Changes in women's facial skin color over the ovulatory cycle are not detectable by the human visual system

PLoS ONE

Volumn 10, Issue 7, 2015, Pages

  Burriss, Robert P ^a   Troscianko, Jolyon ^b   Lovell, P George ^c,d   Fulford, Anthony J C ^e,f   Stevens, Martin ^b   Quigley, Rachael ^f   Payne, Jenny ^f   Saxton, Tamsin K ^a   Rowland, Hannah M ^f,g  

^a NORTHUMBRIA UNIVERSITY   (United Kingdom)

^b UNIVERSITY OF EXETER   (United Kingdom)

^c UNIVERSITY OF ABERTAY DUNDEE   (United Kingdom)

^d UNIVERSITY OF ST ANDREWS   (United Kingdom)

^e MEDICAL RESEARCH COUNCIL   (United Kingdom)

^f UNIVERSITY OF CAMBRIDGE   (United Kingdom)

^g INSTITUTE OF ZOOLOGY   (United Kingdom)

Author keywords

[No Author keywords available]

Indexed keywords

ADULT; ARTICLE; COLOR ANALYSIS; COMPARATIVE STUDY; CONTROLLED STUDY; CUTANEOUS PARAMETERS; DIGITAL IMAGING; FACIAL ATTRACTIVENESS; FACIAL SKIN COLOR CHANGE; FACIAL SKIN LUMINANCE; FEMALE; HUMAN; IMAGE ANALYSIS; JUST NOTICEABLE DIFFERENCE; LONG WAVE VISUAL RECEPTOR; LUTEAL PHASE; MEDIUM WAVE VISUAL RECEPTOR; MENSTRUAL CYCLE; MENSTRUAL ONSET; NORMAL HUMAN; PARAMETERS; PHOTOGRAPHY; PHOTORECEPTOR; PHYSICAL ATTRACTIVENESS; PREDICTION; SHORTWAVE VISUAL RECEPTOR; SKIN COLOR; SKIN REDNESS; VISUAL DISCRIMINATION; VISUAL SYSTEM; YOUNG ADULT; ADOLESCENT; ANATOMY AND HISTOLOGY; COLOR; ESTHETICS; FACE; FERTILITY; OVULATION; PATTERN RECOGNITION; PHYSIOLOGY; SEXUAL BEHAVIOR; VASCULARIZATION; VOICE;

ADOLESCENT; ADULT; BEAUTY; COLOR; FACE; FEMALE; FERTILITY; HUMANS; LUTEAL PHASE; OVULATION; PATTERN RECOGNITION, VISUAL; PHOTOGRAPHY; SEXUAL BEHAVIOR; VOICE;

EID: 84940567616     PISSN: None     EISSN: 19326203     Source Type: Journal    
DOI: 10.1371/journal.pone.0130093     Document Type: Article

References (113)

