Falling asleep after sex

A few years ago, you pondered on why, or even if, guys fall asleep after sex. They do get drowsy, and for good reason, as I learned in a Psychology class.

The goal of a species is to reproduce, and while that may sound frivolous, nature does its best to help us with that. Primarily, nature makes sex feel good, so we want to do it. A lot. It is well-known, though, that a female is not guaranteed to become pregnant from a single act of copulation, so the more times she can copulate, the increased chances of getting pregnant and reproducing. After copulation, a male has typically given the female all the reproductive "help" he can offer. For that male to continue attempting copulation with the female would not increase the chances of her conceiving. To increase her chances, we need a new male, who can offer additional "help". But how does nature get the first male to leave? By releasing hormones that make him drowsy, so he'd rather go take a nap then try again with the female. On the flip side, females are capable of, and usually desire, multiple acts of copulation. Again, this is to increase the chances of conception.

Unfortunately, this does little to satisfy the frustration many women experience as part of humans monogamist society.

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Link to column: Wny do men feel sleepy after sex? -- CKDH

Wasthis a Desmond Morris Psyc class?

Where are all these women with an instinctive desire for multiple partners? And why don't any of them live near me?

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Bruce

Love Poems - http://www.geocities.com/SoHo/Lofts/9104/

[[The goal of a species is to reproduce, and while that may sound frivolous, nature does its best to help us with that. Primarily, nature makes sex feel good, so we want to do it. A lot. It is well-known, though, that a female is not guaranteed to become pregnant from a single act of copulation, so the more times she can copulate, the increased chances of getting pregnant and reproducing. After copulation, a male has typically given the female all the reproductive "help" he can offer. For that male to continue attempting copulation with the female would not increase the chances of her conceiving. ]]Plassmeyer


You sure about that? I don't doubt that the second (and third, etc.) time the sperm count is a bit lower, but I would still think another sperm armada would increase the chances of conception.

I may be wrong, but I heard a report that says that sperm already in the woman from one guy will actually attack and kill sperm coming in from another guy. Anyone else heard of this?

Wouldn't the hardiest sperm survive? That would support the multiple-partner theory in that the female would be fertilized by the best of the bunch.


"A winner every time!" --old carney saying

Sperm killing sperm sounds like a "modernized" version of the old idea that the spending from two guys would cancel each other out. That idea shows up from time to time in nineteenth century erotica. (Sounds like a lame attempt to talk a girl into a threesome: "If you let both of us, you can't get pregnant.")

In fact, sperm are fairly passive critters that don't do much of anything but mill around aimlessly until a pheromone or related "scent" is released by an egg to beckon them. I'm unaware of any offensive weaponry on the normal sperm.

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Tom~

Of course, the simple answer also works. After a session of spirited congress I tend to fall asleep 'cuz I'm TIRED. 'course when I was 18 I didn't tire out so easily (I did apologize alot, though).

Plass, I don't see how the male falling asleep makes room for the female to get a new sex partner. I can recall instances from my own life when I fell asleep ON my partner. If another guy wanted in, he would have had to waked (woken?) me up.

If you fell asleep ON your partner, you must be a little guy. No threat to the bigger club-wielder who wants to be next.

Re: So-called "killer sperm"



I read an article in Details Magazine within the last year talking about how human sperm all, similar to an ant colony, all have special duties. One of these is to stick around and fight sperm from other people, another way of having the fittest survive.



I tried an internet search on this to get some more evidence since I threw out the magazine, but put "sperm" and "killer" in any search engine and you get a lot of whale websites!



Other interesting sperm facts researchers have uncovered recently (according to the article) show that sperm will take naps while in there, eat other sperm for energy to continue onward, and that a ton of the little guys get spilled out immediately afterwards due to contractions the woman has!



Re: The emotional reaction a woman is likely to have when a man falls asleep soon after coitus (even though it was not brought up yet)



While as a guy I am as empathetic to a woman's feelings, I still can't help but appreciate Pamela Des Barres' attitude in her wonderful book I'm With the Band : Confessions of a Groupie, where she says that she likes it when her partner falls quickly asleep after the deed is done because it means he is totally content and she did a good job!


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Brian O'Neill
CMC International Records
www.cmcinternational.com

ICQ 35294890
AIM Scrabble1
Yahoo Messenger Brian_ONeil

Imagine the following hypothetical situation involving hypothetical cave-people:

1) Fred and Wilma 'well-you-know'.
2) Fred falls asleep and Wilma is unsatisfied.
3) Wilma goes off to find Barney.

Now, according to the the theory put forth in this thread, Fred falling asleep was a biological function meant to allow Barney to produce Pebbles. Does anyone else see a problem with this? (Besides Barney having a low sperm count that eventually leads to the adoption of Bam-Bam.) If a biological function is to be successful in the Darwinnian world, it has to to promote reproduction in the organisim that carries it, not deter the organisms reproduction.

