual desire, rather than frequency of sexual activity, changes across the ovulatory cycle, as this would not be affected by practical barriers to engaging in sex. Studies in this area have largely shown that women’s sexual desire does increase during the fertile window,[8] although results have been mixed.[38]

Relationship satisfactionEdit

Consistent with the hypothesis that women may seek high quality genes from short-term extra-pair partners at high fertility, several studies have shown that fertile-phase women are more attracted to, flirt more, and initiate sex more often, with men who are not their partner.[2][12] In fact, women often report that attraction to their current partner does not increase during the fertile window, but both attraction and relationship satisfaction may actually decrease.[12][39] Studies have found that this effect is particularly strong when women are not highly attached to their current partner or do not perceive them to be highly sexually attractive.[40][41][42][43] Women in relationships also tend to be more assertive and independent during the fertile phase.[44] Additionally, researchers have shown that women at low fertility tend to initiate sex with their primary partner more frequently, consistent with the idea that women seek investment in a long-term relationship when they are not likely to get pregnant.[45]


While women in relationships may experience decreased relationship satisfaction and increased flirting with extra-pair partners during high fertility, studies have shown that single women at high-fertility also engage in more flirting behavior, and are more receptive to men's advances.[38][46] Women also flirt selectively with men described as "sexy cads" who display indicators of good genes, especially when considering them as short-term sexual partners.[11] Although women's attention to attractive men increases at high fertility, their memory for those men is not increased, consistent with the hypothesis that women would only be interested in them as short-term partners and would not need to remember them after ovulation has passed.[47]

Attraction and mate preferencesEdit

The ovulatory shift hypothesis proposes that women at high fertility should be most attracted to short-term sexual partners with physical and behavioral features that likely signal genetic fitness, or good genes.


Having symmetrical features may indicate that an individual possesses high-quality genes related to health, and that they developed in a stable environment with little disease or trauma.[48] Studies have found that women rate faces of more symmetrical men as more attractive during high fertility, especially when evaluating them as short-term partners.[24][4] It has also been demonstrated that women at high fertility are more attracted to the body odors of men with more facial and bodily symmetry.[49][50] Although many studies and one meta-analysis have shown that fertility-moderated shifts in attraction to facial and bodily symmetry occur robustly,[51] other reviews have concluded that the effect is small or non-existent.[52][14]


In many species, more masculine and dominant males experience greater reproductive success.[53] Masculine traits are produced during puberty by increasing amounts of testosterone. Testosterone is a known immunosuppressant, thus traits that reflect high levels of testosterone may indicate that a man possesses high-quality genes which allowed him to develop masculine features without experiencing any deleterious effects of high testosterone levels.[54] Masculine traits include facial features like a strong jawline,[55] bodily features like height, muscularity, and body hair,[56] and vocal features like a deeper voice.[57] While many studies have shown that women tend to be attracted to more masculine characteristics at high fertility,[5] results have been mixed,[58] and two meta-analyses have concluded that the effect is not robust.[52][51]


Most primates prefer to mate with dominant or high-ranking males at high fertility, as these mates could confer genetic, material, and social benefits.[59] Some studies have found that women at high fertility are more attracted to potential short-term male sexual partners who exhibit masculine behavioral traits like dominance, aggression, and confidence, and those who are more directly competitive with other men.[24][6][60] One study has even found that fertile-phase women find the scent of dominant men more attractive.[61]


Charles Darwin first proposed that music, lacking a functional evolutionary explanation by natural selection, may be an instrument of sexual selection, in that it may be used as a display of useful genetic qualities like creativity.[62][63] To this end, one study has found that women at high fertility preferred short-term partners described as creative over those described as wealthy.[7]

Compatible genesEdit

The major histocompatibility complex (MHC) is a suite of genes responsible for adaptive immune response and histocompatibility in an organism's cells. In animals, including mammals and other primates, MHC has been shown to play a role in MHC sexual selection, where organisms mate selectively with individuals who possess MHC alleles that are more dissimilar from their own.[64] MHC has been shown to be responsible for changing the pheromone compositions of mice, causing mice with dissimilar MHC genes to have more attractive body odors.[65] It has been hypothesized that this is a mechanism for creating genetic diversity, avoiding inbreeding, and creating offspring that are more resistant to pathogens. Some studies have shown that humans tend to form long-term partnerships with individuals who have more dissimilar MHC,[66] and find the scent of MHC-dissimilar individuals more attractive, especially at high fertility.[67][68] However, other studies have found little or no effect of MHC on mate preferences, and some have even shown a reverse effect, that people prefer partners with more similar MHC to their own.[69] Several reviews and one meta-analysis on the human and primate literature regarding MHC have concluded that the effects of MHC similarity on attraction are not robust,[70][71] but that humans are reliably attracted to individuals with more heterozygous, or diverse, MHC genotypes, regardless of whether they are similar to their own.[71] However, it is unclear whether attraction to MHC heterozygosity changes across the ovulatory cycle.

