Question Peri.d 4: Do hormones affect our sense of smell? Mate selection? Reproduction?

Do you ever notice that your partner’s sweaty t-shirt smells delish to you when you’re ovulating but maybe more on the "sleep in the guest-room please?" side of things, during PMS or your luteal phase?

Do you ever notice that you receive more attention around ovulation and are told you smell good?

This is because hormone changes throughout the monthly cycle, can affect how we smell to others and how we perceive scent. 

Depending on which hormone(s) is dominating a specific phase of our cycle, our body odour smells differently and our scent perception, can also change with it.This is actually closely tied to our survival, because scent plays a crucial role in mate selection, sexual attraction and reproduction. 

In what’s now famously referred to as the ‘sweaty t-shirt experiment’ scientist Claus Wedekind of the Zoological Institute in Bern, Switzerland, did a study to test his hypothesis, that scent plays a crucial role in mate selection. His lab asked 121 men and women to score the odours of six  t-shirts , worn by two women and four men. Their scorings of pleasantness correlated negatively with the degree of MHC similarity between smeller and T-shirt-wearer in men and women who were not using the contraceptive pill (but not in Pill-users).

In laywoman’s terms, this means that his study found that a closer a person’s immune system or major histocompatibility complexe (MHC)- is to your own, the less likely you will find their natural scent attractive.

This is likely an evolution to guarantee offspring’s stronger immunity but also to avoid inbreeding/ a.k.a incest. Though many of us don’t really give our sense of smell a second thought, it is closely tied to our survival- smelling fire or smoke, can alert us to danger, detecting the scent of rotten food can too! Smelling our partner’s neck can also alert us to danger but the good kind, hopefully!

Scent is so important to our survival, that it is the first and only sense of our five senses, to be  fully developed in utero- in the womb. A newborn and mother can mutually recognize each other by scent within the first 30 minutes after a baby is born!

Paying attention to how we perceive scent and our own body odour and how sharply we can smell it at different times of the month, as well as different potential partner's unique body odour (sans colognes or deodorants etc), can give us a lot of important information with respect to our fitness and theirs, both in general and as potential romantic partners. Definitely something to pay attention to!

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