The Pill Makes Women Pick Bad Mates

[belgareth]

The Pill Makes Women Pick Bad Mates


Jeanna

Bryner
Senior

Writer
LiveScience.comTue Aug 12, 8:21 PM ET




Birth-control pills could screw up a woman's ability to sniff out a compatible mate, a new study finds.



While several factors can send a woman swooning, including big brains and brawn, body odor can be critical in

the final decision, the researchers say. That's because beneath a woman's flowery fragrance or a guy's musk the

body sends out aromatic molecules that indicate genetic compatibility.

Major histocompatibility complex (MHC)

genes are involved in immune response and other functions, and the best mates are those that have different MHC

smells than you. The new study reveals, however, that when women are on the pill they prefer guys with matching MHC

odors.

MHC genes churn out substances that tell the body whether a cell is a native or an invader. When

individuals with different MHC genes mate, their offspring's immune systems can recognize a broader range of

foreign cells, making them more fit.

Past studies have suggested couples with dissimilar MHC genes are more

satisfied and more likely to be faithful to a mate. And the opposite is also true with matchng-MHC couples showing

less satisfaction and more wandering eyes.

"Not only could MHC-similarity in couples lead to fertility

problems," said lead researcher Stewart Craig Roberts, an evolutionary psychologist at the University of Newcastle

in England, "but it could ultimately lead to the breakdown of relationships when women stop using the contraceptive

pill, as odor perception plays a significant role in maintaining attraction to partners."

Sexy scents

The

study involved about 100 women, aged 18 to 35, who chose which of six male body-odor samples they preferred. They

were tested at the start of the study when none of the participants were taking contraceptive pills and three months

later after 40 of the women had started taking the pill more than two months prior.

For the non-pill users,

results didn't show a significant preference for similar or dissimilar MHC odors. When women started taking birth

control, their odor preferences changed. These women were much more likely than non-pill users to prefer MHC-similar

odors.

"The results showed that the preferences of women who began using the contraceptive pill shifted towards

men with genetically similar odors," Roberts said.

Pregnant state

Based on the work by Claus Wedekind, a

University of Lausanne researcher who preformed similar studies in the 1990s, Roberts suggests a likely reason for

the pill's effect on a woman's odor preferences. The pill puts a woman's body into a hormonally pregnant state

(the reason she doesn't ovulate), and during that time there would be no reason to seek out a mate.

"When women

are pregnant there's no selection pressure, evolutionarily speaking, for having a preference for genetically

dissimilar odors," Roberts said. "And if there is any pressure at all it would be towards relatives, who would be

more genetically similar, because the relatives would help those individuals rear the baby."

So the pill puts a

woman's body into a post-mating state, even though she might be still in the game.

"The pill is in effect

mirroring a natural shift but at an inappropriate time," Roberts told LiveScience.

The results are detailed in

the current issue of the journal Proceedings of the Royal Society B: Biological Sciences.
Video: Sex and the

Senses 10 Things You Didn't Know About You The Sex Quiz: Myths, Taboos and Bizarre Facts Original Story: The Pill

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[Pagodeiro]

I always instictly knew

that....

Pago

[DrSmellThis]

By the same token, this

creates opportunities for those totally inappropriate "bad boys".

If you date a woman who is pregnant or on

the pill, you just have to realize you are probably getting into something time limited.

You also have to know

that if you "let" your girlfriend or wife get on the pill, you are exposing your relationship to possible stress,

especially in the sexuality department. And it helps explain why pregnancy is often a difficult time for

couples.

This all certainly fits my personal experience, in both cases.

Every woman and man should be taught

this.

Nice post, Bel. We've known this for a number of years, but it's nice to see another study supporting the

conclusion.

[koolking1]

I read about this on

another site (nothing at all related, a financial advisor type who comments about lots of things) and I though to

myself, Love-Scenters have known about this for years.

Isn't it kind of ironic that pheromone wearers are

running the same risk, attracting someone who ordinarily wouldn't be interested in us.

I don't recall it

ever mentioned here, guy wears mones and attracts gal, stops wearing them and she heads out the door, has it

happened to anyone?

Speaking of birth control pills, I got an email today from a female acquaintance who is

telling me that the US Government is moving towards a position that birth control pills are a form of abortion and

will eventually be banned.

[Mtnjim]

...I got an

email today from a female acquaintance who is telling me that the US Government is moving towards a position that

birth control pills are a form of abortion and will eventually be banned.

And capitol punishment is

retroactive abortion, think they'll ban that too?

[Rbt]

And capitol

punishment is retroactive abortion, think they'll ban that too?

Actually they pretty much have. The

death penalty is pretty much gone nationwide.

We are seeing quite a stir on the local news about some

pharmacists refusing to fill prescriptions for the morning after pills based on religious beliefs, with some talk

that some pharmacists are also sometimes refusing to fill BC prescriptions as well.

It is evident to me the

Republicans and some religious groups are working toward the elimination of the First Ammendment (that covers

freedom of choice and freedom of/from religion).

And I can't go along with those who say "the people" won't

let it happen. Just look at the dismal voter turnouts in this country. There are quite a few sheep, quite a few...




(Don't be suprised if along with bans on "suppliments" like vitamins etc we see a move to ban pheromone

products as well.)

[belgareth]

That's interesting about the

thought that birth control pills will be banned. I read in another place that there is some pressure to make them

available over the counter. That only makes sense as birth control pills have such a strong safety record. They are

statistically far less dangerous than tylonol.

I can't really see them ever being banned and am speculating

that it was either some religious group spouting nonsense or somebody trying to stir up panicked indignation. All

that will really happen if they are banned is a huge black market will spring up.

[koolking1]

but I'll find

that email and paste it here.

Personally, I think they should ban everything, we'd have a very robust

economy.

[idesign]

By the

same token, this creates opportunities for those totally inappropriate "bad boys".

If you date a woman who is

pregnant or on the pill, you just have to realize you are probably getting into something time limited.

You also

have to know that if you "let" your girlfriend or wife get on the pill, you are exposing your relationship to

possible stress, especially in the sexuality department. And it helps explain why pregnancy is often a difficult

time for couples.

This all certainly fits my personal experience, in both cases.

Every woman and man should be

taught this.

Nice post, Bel. We've known this for a number of years, but it's nice to see another study

supporting the conclusion.

This explains a lot of what we've been "up against" for a long time as male

partners in relationships with women, and I agree that men and women both should be aware of the pitfalls.

Doc,

could a parallel be drawn with men using steroids?

It seems that messing with something as fundamental to

behavior as hormones we're asking for trouble, or at least a more difficult situation.

Could you think of

hormonal manipulation as a lie? A chemical "lie" to your body which affects a physical cause, but also subtly (or

obviously) affecting your behavior, albeit tangentially? Perhaps if women are physically and emotionally "tricked"

into a non-mating behavior, they fall into the habit of not desiring men, emotionally or physically.

I think

there's a body of experiential evidence that could make a case for a trend toward "division" of the sexes in recent

history. I don't think I need to expand on that. Of course a lot of it has to do with "enlightenment" (I Am

Woman), but I wonder if there is some cause and effect going on. I'm clueless as always, but its interesting.

[koolking1]

"It seems unbelievable,

but the Bush Administration is quietly trying to redefine "abortion" to include birth control. The Houston Chronicle

says this could wipe out dozens of state laws that protect women's reproductive freedom and protect rape victims.

This "rule change" doesn't need congressional approval. "

Well, it's not a religious organization but a

political one,

MoveOn.Org

http://pol.moveon.org/contraception/...comment_pasteT