1. Deschner T, Heistermann M, Hodges K, Boesch C. Timing and probability of ovulation in relation to sex skin swelling in wild West African chimpanzees, Pan troglodytes verus. Anim Behav. 2003; 66 (551-560).
2. Higham JP, MacLarnon AM, Ross C, Heistermann M, Semple S. Baboon sexual swellings: Information content of size and color. Horm Behav. 2008; 53(3):452-62. Baboon sexual swellings: Information content of size and color. doi: 10.1016/j.yhbeh.2007.11.019 PMID: 18206889
3. Barelli C, Heistermann M, Boesch C, Reichard UH. Sexual swellings in wild white-handed gibbon females (Hylobates lar) indicate probablity of ovulation. Horm Behav. 2007; 51(2):221-30. doi: 10.1016/j.yhbeh.2006.10.008 PMID: 17137580
4. Higham JP, Brent LJN, Dubuc C, Accamando AK, Engelhardt A, Gerald MS, et al. Color signal information content and the eye of the beholder: a case study in the rhesus macaque. Behav Ecol. 2010; 21(4):739-46. doi: 10.1093/beheco/arq047 PMID: 22475874
5. Dubuc C, Brent LJN, Accamando AK, Gerald MS, MacLarnon A, Semple S, et al. Sexual skin color contains information about the timing of the fertile phase in free-ranging Macaca mulatta. Int J Primatol. 2009; 30(6):777-89. doi: 10.1007/s10764-009-9369-7
6. Fujita S, Sugiura H, Mitsunaga F, Shimizu K. Hormone profiles and reproductive characteristics in wilde female Japanese macaques (Macaca fuscata). Am J Primatol. 2004; 64(4):367-75. doi: 10.1002/ajp.20086 PMID: 15580584
7. Setchell J, Wickings EJ, Knapp LA. Signal content of red facial coloration in female mandrills (Mandrillus sphinx). Proc R Soc Lond B. 2006; 273(1599):2395-400. doi: 10.1098/rspb.2006.3573 PMID: 16928644
8. Hrdy SB, Whitten PL. Patterning of sexual activity. In: Smuts BS, Cheney DL, Seyfarth RM, Wrangham RW, Struhsaker TT, editors. Primate Societies. Chicago, IL: University of Chicago Press; 1987. p. 370-84.
9. Higham JP, Hughes KD, Brent LJN, Dubuc C, Engelhardt A, Heistermann M, et al. Familiarity affects the assessment of female facial signals of fertility by free-ranging male rhesus macaques. Proc R Soc Lond B. 2011; 278(1723):3452-8. doi: 10.1098/rspb.2011.0052 PMID: 21471112
10. Huchard E, Courtiol A, Benavides JA, Knapp LA, Raymond M, Cowlishaw G. Can fertility signals lead to quality signals? Insights from the evolution of primate sexual swellings. Proc R Soc Lond B. 2009; 276(1663):1889-97. doi: 10.1098/rspb.2008.1923 PMID: 19324772
11. Nunn CL. The evolution of exaggerated sexual swellings in primates and the graded-signal hypothesis. Anim Behav. 1999; 58(2):229-46. doi: 10.1006/anbe.1999.1159 PMID: 10458874
12. Gangestad SW, Thornhill R. Human oestrus. Proc R Soc Lond B. 2008; 275:991-1000. doi: 10.1098/rspb.2007.1425
13. Gildersleeve K, Haselton MG, Fales MR. Do women's mate preferences change across the ovulatory cycle? A meta-analytic review. Psychol Bull. 2014; 140(5):1205-59. doi: 10.1037/a0035438
14. Welling LLM, Puts DA. Female adaptations to ovulation. In: Weekes-Shackelford VA, Shackelford TK, editors. Evolutionary Perspectives on Human Sexual Psychology and Behavior. New York: Springer; 2014. p. 243-60.
15. Wood W, Kressel L, Joshi PD, Louie B. Meta-analysis of menstrual cycle effects on women's mate preferences Emot Rev. 2014; 6(3):229-49. doi: 10.1177/1754073914523073
16. Jones BC, DeBruine LM, Perrett DI, Little AC, Feinberg DR, Law Smith MJ. Effects of menstrual cycle phase on face preferences. Arch Sex Behav. 2008; 37(1):78-84. doi: 10.1007/s10508-007-9268-y PMID: 18193349
17. Little AC, Jones BC, Burriss RP. Preferences for masculinity in male bodies change across the menstrual cycle. Horm Behav. 2007; 51(5):633-9. doi: 10.1016/j.yhbeh.2007.03.006 PMID: 17466990