Clothing and groomingEdit

The ovulatory shift hypothesis proposes that women's behavior during the fertile phase should also reflect evolutionary adaptations for reproductive success, primarily through attempting to attract short-term mates of high-genetic quality. One avenue of this research has found that women tend to dress in clothing that is perceived to be more revealing, fashionable, or sexy at high fertility.[9] Fertile-phase women also spend more time on their appearance and tend to wear accessories like jewelry, makeup, or hairstyles that are perceived as trying to look more attractive.[72][73] Additionally, several studies have demonstrated that women tend to purchase more products related to enhancing their appearance, attractive clothing, shoes, or accessories, during the fertile window.[74][73]

Competitiveness with other womenEdit

Parental investment theory posits the idea that natural selection designed each sex to have different mating strategies based on how much investment the sex is required to devote to offspring for their survival.[75] The sex that invests more in offspring should be more intersexuality selective, or picky when choosing a sexual partner, because they have more time and resources to lose if they make a poor choice. The other sex should be more intrasexually competitive, or competitive with members of their same sex, in order to access and attract the more selective sex.[75] In humans, females are the sex that invests more in parenting, simply through the lengthy and taxing process of pregnancy and lactation, whereas males need only to contribute one act of sexual intercourse to pass on their genes. Thus, females are expected to be the more selective sex, and males are expected to be more competitive. However, unlike many species where males do not contribute to parenting at all, humans have a complex social structure that allows males to make significant and important investments in parenting effort. According to parental investment theory, this indicates that natural selection may have designed women to be somewhat competitive with other women for access to the best mates and potential fathers for their offspring.[76]

Some studies have indicated that women engage in more competitive behaviors with other women when they are at high fertility. During the fertile window, women not using hormonal contraceptives self-report increased feelings of intrasexual competitiveness, describe other women as less attractive, and use more dehumanizing terms when talking about women, but not men.[10][77] Women's choices to purchase more attractive or revealing clothing at high fertility are also increased when they are first primed with a photograph of an attractive woman, but not photographs of men or unattractive women, suggesting clothing may not be chosen to attract men, but rather as a competitive display for other women.[74] Additionally, some studies have used economic games to show that women are less likely to share resources or engage in cooperative bargaining with other women during the fertile window.[78][79][80]

However, some researchers have noted that the reason why women should be more competitive during the fertile window is unclear.[80] The ovulatory shift hypothesis proposes that women should be seeking short-term sexual partners at peak fertility, but men can effectively have multiple sexual partners, so competition over one high-quality man should not be necessary. If women were competing for a long-term partner, there is no reason why they should be more competitive during the fertile window than any other time in their cycle.

Detecting ovulatory cycle shiftsEdit

In related research, there is evidence that both men and women can subconsciously detect cues to women's fertility that change across the ovulatory cycle.[81] Some researchers have suggested that natural selection designed women to signal their fertility in order to attract a mate.[82] However, other researchers have proposed that women evolved to have concealed ovulation but they still "leak" subtle cues of their fertility and men have evolved to detect them.[18][19][20]

Lap dancer tipsEdit

One of the first modern studies to explore whether women have truly concealed ovulation utilized a simple task: have professional lap dancers record the amount of tips they receive for each day of their ovulatory cycle. The study found that women not using hormonal contraceptives earned significantly more money on the days they were most fertile, compared to other days in the cycle.[83] The researchers suggest that this may indicate that women do possess an estrus phase and that their ovulation is not completely concealed.

Body odorEdit

During estrus, many species produce pheromones, or body odors that indicate to potential mates that one is in the fertile phase. While no specific human pheromones have yet been identified, there is evidence that humans may exhibit similar scent changes at high fertility. Body odors of high-fertility women not using hormonal contraceptives are rated more attractive by both men and women.[84][29][85] Vaginal odors from high-fertility women are also rated as more attractive than odors from the same women at low-fertility.[86] Additionally, some studies have shown that men exposed to high-fertility body odors of women exhibit increases in testosterone,[82] a feature that is associated with mating motivation and behavior, although other studies have failed to replicate this effect.

Physical attractivenessEdit

Researchers have found that both men and women rate physical features of women at high fertility more attractive than when they are at low fertility. Facial attractiveness has been shown to increase in fertile phase women.[87][88] It has been hypothesized that this shift may be due to subtle changes in soft tissue symmetry that increase during high-fertility.[89][90]

Vocal pitchEdit

Studies have found that fertile phase women speak with a slightly higher vocal pitch.[91] Recordings of women's voices in the fertile phase are rated as more attractive than recordings by the same women during low fertility by both men and women.[92] However, these effect sizes are relatively small compared to other cues of ovulation.[81]

Partner jealousyEdit

Several studies have found that men in a relationship tend to be more protective and possessive of their partner when she is at peak fertility, as well as more jealous of any advances their partner might make on other men.[38][41][44] One study also demonstrated that after interacting with their partner during the fertile phase, men shown a photograph of an attractive man exhibit increased testosterone, which may be a competitive response.[93]

Effects of hormonal contraceptionEdit

Since it has been proposed that changes in hormone levels across the ovulatory cycle are the primary mechanisms that causes cycle shifts, some studies have explored the effects of hormonal contraception, like the pill, on both women’s cycle shifts and other's ability to detect cycle shifts.

Most studies have reported that hormonal contraceptives weaken or eliminate cycle shifts entirely.[94] It has been proposed that the synthetic hormones present in hormonal contraception that suppress ovulation also suppress the subsequent cognitive and behavioral effects found in naturally-cycling women. Other studies have concluded that changes in synthetic hormones produce cycle shifts similar to effects produced by the real hormonal changes in naturally-cycling women.[95] The precise effects of each hormone on cycle shifts, and the effects of each synthetic hormone present in different types of contraceptive, are not well understood.

