The Pill Makes Women Pick Bad Mates
Phantom Pain
Posts: 9,876
http://news.yahoo.com/s/livescience/20080813/sc_livescience/thepillmakeswomenpickbadmates
Jeanna Bryner
Senior Writer
LiveScience.com
Tue 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.
Jeanna Bryner
Senior Writer
LiveScience.com
Tue 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.
My drinking team has a hockey problem
The ONLY thing better than a glass of beer is tea with Miss McGill
A protuberance of flesh above the waistband of a tight pair of trousers
The ONLY thing better than a glass of beer is tea with Miss McGill
A protuberance of flesh above the waistband of a tight pair of trousers
Post edited by Unknown User on
0
Comments
Mystery solved !!
The ONLY thing better than a glass of beer is tea with Miss McGill
A protuberance of flesh above the waistband of a tight pair of trousers
look at this... and I was about to kill myself. Now, all I need to do is stop taking the pill and all my MAN worries will go away. Whohooooooooo!
the fake pregnancy thing is why it decreases your sex drive too. but then I think ok, so you go off the pill so you'll want more sex...but then you can't have it because you're not on the pill...sort of a catch 22 don't you think?
You're Welcome for the intervention
The ONLY thing better than a glass of beer is tea with Miss McGill
A protuberance of flesh above the waistband of a tight pair of trousers
It is weird
My buddy's wife turned into a pornstar after stopping the pill
Luckily they are trying for a baby
The ONLY thing better than a glass of beer is tea with Miss McGill
A protuberance of flesh above the waistband of a tight pair of trousers
"Sometimes life should be consumed in measured doses"
6-01-06
6/25/08
Free Speedy
and Metsy!
And then you will get pregnant Weeeeeeeeha!
Bridge School '06 Night 1 & 2
Venice '07 pummeled by the sleet!
Nijmegen '07
Werchter '07
April Fools ~ LA1
of course I am 2 girls shy of a threesome too..........
It's true.
and reveling in it's loyalty. It's made by forming coalitions
over specific principles, goals, and policies.
http://i36.tinypic.com/66j31x.jpg
(\__/)
( o.O)
(")_(")
i'm just happy if they don't spit it out
I think people wanting an unrealistic mate is the reason behind the divorce rates....and lack of effort.
You can only chalk up so many womanly things as "quirky".. At some point you gotta say to yourself...can hormones *really* do all that to a human brain? Apparently so if they are introduced synthetically on a daily basis...
and reveling in it's loyalty. It's made by forming coalitions
over specific principles, goals, and policies.
http://i36.tinypic.com/66j31x.jpg
(\__/)
( o.O)
(")_(")
hahahaha
"What a stupid lamb."
"What a sick, masochistic lion."
"Sometimes life should be consumed in measured doses"
6-01-06
6/25/08
Free Speedy
and Metsy!
"What a stupid lamb."
"What a sick, masochistic lion."
kevinbeetle: "Yes. When her career washes up and her and Gavin move to Galveston, you will meet her at Hot Topic shopping for a Japanese cheerleader outfit.
Next!"