18. Cantú SM, Simpson JA, Griskevicius V, Weisberg YJ, Durante KM, Beal DJ. Fertile and selectively flirty: Women's behavior toward men changes across the ovulatory cycle. Psychol Sci. 2014; 25 (2):431-8. doi: 10.1177/0956797613508413 PMID: 24335600
19. Durante KM, Li NP, Haselton MG. Changes in women's choice of dress across the ovulatory cycle: naturalistic and laboratory task-based evidence. Pers Soc Psychol Bull. 2008; 34(11):1451-60. doi: 10.1177/0146167208323103 PMID: ISI:000259969000002.
20. Haselton MG, Mortezaie M, Pillsworth EG, Bleske-Rechek AL, Frederick DA. Ovulatory shifts in human female ornamentation: Near ovulation, women dress to impress. Horm Behav. 2007; 51 (1):40-5. doi: 10.1016/j.yhbeh.2006.07.007 PMID: 17045994
21. Beall AT, Tracy JL. Women more likely to wear red or pink at peak fertility. Psychol Sci. 2013; 24 (9):1837-41. doi: 10.1177/0956797613476045 PMID: 23842955
22. Thornhill R, Gangestad SW, Miller R, Scheyd G, McCollough JK, Franklin M. Major histocompatibility complex genes, symmetry, and body scent attractiveness in men and women (Homo sapiens). Behav Ecol. 2003; 14(5):668-78. PMID: ISI:000185596600011.
23. Havlíček J, Dvořáková R, Bartoš L, Flegr J. Non-advertized does not mean concealed: Body odour changes across the human menstrual cycle. Ethology. 2006; 112(1):81-90.
24. Kuukasjärvi S, Eriksson CJP, Koskela E, Mappes T, Nissinen K, Rantala MJ. Attractiveness of women's body odors over the menstrual cycle: the role of oral contraceptives and receiver sex. Behav Ecol. 2004; 15(4):579-84.
25. Pipitone RN, Gallup GG. Women's voice attractiveness varies across the menstrual cycle. Evol Hum Behav. 2008; 29(4):268-74. doi: 10.1016/j.evothumbehav.2008.02.001 PMID: ISI:000257025100006.
26. Bryant GA, Haselton MG. Vocal cues of ovulation in human females. Biol Lett. 2009; 5(1):12-5. doi: 10.1098/rsbl.2008.0507 PMID: ISI:000262596700004.
27. Puts DA, Bailey DH, Cárdenas RA, Burriss RP, Welling LLM, Wheatley JR, et al. Women's attractiveness changes with estradiol and progesterone across the ovulatory cycle. Horm Behav. 2013; 63 (1):13-9. doi: 10.1016/j.yhbeh.2012.11.007 PMID: 23159480
28. Haselton MG, Gildersleeve K. Can men detect ovulation? Curr Dir Psychol Sci. 2011; 20(2):87-92. doi: 10.1177/0963721411402668
29. Roberts SC, Havlíček J, Flegr J, Hruskova M, Little AC, Jones BC, et al. Female facial attractiveness increases during the fertile phase of the cycle. Proc R Soc Lond B (Suppl) Biol Lett. 2004; 271:S270-S2. doi: 10.1098/rsbl.2004.0174
30. Samson N, Fink B, Matts P. Does a woman's skin color indicate her fertility level? Preliminary findings. Swiss J Psychol. 2011; 70(4):199-202. doi: 10.1024/1421-0185/a000057
31. Bleske-Rechek A, Harris HD, Denkinger K, Webb RM, Erickson L, Nelson LA. Physical cues of ovulatory status: A failure to replicate enhanced facial attractiveness and reduced waist-to-hip ratio at high fertility. Evol Psychol. 2011; 9(3):336-53. PMID: 22947979
32. Bobst C, Lobmaier JS. Men's preference for the ovulating female is triggered by subtle face shape differences. Horm Behav. 2012; 62(4):413-7. doi: 10.1016/j.yhbeh.2012.07.008 PMID: 22846725
33. Oberzaucher E, Katina S, Schmehl SF, Holzleitner IJ, Mehu-Blantar I, Grammer K. The myth of hidden ovulation: Shape and texture changes in the face during the menstrual cycle. J Evol Psychol. 2012; 10(4):163-75. doi: 10.1556/JEP.10.2012.4.1
34. Bobst C, Lobmaier JS. Is preference for ovulatory female's faces associated with men's testosterone levels? Horm Behav. 2014; 66(3):487-92. doi: 10.1016/j.yhbeh.2014.06.015 PMID: 24975650