Alternative hypothesesEdit

Within-cycle vs. between-cycle shiftsEdit

While the ovulatory shift hypothesis proposes that adaptive changes in mating-related cognition and behavior occur within each ovulatory cycle, some researchers have posited a between-cycle shift theory. Many women experience regular anovulatory cycles, or non-fertile cycles where ovulation does not occur, therefore hormonal changes between ovulatory cycles may be a more reliable indicator of true fertility, as higher levels of estradiol are more likely to produce a fertile ovulatory cycle.[96] Thus, some researchers have proposed that hormonal changes between cycles, primarily in elevated estradiol levels, are responsible for changes in mating-related cognition and behavior.[97][98][99] Within-cycle shifts may be simply a byproduct of between-cycle shifts caused by elevated estradiol.[20]

Meta-analyses of ovulatory cycle shift literatureEdit

One meta-analysis and several reviews of the literature have been conducted on both published and unpublished data that support the claim of the ovulatory shift hypothesis that women experience changes in attraction preferences at high fertility.[3][24] However, another meta-analysis and subsequent commentary concluded that the effect is not actually significant and may be a result of some studies using imprecise measurements of when women are in the fertile window, as well as publication bias.[14][100] The authors of the former meta-analysis subsequently published a p-curve analysis, a statistical test which supports the claim that the effects are not a result of publication bias or p-hacking, and concluded that the methodology used by the latter meta-analysis caused the authors to overlook patterns of robust effects in cycle shifts.[101]

