# Intensity of Body Odors and the MHC: Should We Expect a Link?

**URL:** <https://pheromonetalk.com/t/intensity-of-body-odors-and-the-mhc-should-we-expect-a-link/553>\
**Category:** Studies & Abstracts\
**Created:** [August 5, 2006, 2:39pm UTC](https://pheromonetalk.com/t/intensity-of-body-odors-and-the-mhc-should-we-expect-a-link/553 "2006-08-05T14:39:32Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![PheroQuirk](https://avatars.discourse-cdn.com/v4/letter/p/9e8a1a/32.png) [@PheroQuirk](https://pheromonetalk.com/u/PheroQuirk)\
**Post date:** [August 5, 2006, 2:39pm UTC](https://pheromonetalk.com/t/intensity-of-body-odors-and-the-mhc-should-we-expect-a-link/553/1 "2006-08-05T14:39:32Z")

</div>

> **[Publications | Human Nature](https://human-nature.com/publications/)**
>
> A List of Publications by Human Nature on The Mind Body Problems of Humans Why Humans Put on Weight and Get Fat There are a variety of reasons why humans put on weight and get fat. One reason is simply due to overeating. When we consume more calories...

---

<div class="post-metadata">

**Author:** ![MarkL](https://sea2.discourse-cdn.com/flex016/user_avatar/pheromonetalk.com/markl/32/825_2.png) [@MarkL](https://pheromonetalk.com/u/MarkL)\
**Post date:** [December 2, 2006, 10:51am UTC](https://pheromonetalk.com/t/intensity-of-body-odors-and-the-mhc-should-we-expect-a-link/553/2 "2006-12-02T10:51:09Z")

</div>

What I got was this:

- Females ordinarily prefer the scent of sweat of males with a differing set of antigens

- Everyone has the same half-dozen or so kinds of antigens (humans, anyway)

- There are up to 300 “styles” for each of the antigens (genetic alleles)

- Humans which had matching “styles” on several alleles (same “style” of antigen inherited from both mother and from father = “homozygous”)

1. Were, in general, found to be less physically attractive (face)

2. Were found to have stronger, more offensive sweat odor

3. Stronger sweat odor might be perceived because the odor is more offensive - or - more offensive sweat odor might be perceived because the odor is stronger. (Can’t be sure which way it runs, or if it runs both ways.)

4. Females on birth control pills **lose** their sensitivity to whether or not males have a different set of antigens (in odor of sweat tests).

5. Females who are pregnant are more sensitive to odors.  
So, it seems that “smelling right” is more important than “having the right smell” based on this research: that having a compatible odor (non-matching antigen set) is more valued than having some particular “right stuff” odor (one of a particular group of high-value antigen sets.)

This is a pretty complex piece of research. One **simple outcome** for me is that if I get a really strong aversive reaction from a woman, it may simply be that she is pregnant, and therefore highly reactive; the other is that _**women on birth control may, as a group, respond differently to [pheromones](https://a314.com/shop/), as well as odors…**_

---

<div class="post-metadata">

**Author:** ![PheroQuirk](https://avatars.discourse-cdn.com/v4/letter/p/9e8a1a/32.png) [@PheroQuirk](https://pheromonetalk.com/u/PheroQuirk)\
**Post date:** [December 2, 2006, 12:09pm UTC](https://pheromonetalk.com/t/intensity-of-body-odors-and-the-mhc-should-we-expect-a-link/553/3 "2006-12-02T12:09:26Z")

</div>

> [@MarkL](#):
>
> - Females on birth control pills **lose** their sensitivity to whether or not males have a different set of antigens (in odor of sweat tests).
> - Females who are pregnant are more sensitive to odors.

Nice summary. I thought though from what I have read elsewhere that women on the pill are like pregnant women - they prefer the company of men with similar MHC complexes. This raises potentially interesting issues when a couple get together and the woman is on the pill at the time but subsequently goes off it. (Both with regards to the emotional sense of compatibility and also perhaps to potentially weaker immune status for their children).

> [@](#):
>
> So, it seems that “smelling right” is more important than “having the right smell” based on this research: that having a compatible odor (non-matching antigen set) is more valued than having some particular “right stuff” odor (one of a particular group of high-value antigen sets.)

Aren’t they like two different dimensions, both of which matter? None and rone (and all the other fun toys we use here) signal things like social status, immune system strength, dominance/aggressiveness, capacity to act as a father whereas MHC signals genetic compatibility.

> [@](#):
>
> One **simple outcome** for me is that if I get a really strong aversive reaction from a woman, it may simply be that she is pregnant, and therefore highly reactive; the other is that _ **women on birth control may, as a group, respond differently to pheromones, as well as odors…** _

Yes, agreed. But is strong aversion overstating it? I mean she just might not find you her type…

---

<div class="post-metadata">

**Author:** ![MarkL](https://sea2.discourse-cdn.com/flex016/user_avatar/pheromonetalk.com/markl/32/825_2.png) [@MarkL](https://pheromonetalk.com/u/MarkL)\
**Post date:** [December 2, 2006, 6:50pm UTC](https://pheromonetalk.com/t/intensity-of-body-odors-and-the-mhc-should-we-expect-a-link/553/4 "2006-12-02T18:50:43Z")

</div>

> [@](#):
>
> Nice summary. I thought though from what I have read elsewhere that women on the pill are like pregnant women - they prefer the company of men with similar MHC complexes. This raises potentially interesting issues when a couple get together and the woman is on the pill at the time but subsequently goes off it. (Both with regards to the emotional sense of compatibility and also perhaps to potentially weaker immune status for their children).

Yes! I speculated on that possibility – and it wasn’t idle speculation in my case. My wife and I met while she was on BC. Later, when she stopped BC we did a couple of years of the medical (in)fertility dance until we found a doc who told us “I know what the problem is, and I can fix it.” The problem: our immune system phenotypes were too similar, so much so that when pregnant, her body interpreted the presence of a foetus as a tumor (‘self’ tissue) instead of as another being.

I don’t know what the implications are for the health of my sons’ immune systems, but I plan to make a call on Monday. (Note: they don’t look unattractive, but I am biased, 🙂)

> [@](#):
>
> Aren’t they like two different dimensions, both of which matter? None and Androsterone (and all the other fun toys we use here) signal things like social status, immune system strength, dominance/aggressiveness, capacity to act as a father whereas MHC signals genetic compatibility.

I don’t disagree. I would speculate (based on the hypothesized principle of safely maximizing diversity in all things reproductive) that attraction functions should ~not~ be stable or linear, but should be dynamic and chaotic in the best “butterfly effect” sense – so that for any given female on any given Sunday, the -nonal or -ronal or MHC signals (or factor X or Y or …) might tip the scale.

> [@](#):
>
> Yes, agreed. But is strong aversion overstating it? I mean she just might not find you her type…

The example in the paper mentioned the case of the pregnant woman who felt nauseated / ill for hours. That’s the kind of strong aversion I was thinking of …😃