35. Mihm M, Gangooly S, Muttukrishna S. The normal menstrual cycle in women. Anim Reprod Sci. 2011; 124(3):229-36. doi: 10.1016/j.anireprosci.2010.08.030 PMID: 20869180
36. Law Smith MJ, Perrett DI, Jones BC, Cornwell RE, Moore FR, Feinberg DR, et al. Facial appearance is a cue to oestrogen levels in women. Proc R Soc Lond B. 2006; 273:135-40.
37. Probst F, Bobst C, Lobmaier JS. Testosterone-to-estradiol ratio is associated with female facial attractiveness. Q J Exp Psychol. in press. doi: 10.1080/17470218.2015.1024696
38. Guéguen N. Makeup and menstrual cycle: Near ovulation, women use more cosmetics. Psychol Rec. 2012; 62(3):541-8.
39. Thornton MJ. The biological action of estrogens on the skin. Exp Dermatol. 2002; 11(6):487-502. doi: 10.1034/j.1600-0625.2002.110601.x PMID: 12473056
40. Shah MG, Maibach HI. Estrogen and skin. Am J Clin Dermatol. 2001; 2(3):143-50. doi: 10.2165/ 00128071-200102030-00003 PMID: 11705091
41. Thornton MJ. Oestrogen functions in skin and skin appendages. Expert Opin Ther Targets. 2005; 9 (3):617-29. doi: 10.1517/14728222.9.3.617 PMID: 15948678
42. Pelletier G, Ren L. Localization of sex steroid receptors in human skin. Histol Histopathol. 2004; 19 (2):629-36. PMID: 15024720
43. Thornton MJ, Taylor AH, Mulligan K, Al-Azzawi F, Lyon CC, O'Driscoll J, et al. The distribution of estrogen receptor β is distinct to that of estrogen receptor α and the androgen receptor in human skin and the pilosebaceous unit. J Investig Dermatol Symp Proc. 2003; 8:100-3. doi: 10.1046/j.1523-1747.2003.12181.x PMID: 12895004
44. Yin JY, Fisher DE. Melanocyte biology and skin pigmentation. Nature. 2007; 445:843-50. doi: 10.1038/nature05660 PMID: 17314970
45. Brincat MP. Hormone replacement therapy and the skin. Maturitas. 2000; 35(2):107-17. PMID: 10924836
46. Charkoudian N, Stephens DP, Pirkle KC, Kosiba WA, Johnson JM. Influence of female reproductive hormones on local thermal control of skin blood flow. J Appl Physiol. 1999; 87(5):1719-23. PMID: 10562614
47. Liu D, Moberg E, Kollind M, Lins PE, Adamson U, Macdonald IA. Arterial, arterialized venous, venous and capillary blood glucose measurements in normal man during hyperinsulinaemic euglycaemia and hypoglycaemia. Diabetologia. 1992; 35(3):287-90. PMID: 1563586
48. Piérard GE. EEMCO guidance for the assessment of skin colour. J Eur Acad Dermatol Venereol. 1998; 10(1):1-11. doi: 10.1111/j.1468-3083.1998.tb00921.x PMID: 9552751
49. Zouboulis CC, Chen WC, Thornton MJ, Qin K, Rosenfield R. Sexual hormones in human skin. Horm Metab Res. 2007; 39(2):85-95. doi: 10.1055/s-2007-961807 PMID: 17326004
50. van den Berghe PL, Frost P. Skin color preference, sexual dimorphism and sexual selection: a case of gene-culture co-evolution? Ethn Racial Stud. 1986; 9(1):87-113.
51. McGuinness BW. Skin pigmentation and the menstrual cycle. Br Med J. 1961; 2:563-5. PMID: 13773989
52. Snell RS, Turner R. Skin pigmentation in relation to the menstrual cycle. J Investig Dermatol. 1966; 47 (2):147-55. doi: 10.1038/jid.1966.119 PMID: 5916127
53. Hahn AC, Whitehead RD, Albrecht M, Lefevre CE, Perrett DI. Hot or not? Thermal reactions to social contact. Biol Lett. 2012; 8(5):864-7. doi: 10.1098/rsbl.2012.0338 PMID: 22647931
54. Stevens M, Párraga CA, Cuthill IC, Partridge JC, Troscianko TS. Using digital photography to measure animal colouration. Biol J Linn Soc Lond. 2007; 90(2):211-37. doi: 10.1111/j.1095-8312.2007.00725.x
55. Jones BC, Hahn AC, Fisher CI, Wincenciak J, Kandrik M, Roberts SC, et al. Facial coloration tracks changes in women's estradiol. Psychoneuroendocrinology. 2015; 56:29-34. doi: 10.1016/j.psyneuen.2015.02.021 PMID: 25796069