See alsoEdit


  1. ^ a b c d Gangestad, Steven W.; Thornhill, Randy (1998-05-22). "Menstrual cycle variation in women's preferences for the scent of symmetrical men". Proceedings of the Royal Society of London B: Biological Sciences. 265 (1399): 927–933. doi:10.1098/rspb.1998.0380. ISSN 0962-8452. PMID 9633114. 
  2. ^ a b c Gangestad, Steven W.; Thornhill, Randy (2008-05-07). "Human oestrus". Proceedings of the Royal Society of London B: Biological Sciences. 275 (1638): 991–1000. doi:10.1098/rspb.2007.1425. ISSN 0962-8452. PMID 18252670. 
  3. ^ a b c d e f Gildersleeve, Kelly; Haselton, Martie G.; Fales, Melissa R. "Do women's mate preferences change across the ovulatory cycle? A meta-analytic review". Psychological Bulletin. 140 (5): 1205–1259. doi:10.1037/a0035438. 
  4. ^ a b Little, Anthony C.; Jones, Benedict C.; Burt, D. Michael; Perrett, David I. "Preferences for symmetry in faces change across the menstrual cycle". Biological Psychology. 76 (3): 209–216. doi:10.1016/j.biopsycho.2007.08.003. 
  5. ^ a b Puts, David Andrew (2006). "Cyclic variation in women's preferences for masculine traits: Potential hormonal causes". Human Nature: 114–127. 
  6. ^ a b Flowe, Heather D.; Swords, Elizabeth; Rockey, James C. "Women's behavioural engagement with a masculine male heightens during the fertile window: evidence for the cycle shift hypothesis". Evolution and Human Behavior. 33 (4): 285–290. doi:10.1016/j.evolhumbehav.2011.10.006. 
  7. ^ a b Haselton, Martie G.; Miller, Geoffrey F. (2006-03-01). "Women's fertility across the cycle increases the short-term attractiveness of creative intelligence". Human Nature. 17 (1): 50–73. doi:10.1007/s12110-006-1020-0. ISSN 1045-6767. 
  8. ^ a b Roney, James R.; Simmons, Zachary L. "Hormonal predictors of sexual motivation in natural menstrual cycles". Hormones and Behavior. 63 (4): 636–645. doi:10.1016/j.yhbeh.2013.02.013. 
  9. ^ a b Durante, Kristina M.; Li, Norman P.; Haselton, Martie G. (2008-11-01). "Changes in Women's Choice of Dress Across the Ovulatory Cycle: Naturalistic and Laboratory Task-Based Evidence". Personality and Social Psychology Bulletin. 34 (11): 1451–1460. doi:10.1177/0146167208323103. ISSN 0146-1672. 
  10. ^ a b Fisher, M. L. (2004-08-07). "Female intrasexual competition decreases female facial attractiveness". Proceedings of the Royal Society of London B: Biological Sciences. 271 (Suppl 5): S283–S285. doi:10.1098/rsbl.2004.0160. ISSN 0962-8452. PMID 15503995. 
  11. ^ a b c Cantú, Stephanie M.; Simpson, Jeffry A.; Griskevicius, Vladas; Weisberg, Yanna J.; Durante, Kristina M.; Beal, Daniel J. (2013-12-13). "Fertile and Selectively Flirty". Psychological Science. 25 (2): 431–438. doi:10.1177/0956797613508413. 
  12. ^ a b c Gangestad, S. W.; Thornhill, R.; Garver, C. E. (2002-05-07). "Changes in women's sexual interests and their partner's mate–retention tactics across the menstrual cycle: evidence for shifting conflicts of interest". Proceedings of the Royal Society of London B: Biological Sciences. 269 (1494): 975–982. doi:10.1098/rspb.2001.1952. ISSN 0962-8452. PMID 12028782. 
  13. ^ a b Haselton, Martie G.; Gildersleeve, Kelly (2011-04-01). "Can Men Detect Ovulation?". Current Directions in Psychological Science. 20 (2): 87–92. doi:10.1177/0963721411402668. ISSN 0963-7214. 
  14. ^ a b c Wood, Wendy; Kressel, Laura; Joshi, Priyanka D.; Louie, Brian (2014-03-24). "Meta-Analysis of Menstrual Cycle Effects on Women's Mate Preferences". Emotion Review. 6 (3): 229–249. doi:10.1177/1754073914523073. 
  15. ^ a b Randy., Nelson, (2015). Intro to behavioral endocrinology. [Place of publication not identified]: Sinauer Associates. ISBN 1605353825. OCLC 925498570. 
  16. ^ F., Dixson, Alan (2012). Primate sexuality : comparative studies of the prosimians, monkeys, apes, and humans (2nd ed ed.). Oxford: Oxford University Press. ISBN 0199676615. OCLC 778123209. 
  17. ^ Social behavior and organization among vertebrates. Etkin, William (5. impr ed.). Chicago: University of Chicago Pr. 1972. ISBN 0226220362. OCLC 245881483. 
  18. ^ a b Evolutionary biology and human social behavior : an anthropological perspective. Chagnon, Napoleon A., 1938-, Irons, William., American Anthropological Association. North Scituate, Mass.: Duxbury Press. 1979. ISBN 0878721932. OCLC 4135550. 
  19. ^ a b Randy., Thornhill, (2008). The evolutionary biology of human female sexuality. Gangestad, Steven W. Oxford: Oxford University Press. ISBN 0195340981. OCLC 265732721. 
  20. ^ a b c Gangestad, Steven W; Haselton, Martie G. "Human estrus: implications for relationship science". Current Opinion in Psychology. 1: 45–51. doi:10.1016/j.copsyc.2014.12.007. 
  21. ^ a b The handbook of evolutionary psychology. Buss, David M., (2nd edition ed.). Hoboken, New Jersey. ISBN 111875588X. OCLC 905450212. 
