Hey Head Squeezers, I hope you're well.
This question comes in from Kevin Sheppard from our G plus community, who asks-- 'The
armpit, what's it for and why is it hairy?'
Great question Kevin.
Now I was thinking of calling this one 'how the smell of your sweat helps you score',
or not.
In this video I'm going to uncover whether or not you should eat red meat, and whether
or not that makes you more attractive to the opposite sex or not, and the definitive answer
from the world of science -- who has the most potent BO, men or women.
That's all coming up.
First things first, though.
There are a whole load of theories as to why we have hairy pits...
Theory number one says it's actually to wick the sweat away from the underarm so that you
prevent the lymph nodes from over-heating.
Theory number two says it's too lower down the friction, reduce the friction when you
walk between your upper arm and your thorax.
The third theory, and the one that I want to explore is all about sweating, and releasing
sex pheromones.
Now, not to go all Sherlock on you, but you are giving out a lot of information to the
outside world.
Now I'm not talking about a particular type of mud on your shoe, or spotting a particular
hair on your jacket.
No, I'm talking about your smell.
And while I'm at it, let's uncover why that smell is produced.
It's kind of icky.
It's all about the by-products of microbial fermentation in your body's damp creases.
In other words, you have bacteria living in there that are feeding off your nutrient rich
secretions, and it is their waste that creates that smell.
Gross.
James May did a fantastic film last year all about smell, and about how deodorant works,
so we'll put a link up to that after this film.
So, next question, what does your sweat say about you?
Well, recent research suggests that sweat says a whole load of things about an individuals'
status within a group, about their gender, about their reproductive state... in hyenas.
But heh, hyenas are mammals.
We're mammals....
No, there is a lot of research that has been done on humans as well that suggests that
the underarm smell does have a big role in attracting and keeping a partner.
Think about it, you're in a club, you're strutting your stuff, someone comes up close to you,
you think "yeah, they're pretty fine."
But then you get a waft and it's all a bit of a turn off.
Yeah.
But it's a lot deeper than that.
Actually, subconsciously, you may be attracted or not attracted to their smell
Now, I'm not talking about Chanel or CK, I am talking about Eau de armpit.
More specifically, I'm talking about your major histocompatibility complex or MHC -- it's
a bunch of genes that are important and are linked to not only your smell but your immune
system.
There was a brilliant experiment done by a scientist called Claus Wedekind what hed did
was he asked some guys to wear the same t-shirt for a few days.
He then gave these smelly t-shirts to a bunch of ladies, and asked them to choose a partner
based purely on the smell of those t-shirts.
They found the t-shirts most pleasant from guys who had very different MHCs to them.
Why is that the case?
Well, it's really good because it shows they've got very different genes.
So not only would it stop incest -- that was one thing they thought -- it would also mean
that if they did partner up and have a kid they would have a combination of those two
different types of genes, different types of immune systems and they'd have the strongest
immune system that they could.
Wedekind C, Seebeck T, Bettens F, and Paepke A.
MHC-Dependent Mate Preferences in Humans Proc. R. Soc.
Lond.
B 22 June 1995 vol. 260 no.
1359 245-249 http://rspb.royalsocietypublishing.org/content/260/1359/245.abstract
So there's clearly a whole bunch of different chemicals in play here, and the last one I
want to tell you about is androstadienone -- it's a steroid, a natural by-product of
testosterone
Now, researchers at Liverpool University set up a very interesting speed dating event.
They gave a portion of the women some of that androstadienone underneath their nostrils,
and the other portion didn't have that at all, they just had a placebo that smelt the
same.
And they found that the ones that were under the influence of that chemical rated all the
men as a lot more attractive than the ones that weren't.
Saxton T, Lyndon A, Little A, Roberts C. Evidence that androstadienone, a putative
human chemosignal, modulates women's attributions of men's attractiveness.
Hormones and behavior 2008; 54(5): 597-601 http://www.ncbi.nlm.nih.gov/pubmed/18601928
There you go, sex pheremones are very very important, and the idea that hairy pits can
help release these sex pheremones out and have a very big impact on mate choice.
So, time for the big question.
Who has the smelliest BO -- men or women?
Well, the research was done by the Monell Chemical Senses Center, and they found...it
was men.
Sorry guys.
And, And, bonus fact for you, women apparently prefer the "odor signatures" from men who
are on a non-meat diet.
Havlicek J, Lenochova P.
The effect of meat consumption on body odor attractiveness.
Chem Senses. 2006 Oct;31(8):747-52.
Epub 2006 Aug 4.
http://www.ncbi.nlm.nih.gov/pubmed/16891352
So, our advice, best lay off that steak before a night out!
That's pretty much it from me.
If you do have any burning questions you want to ask Head Squeeze all you have to do is
put them in the comments below this video or even better join up to our G plus community
page, allo the details in the description below.
Until next time, Happy Head Squeezing!