56. Hong G, Luo MR, Rhodes PA. A study of digital camera colorimetric characterisation based on polynomial modeling. Color Res Appl. 2001; 26(1):76-84. doi: 10.1002/1520-6378(200102)26:1<76::AID-COL8>3.0.CO;2-3
57. Re DE, Whitehead RD, Xiao D, Perrett DI. Oxygenated-blood colour change thresholds for perceived facial redness, health, and attractiveness. PLoS One. 2011; 6(3):e17859. doi: 10.1371/journal.pone.0017859 PMID: 21448270
58. Stevens M, Stoddard MC, Higham JP. Studying primate color: towards visual system-dependent methods. Int J Primatol. 2009; 30:893-917. doi: 10.1007/s10764-009-9356-z
59. Párraga CA, Troscianko T, Tolhurst DJ. Spatiochromatic properties of natural images and human vision. Curr Biol. 2002; 12(6):483-7. PMID: 11909534
60. Harris CR, Chabot A, Mickes L. Shifts in methodology and theory in menstrual cycle research on attraction. Sex Roles. 2013; 69:525-35. doi: 10.1007/s11199-013-0302-3
61. Fernández JR, Hermida RC, Mojón A. Chronobiological analysis techniques. Application to blood pressure. Philos Trans A Math Phys Eng Sci. 2009; 367:431-45. doi: 10.1098/rsta.2008.0231 PMID: 18940774
62. Bliss CI. Periodic regression in biology and climatology. Bulletin of the Connecticut Agricultural Experiment Station, New Haven. 1958; 615:1-55.
63. Pisanski K, Hahn AC, Fisher CI, DeBruine LM, Feinberg DR, Jones BC. Changes in salivary estradiol predict changes in women's preferences for vocal masculinity. Horm Behav. 2014; 66(3):493-7. doi: 10.1016/j.yhbeh.2014.07.006 PMID: 25051294
64. Miller G, Tybur JM, Jordan BD. Ovulatory cycle effects on tip earnings by lap dancers: economic evidence for human estrus? Evol Hum Behav. 2007; 28:375-81. doi: 10.1016/j.evolhumbehav.2007.06.002
65. Puts DA. Cyclic variation in women's preferences for masculine traits: potential hormonal causes. Hum Nat. 2006; 17(1):114-27.
66. Direito A, Bailly S, Mariani A, Ecochard R. Relationships between the luteinizing hormone surge and other characteristics of the menstrual cycle in normally ovulating women. Fert Steril. 2013; 99(1):279-85. doi: 10.1016/j.fertnstert.2012.08.047 PMID: 22999798
67. Whitehead RD, Re D, Xiao D, Ozakinci G, Perrett DI. You are what you eat: within-subject increases in fruit and vegetable consumption confer beneficial skin-color changes. PLoS One. 2012; 7(3): e32988. doi: 10.1371/journal.pone.0032988 PMID: 22412966
68. Stewart DE. Positive changes in the pre-menstrual period. Acta Psychiatr Scand. 1989; 79:400-5. PMID: 2735211
69. Schneider CA, Rasband WS, Eliceiri KW. NIH Image to ImageJ: 25 years of image analysis. Nat Methods. 2012; 9:671-5. doi: 10.1038/nmeth.2089 PMID: 22930834
70. Jones BC, Little AC, Burt DM, Perrett DI. When facial attractiveness is only skin deep. Perception. 2004; 33(5):569-76. doi: 10.1068/p3463 PMID: 15250662
71. Stockman A, Sharpe LT. The spectral sensitivities of the middle-and long-wavelength-sensitive cones derived from measurements in observers of known genotype. Vision Res. 2000; 40(13):1711-37. PMID: 10814758
72. Stevens M, Cuthill IC. Disruptive coloration, crypsis and edge detection in early visual processing. Proc R Soc Lond B. 2006; 273(1598):2141-7. doi: 10.1098/rspb.2006.3556 PMID: 16901833
73. Stevens M, Lown AE, Wood LE. Color change and camouflage in juvenile shore crabs Carcinus maenas. Front Ecol Evol. 2014; 2(14). doi: 10.3389/fevo.2014.00014
74. R Core Team. R: A Language and Environment for Statistical Computing. Vienna, Austria: R Foundation for Statistical Computing; 2013. doi: 10.3758/s13428-013-0330-5 PMID: 23519455