  22. ^ a b 1941-, Dawkins, Richard,. The selfish gene (40th anniversary edition ed.). Oxford. ISBN 0198788606. OCLC 952666572. 
  23. ^ Durante, Kristina M.; Griskevicius, Vladas; Simpson, Jeffry A.; Cantú, Stephanie M.; Li, Norman P. "Ovulation leads women to perceive sexy cads as good dads". Journal of Personality and Social Psychology. 103 (2): 292–305. doi:10.1037/a0028498. 
  24. ^ a b c d Gangestad, Steven W.; Garver-Apgar, Christine E.; Simpson, Jeffry A.; Cousins, Alita J. "Changes in women's mate preferences across the ovulatory cycle". Journal of Personality and Social Psychology. 92 (1): 151–163. doi:10.1037/0022-3514.92.1.151. 
  25. ^ Eastwick, Paul W. "Beyond the pleistocene: Using phylogeny and constraint to inform the evolutionary psychology of human mating". Psychological Bulletin. 135 (5): 794–821. doi:10.1037/a0016845. 
  26. ^ Randy., Thornhill, (2008). The evolutionary biology of human female sexuality. Gangestad, Steven W. Oxford: Oxford University Press. ISBN 0195340981. OCLC 265732721. 
  27. ^ MA, Elizabeth G. Pillsworth; PhD, Martie G. Haselton (2006-03-01). "Women's Sexual Strategies: The Evolution of Long-Term Bonds and Extrapair Sex". Annual Review of Sex Research. 17 (1): 59–100. doi:10.1080/10532528.2006.10559837. ISSN 1053-2528. 
  28. ^ Puts, David A. (2010-05-01). "Beauty and the beast: mechanisms of sexual selection in humans". Evolution and Human Behavior. 31 (3): 157–175. doi:10.1016/j.evolhumbehav.2010.02.005. 
  29. ^ a b Garver-Apgar, Christine E.; Gangestad, Steven W.; Thornhill, Randy (2003). "Hormonal correlates of women's mid-cycle preference for the scent of symmetry". Evolution and Human Behavior. 29 (4): 223–232. doi:10.1016/j.evolhumbehav.2007.12.007. 
  30. ^ a b Lukaszewski, Aaron W.; Roney, James R. "Estimated hormones predict women's mate preferences for dominant personality traits". Personality and Individual Differences. 47 (3): 191–196. doi:10.1016/j.paid.2009.02.019. 
  31. ^ Roney, James R.; Simmons, Zachary L. "Women's estradiol predicts preference for facial cues of men's testosterone". Hormones and Behavior. 53 (1): 14–19. doi:10.1016/j.yhbeh.2007.09.008. 
  32. ^ Douma, S. L.; Husband, C.; OʼDonnell, M. E.; Barwin, B. N.; Woodend, A. K. "Estrogen-related Mood Disorders". Advances in Nursing Science. 28 (4): 364–375. doi:10.1097/00012272-200510000-00008. 
  33. ^ Simerly, Richard B. (2002-03-01). "Wired for Reproduction: Organization and Development of Sexually Dimorphic Circuits in the Mammalian Forebrain". Annual Review of Neuroscience. 25 (1): 507–536. doi:10.1146/annurev.neuro.25.112701.142745. ISSN 0147-006X. 
  34. ^ Wilcox, A.J. (2004-07-01). "On the frequency of intercourse around ovulation: evidence for biological influences". Human Reproduction. 19 (7): 1539–1543. doi:10.1093/humrep/deh305. ISSN 0268-1161. 
  35. ^ Adams, David B.; Gold, Alice Ross; Burt, Anne D. (1978-11-23). "Rise in Female-Initiated Sexual Activity at Ovulation and Its Suppression by Oral Contraceptives". New England Journal of Medicine. 299 (21): 1145–1150. doi:10.1056/nejm197811232992101. ISSN 0028-4793. PMID 703805. 
  36. ^ UDRY, J. RICHARD; MORRIS, NAOMI M. (1968-11-09). "Distribution of Coitus in the Menstrual Cycle". Nature. 220 (5167): 593–596. doi:10.1038/220593a0. ISSN 1476-4687. 
  37. ^ Brewis, Alexandra; Meyer, Mary. "Demographic Evidence That Human Ovulation Is Undetectable (At Least in Pair Bonds)". Current Anthropology. 46 (3): 465–471. doi:10.1086/430016. 
  38. ^ a b c Haselton, Martie G.; Gangestad, Steven W. "Conditional expression of women's desires and men's mate guarding across the ovulatory cycle". Hormones and Behavior. 49 (4): 509–518. doi:10.1016/j.yhbeh.2005.10.006. 
  39. ^ Gangestad, Steven W.; Thornhill, Randy; Garver-Apgar, Christine E. (2005-10-07). "Women's sexual interests across the ovulatory cycle depend on primary partner developmental instability". Proceedings of the Royal Society of London B: Biological Sciences. 272 (1576): 2023–2027. doi:10.1098/rspb.2005.3112. ISSN 0962-8452. PMID 16191612. 
  40. ^ Larson, Christina M.; Haselton, Martie G.; Gildersleeve, Kelly A.; Pillsworth, Elizabeth G. "Changes in women's feelings about their romantic relationships across the ovulatory cycle". Hormones and Behavior. 63 (1): 128–135. doi:10.1016/j.yhbeh.2012.10.005. 
  41. ^ a b Pillsworth, Elizabeth G.; Haselton, Martie G. "Male sexual attractiveness predicts differential ovulatory shifts in female extra-pair attraction and male mate retention". Evolution and Human Behavior. 27 (4): 247–258. doi:10.1016/j.evolhumbehav.2005.10.002. 
