here's an excerpt from a medical study that confirms women have superior olfactory senses. the interesting part is that SINCE we know women can detect "minute differences in male immunotype" THAN WE CAN INTELLIGENTLY infer woman are going to be able to detect the SOUR ASS odor that TOFTT has been describing.
IF YOU STINK, SO WILL YOUR SESSION WITH A SP. further, you are not going to be hooking up in the real world either.
Smell and hormones
Women, particularly women of reproductive age, have a more acute sense of smell than men. The smell sensitivity of most women varies across the menstrual cycle, peaking at ovulation (approx. day 14 of cycle where the beginning of menstruation is day 0). This peak in smell sensitivity coincides with a surge in plasma estradiol (an oestrogen). Estradiol also increases during pregnancy, perhaps explaining why some women report an increase in smell (and taste) sensitivity during pregnancy.
Smell declines with age but postmenopausal decreases in smell sensitivity are not reversed by hormone replacement therapy (HRT)1.
In Kallmann's syndrome there is an impaired sense of smell. Affected individuals have deficient gonadotropin levels (hormones that stimulate the function of the testes and the ovaries). Recent studies demonstrate that GnRH neurons originate in olfactory tissues and migrate to the hypothalamus but fail to do so in Kallman's syndrome. In addition the olfactory bulbs fail to develop.
1Hughes et al. Climacteric. 2002 Jun;5(2):140-50
Smell and ageing
As we get old our sense of smell declines. This also affects our sense of taste and food will lose its flavour. By 80 years old 80% of people have some major smell dysfunction and 50% are "anosmic" by the standards of young people. Not only do we lose our sense of smell, we lose our ability to discriminate between smells.[
SIZE=7]Women, while also losing smell sensitivity with age, perform better than men at all ages[/SIZE]. Patients with neurodegenerative diseases, such as Alzheimer's disease, suffer olfactory losses. Very early stage Alzheimer's patients show a loss of smell sensitivity.
Smell and mate choice
Recent work from Martha McClintock's lab in Chicago shows that women are able to detect minute differences in male immunotype by smell (Jacob et al., 2002). Immunotype is conferred by HLA alleles, the genes that confer immunity in humans (the equivalent of MHC in animals), and determines our individual smell. We tend to prefer smell of people who have different HLA alleles to our own. This would mean the offspring of such a match would confer immune advantage - more different HLA alleles would be passed on to the kids giving them a greater degree of immunity. We tend to be repelled by people whose immunotype (HLA alleles) is similar to our own. It looks like we choose our partner on the basis of smell (Wedekind et al., 1997) - well it would be one factor anyway. So, why do we spend so much time, and money, disguising it? Actually, we can probably detect the HLA-related smell in spite of our best attempts to cover it up!
Interestingly, the Chicago lab found that the women in their study rated human odour in absolute terms as slightly pleasant and more pleasant than common household odours (0.2 on a scale -5 to +5).
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Body odour
Why do we smell? What makes us smell different?
Our apocrine glands, situated in our axillae (armpits), sternum (centre chest), groin, nipples, cheeks, eyelids, ear, and scalp, secrete compounds that are virtually odorless. They become smelly by the action of bacteria - particularly those living in our armpits (yuk!).
There are three theories currently to explain why we all have a unique smell:
1. The HLA molecules (see above) themselves (which confer "self" and are unique to each individual) might confer an individual smell. Although they are not very volatile.
2. HLA molecules may influence odour by binding unique subsets of peptides, which are secreted and acted on by the bacteria on our skin (e.g. armpits) to make them volatile. These volatile compounds are our smell.
3. The HLA genes may influence the specific populations of bacteria living in our axillae. Different bacteria would then metabolise our secretions in different ways to make different smells.