75. Vorobyev M, Osorio D. Receptor noise as a determinant of colour thresholds. Proc R Soc Lond B. 1998; 265(1394):351-8. doi: 10.1098/rspb.1998.0302 PMID: 9523436
76. Hofer H, Carroll JS, Neitz J, Neitz M, Williams DR. Organization of the human trichromatic cone mosaic. J Neurosci. 2005; 25(42):9669-79. doi: 10.1523/JNEUROSCI.2414-05.2005 PMID: 16237171
77. Brainard DH. Color appearance and color difference specification. In: Shevell SK, editor. The Science of Color. Boston: Elsevier; 2003.
78. Cole LA, Ladner DG, Byrn FW. The normal variabilities of the menstrual cycle. Fert Steril. 2009; 91 (2):522-7. doi: 10.1016/j.fertnstert.2007.11.073 PMID: 18433748
79. Fehring RJ, Schneider M, Raviele K. Variability in the phases of the menstrual cycle. J Obstet Gynecol Neonatal Nurs. 2006; 35(3):376-84. doi: 10.1111/j.1552-6909.2006.00051.x PMID: 16700687
80. Bakos O, Lundkvist O, Wide L, Bergh T. Untrasonographical and hormonal description of the normal ovulatory cycle. Acta Obstet Gynecol Scand. 1994; 73(10):790-6. PMID: 7817731
81. Ecochard R, Gougeon A. Side of ovulation and cycle characteristics in normally fertile women. Hum Reprod. 2000; 15(4):752-5. doi: 10.1093/humrep/15.4.752 PMID: 10739814
82. Baird DD, McConnaughey R, Weinberg CR, Musey PI, Collins DC, Kesner JS, et al. Application of a method for estimating day of ovulation using urinary estrogen and progesterone metabolites. Epidemiol. 1995; 6:547-50.
83. Gangestad SW, Garver-Apgar CE, Simpson JA, Cousins AJ. Changes in women's mate preferences across the cycle. J Pers Soc Psychol. 2007; 92(1):151-63. doi: 10.1037/0022-3514.92.1.151 PMID: 17201549
84. Gangestad SW, Thornhill R. Menstrual cycle variation in women's preferences for the scent of symmetrical men. Proc R Soc Lond B. 1998; 265(1399):927-33. doi: 10.1098/rspb.1998.0380 PMID: 9633114
85. Thornhill R, Gangestad SW. The scent of symmetry: A human sex pheromone that signals fitness? Evol Hum Behav. 1999; 20(3):175-201. PMID: ISI:000081505200005.
86. Wilcox AJ, Dunson DB, Weinberg CR, Trussell J, Baird DD. Likelihood of conception with a single act of intercourse: providing benchmark rates for assessment of post-coital contraceptives. Contraception. 2001; 63(4):211-5. doi: 10.1016/S0010-7824(01)00191-3 PMID: 11376648
87. StataCorp. Stata Statistical Software (Release 12). College Station, TX: StataCorp LP; 2011.
88. Nelson W, Tong YL, Lee JK, Halberg F. Methods for cosinor-rhythmometry. Chronobiologia. 1979; 6 (4):305-23. PMID: 548245
89. Cox NJ. Speaking Stata: In praise of trigonometric predictors. Stata J. 2006; 6(4):561-79.
90. Fulford AJC. The coefficient of cyclic variation: a novel statistic to measure the magnitude of cyclic variation. Emerg Themes Epidemiol. 2014; 11:15. doi: 10.1186/1742-7622-11-15 PMID: 25342954
91. Stirnemann JJ, Samson A, Bernard J-P, Thalabard J-C. Day-specific probabilities of conception in fertile cycles resulting in spontaneous pregnancies. Hum Reprod. 2013; 28(4):1110-6. doi: 10.1093/humrep/des449 PMID: 23340057
92. Tan KW, Stephen ID. Colour detection thresholds in faces and colour patches. Perception. 2013; 42 (7):733-41. doi: 10.1068/p7499 PMID: 24344549
93. Fink B, Grammer K, Matts PJ. Visible skin color distribution plays a role in the perception of age, attractiveness, and health in female faces. Evol Hum Behav. 2006; 27:433-42. doi: 10.1016/j.evolhumbehav.2006.08.007
94. Lefevre CE, Ewbank MP, Calder AJ, von dem Hagen E, Perrett DI. It is all in the face: carotenoid skin coloration loses attractiveness outside the face. Biol Lett. 2013; 9(6):20130633. doi: 10.1098/rsbl.2013.0633 PMID: 24307526