  42. ^ Larson, Christina M.; Pillsworth, Elizabeth G.; Haselton, Martie G. (2012-09-12). "Ovulatory Shifts in Women's Attractions to Primary Partners and Other Men: Further Evidence of the Importance of Primary Partner Sexual Attractiveness". PLOS ONE. 7 (9): e44456. doi:10.1371/journal.pone.0044456. ISSN 1932-6203. 
  43. ^ Eastwick, Paul W.; Finkel, Eli J. (2011-09-20). "The Evolutionary Armistice". Personality and Social Psychology Bulletin. 38 (2): 174–184. doi:10.1177/0146167211422366. 
  44. ^ a b Gangestad, Steven W.; Garver-Apgar, Christine E.; Cousins, Alita J.; Thornhill, Randy. "Intersexual conflict across women's ovulatory cycle". Evolution and Human Behavior. 35 (4): 302–308. doi:10.1016/j.evolhumbehav.2014.02.012. 
  45. ^ Grebe, Nicholas M.; Gangestad, Steven W.; Garver-Apgar, Christine E.; Thornhill, Randy (2013-08-21). "Women's Luteal-Phase Sexual Proceptivity and the Functions of Extended Sexuality". Psychological Science. 24 (10): 2106–2110. doi:10.1177/0956797613485965. 
  46. ^ Guéguen, Nicolas. "Menstrual cycle phases and female receptivity to a courtship solicitation: an evaluation in a nightclub". Evolution and Human Behavior. 30 (5): 351–355. doi:10.1016/j.evolhumbehav.2009.03.004. 
  47. ^ Anderson, Uriah S.; Perea, Elaine F.; Becker, D. Vaughn; Ackerman, Joshua M.; Shapiro, Jenessa R.; Neuberg, Steven L.; Kenrick, Douglas T. "I only have eyes for you: Ovulation redirects attention (but not memory) to attractive men". Journal of Experimental Social Psychology. 46 (5): 804–808. doi:10.1016/j.jesp.2010.04.015. 
  48. ^ Van Dongen, Stefan; Gangestad, Steven W. (2011-11-01). "Human fluctuating asymmetry in relation to health and quality: a meta-analysis". Evolution and Human Behavior. 32 (6): 380–398. doi:10.1016/j.evolhumbehav.2011.03.002. 
  49. ^ Gangestad, Steven W.; Thornhill, Randy (1998-05-22). "Menstrual cycle variation in women's preferences for the scent of symmetrical men". Proceedings of the Royal Society of London B: Biological Sciences. 265 (1399): 927–933. doi:10.1098/rspb.1998.0380. ISSN 0962-8452. PMID 9633114. 
  50. ^ Thornhill, R. (2003-09-01). "Major histocompatibility complex genes, symmetry, and body scent attractiveness in men and women". Behavioral Ecology. 14 (5): 668–678. doi:10.1093/beheco/arg043. ISSN 1045-2249. 
  51. ^ a b Gildersleeve, Kelly; Haselton, Martie G.; Fales, Melissa R. "Do women's mate preferences change across the ovulatory cycle? A meta-analytic review". Psychological Bulletin. 140 (5): 1205–1259. doi:10.1037/a0035438. 
  52. ^ a b Peters, Marianne; Simmons, Leigh W.; Rhodes, Gillian (2009-01-07). "Preferences across the Menstrual Cycle for Masculinity and Symmetry in Photographs of Male Faces and Bodies". PLoS ONE. 4 (1). doi:10.1371/journal.pone.0004138. ISSN 1932-6203. PMC 2607552 . PMID 19127295. 
  53. ^ Fiske, Peder; Rintamäki, Pekka T.; Karvonen, Eevi (1998-01-01). "Mating success in lekking males: a meta-analysis". Behavioral Ecology. 9 (4): 328–338. doi:10.1093/beheco/9.4.328. ISSN 1045-2249. 
  54. ^ Folstad, Ivar; Karter, Andrew John. "Parasites, Bright Males, and the Immunocompetence Handicap". The American Naturalist. 139 (3): 603–622. doi:10.1086/285346. 
  55. ^ Penton-Voak, I. S.; Perrett, D. I.; Castles, D. L.; Kobayashi, T.; Burt, D. M.; Murray, L. K.; Minamisawa, R. (1999). "Menstrual cycle alters face preference". Nature. 399 (6738): 741–742. doi:10.1038/21557. ISSN 1476-4687. 
  56. ^ Little, Anthony C.; Jones, Benedict C.; Burriss, Robert P. "Preferences for masculinity in male bodies change across the menstrual cycle". Hormones and Behavior. 51 (5): 633–639. doi:10.1016/j.yhbeh.2007.03.006. 
  57. ^ Feinberg, D.R.; Jones, B.C.; Smith, M.J. Law; Moore, F.R.; DeBruine, L.M.; Cornwell, R.E.; Hillier, S.G.; Perrett, D.I. "Menstrual cycle, trait estrogen level, and masculinity preferences in the human voice". Hormones and Behavior. 49 (2): 215–222. doi:10.1016/j.yhbeh.2005.07.004. 
  58. ^ Scott, Isabel M.; Clark, Andrew P.; Josephson, Steven C.; Boyette, Adam H.; Cuthill, Innes C.; Fried, Ruby L.; Gibson, Mhairi A.; Hewlett, Barry S.; Jamieson, Mark (2014-10-07). "Human preferences for sexually dimorphic faces may be evolutionarily novel". Proceedings of the National Academy of Sciences. 111 (40): 14388–14393. doi:10.1073/pnas.1409643111. ISSN 0027-8424. PMID 25246593. 
  59. ^ F., Dixson, Alan (2012). Primate sexuality : comparative studies of the prosimians, monkeys, apes, and humans (2nd ed ed.). Oxford: Oxford University Press. ISBN 0199676615. OCLC 778123209. 
  60. ^ Gangestad, Steven W.; Simpson, Jeffry A.; Cousins, Alita J.; Garver-Apgar, Christine E.; Christensen, P. Niels (2016-05-06). "Women's Preferences for Male Behavioral Displays Change Across the Menstrual Cycle". Psychological Science. 15 (3): 203–207. doi:10.1111/j.0956-7976.2004.01503010.x. 
