Fertility cues make women more attractive — maybe it's the voice, or the hip-to-waist ratio, or symmetry, or ...

Studies of tips earned by lap dancers indicate men are more attracted to women who are ovulating, i.e. most fertile.

http://www.abc.net.au/science/articles/2012/07/03/3537847.htm#.Ub-XNP1hiSM

http://www.nytimes.com/2007/12/09/magazine/09lapdance.html?_r=0 / ovulate ovulation ovulating majority men  pretty subtle subset sensitive gentlemen gentlemen's clubs dimly lit serve alcohol play music loudly male clients 20 and 60 years age evening $20 bills club's ATM relax relaxing drinkies drink drinks wear very little perfume shaved all over many have breast implants heavy physical demands lap dancing aerobic resistance weight training fit lean 18 lap dancers Albuquerque New Mexico volunteered paid only $30 volunteering. Two 2 month two-month course study performed 296 shifts five hours long 5,300 lap dances Seven taking oral contraceptive pill 11 normal menstrual cycles average age 27 years lapdancing six years dance dancing dancer paid salary club only income tips earn their money they appear  more sexually attractive than the other rival dancers working the same shift and by doing the emotional labour counterfeiting intimacy with male club patrons perform a few stage dances every 90 minutes advertise themselves small tips one to five dollars usually only from the men seated closest to the stage 10 per cent of their earnings advertise advertised advertising presence attractiveness availability lap dancer walking around asking the men  wanted lap dance real money three minute three-minute lap dances normal menstrual cycles ovulated earned more money the pill results showed clear difference within or across the menstrual cycle lap dancer was menstruating per shift not fertile infertile either she earned more fertile part of the menstrual cycle ovulating she earned the greatest sum of money separate study women woman woman's voice her fertility Dr. Dr Pipitone colleagues recorded 51 women reading numbers one and 10 four during menstrual cycle peak fertility time at ovulation record recordings rated 34 men 32 women attractiveness attractive change in attractiveness over the month taking hormonal contraceptives the pill definite peak attractiveness women at their most fertile ovulation female larynx voice box influenced by female sex hormones studies claim around ovulation women show definite increase verbal fluency creativity  facial attractiveness soft tissue body symmetry waist-to-hip ratio shrinks slimmer more attractive waist combined child-bearing hips stimulate a man's deep instincts father children Ovulating women are also supposed to smell more attractive evidence human mate guarding mate-guarding behaviour harem lionesses most fertile ring her more often random times technically described higher proprietariness attentiveness and vigilance /