Thanks for another interesting discussion of the state of the research. It seems to me that a useful way to think about estrus in humans is in terms of sexual receptivity, as opposed to fertility. The human female is able and willing (theoretically, at least) to have sex at any point in her menstrual cycle. One can also argue, as many do, that women's pendulous breasts are permanent sexual swellings. So maybe women didn't "lose" estrus, so much as expand it (or at least behavioral and visual cues to it) to occupy their whole menstrual cycle.

I'm not sure that the statement that estrogen levels peak at ovulation is true - progesterone is released at time of ovulation - which functions to drop levels of estrogen during the time women are most fertile. It would be more accurate, perhaps, to say that estrogen levels peak just before ovulation.

The concept presented would be very interesting in the context of the wide-spread use of oral contraceptives in women (in our study, over 80% had used hormonal contraceptives at one time or another - and many for "non-contraceptive benefits of the pill" which is also prescribed for everything from acne to heavy bleeding). Would sustained levels of high ovarian hormones be more or less "attractive" for males and how would different formulations interfere with this silent chemical attraction?

So let me get this straight, if i'm loaded I get all the women? Seems that Scarfarce was right. '' First you get the money, then you get the power, then you get thee woooommmmenn''.

Woww what an interesting article! It's almost inspired me to take a course is psychology.

I find it interesting that the author forgot to mention the issue of hormonal contraception. The mass majority of women are taking hormonal contraception which would confuse her body hormonally, and I am sure would effect how fertile she is, and the signals etc that she gives off when she is fertile.

I am a natural woman, dont take any hormonal contraception and stay aware from anything that could disrupt my hormones (smokeing, drinking etc). I have been like this for two years now, and have become accutely aware of when I am most fertile.

My skin does become paler, and my skin pores become smaller, skin looks for radiant and young, eyes seem to appear bigger. Genrelly I feel more energetic, labido is higher aswell.

I have also become aware of how men behave around me when I am fertile, I seem to get more male attention in an almost competitive way, and my partner seems to be more sexually attracted to me and posessive. One of my work collegues even commented on how lovely I smelt, I dont wear perfume or anything that disguises my natural smell.

I realise this makes me sound ridiculously big headed, bu I assure you, the other 3 weeks of my cycle, I battle with pimples, blemishes, periods, and other such burdens. So I have learnt to really value this one week of fertility I have. And it's so thrilling to be completley intune with my body.

I think these days we live in a sexless society, where women are taking dodgy hormonal contraception and men are drinking/smokeing and genrelly not looking after there health. Being fertile should be encouraged, it encourages people to be healthy and thus have healthy offspring.