  61. ^ Havlicek, Jan; Roberts, S. Craig; Flegr, Jaroslav (2005-09-22). "Women's preference for dominant male odour: effects of menstrual cycle and relationship status". Biology Letters. 1 (3): 256–259. doi:10.1098/rsbl.2005.0332. ISSN 1744-9561. PMID 17148181. 
  62. ^ Darwin, Charles (1871). The descent of man, and selection in relation to sex. London: John Murray. 
  63. ^ F., Miller, Geoffrey (2000). The mating mind : how sexual choice shaped the evolution of human nature (1st ed ed.). New York: Doubleday. ISBN 0385495161. OCLC 43648482. 
  64. ^ Yamazaki, K.; Boyse, E. A.; Miké, V.; Thaler, H. T.; Mathieson, B. J.; Abbott, J.; Boyse, J.; Zayas, Z. A.; Thomas, L. (1976-11-02). "Control of mating preferences in mice by genes in the major histocompatibility complex". Journal of Experimental Medicine. 144 (5): 1324–1335. doi:10.1084/jem.144.5.1324. ISSN 0022-1007. PMID 1032893. 
  65. ^ Leinders-Zufall, Trese; Brennan, Peter; Widmayer, Patricia; S, Prashanth Chandramani; Maul-Pavicic, Andrea; Jäger, Martina; Li, Xiao-Hong; Breer, Heinz; Zufall, Frank (2004-11-05). "MHC Class I Peptides as Chemosensory Signals in the Vomeronasal Organ". Science. 306 (5698): 1033–1037. doi:10.1126/science.1102818. ISSN 0036-8075. PMID 15528444. 
  66. ^ Chaix, Raphaëlle; Cao, Chen; Donnelly, Peter (2008-09-12). "Is Mate Choice in Humans MHC-Dependent?". PLOS Genetics. 4 (9): e1000184. doi:10.1371/journal.pgen.1000184. ISSN 1553-7404. 
  67. ^ Roberts, S. Craig; Gosling, L. Morris; Carter, Vaughan; Petrie, Marion (2008-12-07). "MHC-correlated odour preferences in humans and the use of oral contraceptives". Proceedings of the Royal Society of London B: Biological Sciences. 275 (1652): 2715–2722. doi:10.1098/rspb.2008.0825. ISSN 0962-8452. PMID 18700206. 
  68. ^ Wedekind, Claus; Füri, Sandra (1997-10-22). "Body odour preferences in men and women: do they aim for specific MHC combinations or simply heterozygosity?". Proceedings of the Royal Society of London B: Biological Sciences. 264 (1387): 1471–1479. doi:10.1098/rspb.1997.0204. ISSN 0962-8452. PMID 9364787. 
  69. ^ Rosenberg, Leon T.; Cooperman, Debra; Payn, Rose (1983-01-01). "HLA and mate selection". Immunogenetics. 17 (1): 89–93. doi:10.1007/BF00364292. ISSN 0093-7711. 
  70. ^ Havlicek, Jan; Roberts, S. Craig. "MHC-correlated mate choice in humans: A review". Psychoneuroendocrinology. 34 (4): 497–512. doi:10.1016/j.psyneuen.2008.10.007. 
  71. ^ a b Winternitz, J.; Abbate, J. L.; Huchard, E.; Havlíček, J.; Garamszegi, L. Z. (2017-01-01). "Patterns of MHC-dependent mate selection in humans and nonhuman primates: a meta-analysis". Molecular Ecology. 26 (2): 668–688. doi:10.1111/mec.13920. ISSN 1365-294X. 
  72. ^ Haselton, Martie G.; Mortezaie, Mina; Pillsworth, Elizabeth G.; Bleske-Rechek, April; Frederick, David A. "Ovulatory shifts in human female ornamentation: Near ovulation, women dress to impress". Hormones and Behavior. 51 (1): 40–45. doi:10.1016/j.yhbeh.2006.07.007. 
  73. ^ a b Saad, Gad; Stenstrom, Eric. "Calories, beauty, and ovulation: The effects of the menstrual cycle on food and appearance-related consumption". Journal of Consumer Psychology. 22 (1): 102–113. doi:10.1016/j.jcps.2011.10.001. 
  74. ^ a b Durante, Kristina M.; Griskevicius, Vladas; Hill, Sarah E.; Perilloux, Carin; Li, Norman P. (2011-04-01). "Ovulation, Female Competition, and Product Choice: Hormonal Influences on Consumer Behavior". Journal of Consumer Research. 37 (6): 921–934. doi:10.1086/656575. ISSN 0093-5301. 
  75. ^ a b Sexual selection and the descent of man : the Darwinian pivot. Campbell, Bernard Grant. New Brunswick (U.S.A.): AldineTransaction. 2006. ISBN 0202308456. OCLC 62857839. 
  76. ^ Rosvall, Kimberly A. (2011-11-01). "Intrasexual competition in females: evidence for sexual selection?". Behavioral Ecology. 22 (6): 1131–1140. doi:10.1093/beheco/arr106. ISSN 1045-2249. 
  77. ^ Piccoli, Valentina; Foroni, Francesco; Carnaghi, Andrea (2013-08-08). "Comparing Group Dehumanization and Intra-Sexual Competition Among Normally Ovulating Women and Hormonal Contraceptive Users". Personality and Social Psychology Bulletin. 39 (12): 1600–1609. doi:10.1177/0146167213499025. 
  78. ^ Lucas, Margery M.; Koff, Elissa; Skeath, Susan (2016-09-01). "Pilot Study of Relationship between Fertility Risk and Bargaining". Psychological Reports. 101 (1): 302–310. doi:10.2466/pr0.101.1.302-310. 
  79. ^ Lucas, Margery; Koff, Elissa. "How conception risk affects competition and cooperation with attractive women and men". Evolution and Human Behavior. 34 (1): 16–22. doi:10.1016/j.evolhumbehav.2012.08.001. 
  80. ^ a b Eisenbruch, Adar B.; Roney, James R. "Conception Risk and the Ultimatum Game: When Fertility is High, Women Demand More". Personality and Individual Differences. 98: 272–274. doi:10.1016/j.paid.2016.04.047. 