95. Lefevre CE, Perrett DI. Fruit over sunbed: Carotenoid skin coloration is found more attractive than melanin coloration. Q J Exp Psychol. 2015; 68(2):284-93. doi: 10.1080/17470218.2014.944194 PMID: 25014019
96. Stephen ID, Coetzee V, Law Smith M, Perrett DI. Skin blood perfusion and oxygenation colour affect perceived human health. PLoS One. 2009; 4(4):e5083. doi: 10.1371/journal.pone.0005083 PMID: 19337378
97. Alliende ME. Mean versus individual hormonal profiles in the menstrual cycle. Fert Steril. 2002; 78 (1):90-5. PMID: 12095496
98. Cobey KD, Buunk AP, Pollet TV, Klipping C, Roberts SC. Men perceive their female partners, and themselves, as more attractive around ovulation. Biol Psychol. 2013; 94(3):513-6. doi: 10.1016/j. biopsycho.2013.09.011 PMID: 24096241
99. Sillen-Tullberg B, Moller AP. The relationship between concealed ovulation and mating systems in anthropoid primates: A phylogenetic analysis. Am Nat. 1993; 141(1):1-25. doi: 10.1086/285458 PMID: 19426020
100. Pawłowski B. Loss of oestrus and concealed ovulation in human evolution: the case against the sexual-selection hypothesis. Curr Anthropol. 1999; 40(3):257-75.
101. Pagel M, Meade A. Bayesian analysis of correlated evolution of discrete characters by reversiblejump Markov chain Monte Carlo. Am Nat. 2006; 167(6):808-25. doi: 10.1086/503444 PMID: 16685633
102. Duda P, Zrzavý J. Evolution of life history and behavior in Hominidae: Towards phylogenetic reconstruction of the chimpanzee-human last common ancestor. J Hum Evol. 2013; 65:424-46. doi: 10.1016/j.jhevol.2013.07.009 PMID: 23981863
103. Leongómez JD, Binter J, Kubicová L, Stolaøová P, Klapilová K, Havlíček J, et al. Vocal modulation during courtship increases proceptivity even in naive listeners. Evol Hum Behav. 2015; 35(6):489-96. doi: 10.1016/j.evolhumbehav.2014.06.008
104. Campbell BG. Human Evolution. 2nd ed. Chicago: Aldine; 1974.
105. Tombs S, Silverman I. Pupillometry: A sexual selection approach. Evol Hum Behav. 2004; 25(4):221-8.
106. Laeng B, Falkenberg L. Women's pupillary responses to sexually significant others during the hormonal cycle. Horm Behav. 2007; 52(4):520-30. doi: 10.1016/j.yhbeh.2007.07.013 PMID: 17870074
107. Changizi MA, Zhang Q, Shimojo S. Bare skin, blood and the evolution of primate colour vision. Biol Lett. 2006; 2(2):217-21. doi: 10.1098/rsbl.2006.0440 PMID: 17148366
108. Marsh EE, Shaw ND, Kingman KM, Tiamfook-Morgan TO, Yiamalas MA, Sluss PM, et al. Estrogen levels are higher across the menstrual cycle in African-American women compared with Caucasian women. J Clin Endocrinol Metab. 2011; 96(10):3199-206. doi: 10.1210/jc.2011-1314 PMID: 21849524
109. Roney JR, Simmons ZL. Women's estradiol predicts preference for facial cues of men's testosterone. Horm Behav. 2008; 53:14-9. PMID: 17950291
110. Roney JR, Simmons LW, Gray PB. Changes in estradiol predict within-women shifts in attraction to facial cues of men's testosterone. Psychoneuroendocrinology. 2011; 36(5):742-9. doi: 10.1016/j. psyneuen.2010.10.010 PMID: 21067866
111. Coetzee V, Greeff JM, Stephen ID, Perrett DI. Cross-cultural agreement in facial attractiveness preferences: The role of ethnicity and gender. PLoS One. 2014; 9(7):e99629. doi: 10.1371/journal.pone. 0099629 PMID: 24988325
112. Baird DT, Fraser IS. Blood production and ovarian secretion rates of estradiol-17β and estrone in women throughout the menstrual cycle. J Clin Endocrinol Metab. 1974; 38(6):1009-17. doi: 10.1210/ jcem-38-6-1009 PMID: 4598662
113. Buxton CL, Atkinson WB. Hormonal factors involved in the regulation of basal body temperature during the menstrual cycle and pregnancy. J Clin Endocrinol Metab. 1948; 8(7):544-9. doi: 10.1210/ jcem-8-7-544 PMID: 18869601