  81. ^ a b Haselton, Martie G.; Gildersleeve, Kelly (2011-04-15). "Can Men Detect Ovulation?". Current Directions in Psychological Science. 20 (2): 87–92. doi:10.1177/0963721411402668. 
  82. ^ a b Miller, Saul L.; Maner, Jon K. (2009-12-22). "Scent of a Woman". Psychological Science. 21 (2): 276–283. doi:10.1177/0956797609357733. 
  83. ^ Miller, Geoffrey; Tybur, Joshua M.; Jordan, Brent D. "Ovulatory cycle effects on tip earnings by lap dancers: economic evidence for human estrus?☆". Evolution and Human Behavior. 28 (6): 375–381. doi:10.1016/j.evolhumbehav.2007.06.002. 
  84. ^ Gildersleeve, Kelly A.; Haselton, Martie G.; Larson, Christina M.; Pillsworth, Elizabeth G. "Body odor attractiveness as a cue of impending ovulation in women: Evidence from a study using hormone-confirmed ovulation". Hormones and Behavior. 61 (2): 157–166. doi:10.1016/j.yhbeh.2011.11.005. 
  85. ^ Kuukasjarvi, S. (2004-07-01). "Attractiveness of women's body odors over the menstrual cycle: the role of oral contraceptives and receiver sex". Behavioral Ecology. 15 (4): 579–584. doi:10.1093/beheco/arh050. ISSN 1045-2249. 
  86. ^ Doty, R. L.; Ford, M.; Preti, G.; Huggins, G. R. (1975-12-26). "Changes in the intensity and pleasantness of human vaginal odors during the menstrual cycle". Science. 190 (4221): 1316–1318. doi:10.1126/science.1239080. ISSN 0036-8075. PMID 1239080. 
  87. ^ Roberts, S. C.; Havlicek, J.; Flegr, J.; Hruskova, M.; Little, A. C.; Jones, B. C.; Perrett, D. I.; Petrie, M. (2004-08-07). "Female facial attractiveness increases during the fertile phase of the menstrual cycle". Proceedings of the Royal Society of London B: Biological Sciences. 271 (Suppl 5): S270–S272. doi:10.1098/rsbl.2004.0174. ISSN 0962-8452. PMID 15503991. 
  88. ^ Puts, David A.; Bailey, Drew H.; Cárdenas, Rodrigo A.; Burriss, Robert P.; Welling, Lisa L.M.; Wheatley, John R.; Dawood, Khytam. "Women's attractiveness changes with estradiol and progesterone across the ovulatory cycle". Hormones and Behavior. 63 (1): 13–19. doi:10.1016/j.yhbeh.2012.11.007. 
  89. ^ Bobst, Cora; Lobmaier, Janek S. "Men's preference for the ovulating female is triggered by subtle face shape differences". Hormones and Behavior. 62 (4): 413–417. doi:10.1016/j.yhbeh.2012.07.008. 
  90. ^ Scutt, D.; Manning, J.T. (1996-11-01). "Ovary and ovulation: Symmetry and ovulation in women". Human Reproduction. 11 (11): 2477–2480. doi:10.1093/oxfordjournals.humrep.a019142. ISSN 0268-1161. 
  91. ^ Bryant, Gregory A.; Haselton, Martie G. (2009-02-23). "Vocal cues of ovulation in human females". Biology Letters. 5 (1): 12–15. doi:10.1098/rsbl.2008.0507. ISSN 1744-9561. PMID 18845518. 
  92. ^ Pipitone, R. Nathan; Gallup, Gordon G. "Women's voice attractiveness varies across the menstrual cycle". Evolution and Human Behavior. 29 (4): 268–274. doi:10.1016/j.evolhumbehav.2008.02.001. 
  93. ^ Fales, Melissa R.; Gildersleeve, Kelly A.; Haselton, Martie G. "Exposure to perceived male rivals raises men's testosterone on fertile relative to nonfertile days of their partner's ovulatory cycle". Hormones and Behavior. 65 (5): 454–460. doi:10.1016/j.yhbeh.2014.04.002. 
  94. ^ Alvergne, Alexandra; Lummaa, Virpi. "Does the contraceptive pill alter mate choice in humans?". Trends in Ecology & Evolution. 25 (3): 171–179. doi:10.1016/j.tree.2009.08.003. 
  95. ^ Grøntvedt, Trond Viggo; Grebe, Nicholas M.; Kennair, Leif Edward Ottesen; Gangestad, Steven W. "Estrogenic and progestogenic effects of hormonal contraceptives in relation to sexual behavior: insights into extended sexuality". Evolution and Human Behavior. 38 (3): 283–292. doi:10.1016/j.evolhumbehav.2016.10.006. 
  96. ^ Thorpe., Ellison, Peter (2001). On fertile ground. Cambridge, MA: Harvard University Press. ISBN 9780674011120. OCLC 435534359. 
  97. ^ Roney, James R.; Simmons, Zachary L. "Women's estradiol predicts preference for facial cues of men's testosterone". Hormones and Behavior. 53 (1): 14–19. doi:10.1016/j.yhbeh.2007.09.008. 
  98. ^ Ellison, Peter Thorpe; Gray, Peter B. (2009). Endocrinology of Social Relationships. Harvard University Press. ISBN 9780674031173. 
  99. ^ Roney, James R.; Simmons, Zachary L. "Hormonal predictors of sexual motivation in natural menstrual cycles". Hormones and Behavior. 63 (4): 636–645. doi:10.1016/j.yhbeh.2013.02.013. 
  100. ^ Wood, Wendy; Carden, Lucas. "Elusiveness of menstrual cycle effects on mate preferences: Comment on Gildersleeve, Haselton, and Fales (2014)". Psychological Bulletin. 140 (5): 1265–1271. doi:10.1037/a0036722. 
  101. ^ Gildersleeve, Kelly; Haselton, Martie G.; Fales, Melissa R. "Meta-analyses and p-curves support robust cycle shifts in women's mate preferences: Reply to Wood and Carden (2014) and Harris, Pashler, and Mickes (2014)". Psychological Bulletin. 140 (5): 1272–1280. doi:10.1037/a0037714.