I didn't want to get involved in this one, but I think the answer may lie in our closest relitives - other primates- do the male primates fall asleep after and when they do , do the females look for more- i find this unlikely since there is usally a competition between males for this but i don't know.
Also someone may have inadvertantly hit the nail on the head when they said that they weren't that tired when they were younger- back in the fred and wilma days man kind didn't live that long so the men wouldn't be falling asleep after and be alert enough to ward off any competition.

Taken a step further, it might be a primary function to introduce young blood into the mix of things. Y'know, so we don't keep making square wheels just because "that's the way we've always done it."

Regarding the specific tasks of sperm....
There is an entire book on this subject entitled "Sperm Wars". I can't remember who the author is but it came out about 3 years ago I think. It's ALL about different sperm having different functions. Some are just to get in the way of possible invading sperm, some just to get to the egg, etc. It's actually kind of an interesting book. It goes into all sorts of details dealing with sex such as why a woman is more likely to become pregnant from an affair than with her partner and how masturbating before sex will create a "fresh batch" of sperm that may fare better in "the big race". It's all very speculative, but interesting none-the-less.
ciao-lou

Lou--I think I read that book. Aren't there some sperm that are in touch with a mysterious "force", and can use it to confuse other sperm? And something about a dark side.....

Satan said: "... a ton of the little guys {sperm) get spilled out immediately afterwards due to contractions the woman has!"

I recall hearing (though I can't confirm) that the contractions produced by a woman's orgasm have the effect of creating a slight vacuum when finished, actually drawing semen further into her body. Finally, a biological justification for the joys of simultaneous orgasm!! Timing is everything.

Am I the only *woman* who falls asleep after sex? OK, preferably lots and lots of sex, but still... I like my cuddling beforehand, but afterwards, it's "that was swell...zzzzzzzzzz", lol.

You're not single and looking, are you?

Though I occasionally fall asleep "afterwards", I don't think it's any kind of hardwired response. For me, it's mostly a combination of: 1) being too relaxed and/or exhausted to want to get up immediately; 2) being in bed already; and often 3) being tired anyway because it's early morning or late evening.

In my experience, I prefer to have sex when I am full of energy and vitality, while any male partner I have ever had will have sex no matter how tired they are...

I'm male and I sure don't get sleepy after sex... just the opposite! Sure, I'm physically fatigued (we seldom bother with sex if we can't devote a lot of energy to it), but in just about every other way I'm so alert and feeling so great that even trying to sleep is usually pointless.

Why do you think I'm up and posting to this message board so late?

Is it a bad thing if I fall asleep DURING sex?

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It only hurts when I laugh.

I always thought it was because we didn't have the wet spot.

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President of the Vernon Dent fan club.

But how does nature get the first male to leave?

I can hear it now, *Honey, I'm not committing to our relationship out of respect for your biological imperative*

How about the theory that as the prehistoric man fall asleep he allows the woman (hopefully pregnant) to run off while he gets eaten by the big carnivore that was just around the corner?

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What's the ugliest part of your body?
Some say your nose, some say your toes,
But I think it's your Mind - Frank Zappa

[Patr100]

The theory I heard was that if conditions for the Caveman were "safe" enough for him to indulge in sex, (ie no predators around, enough food ), then he should also be biologically encouraged to rest as well as soon as possible, before conditions changed, hence the end of coitus encouraging sleep or rest.

[Blake]

That is the most ridiculous theory of all the ridiculous theories surrounding sex. And as with all of them the evidence is non-existent.

Firstly evolution occurs in groups, but selection works on individuals. It doesn’t matter what maximises the chance of the woman getting pregnant, it won’t affect male genes unless it maximises the chance of the male being the father. This theory proposes that men fall asleep to allow other men to have sex with their partners. Other men! With different genes! Did the person who proposed this theory stop to think? Did they understand how evolution works? Men with no ‘sleep’ genes will be guarding their partners. They will be ensuring that when they are capable of mating again they will be able to do so with no competing sperm inside their partner. Better still they will be absolutely sure they won’t be working to support another man’s child. That is a huge selective advantage to no having ‘sleep’ genes’. Any man with ‘sleep’ genes is decreasing his reproductive success. The genes will die out.


But we’ll ignore that it is ridiculous on evolutionary grounds. It is also ridiculous on physiological grounds. One ejaculation is enough to ensure pregnancy. In fact there are about 800 times more sperm ejaculated than are needed. A woman who has sex with another man, or another 100 men within 12 hours of having sex the first time won’t increase her chance of getting pregnant one iota. A woman does not and can not “increase her chances” by having “a new male, who can offer additional "help"”. The only way that could happen is if the sleeping partner is infertile, but by definition infertile men can’t pass on their genes.

Sorry but this is a load of old cobblers from start to finish and totally unworkable from a scientific viewpoint. I really wish that sociologists wouldn’t try concocting reasons for biological phenomenon when they lack the most basic knowledge required to do so.

Can we just stick to the most obvious solution? Drowsiness after sex is caused by depletion of those neurotransmitters responsible for alertness and stimulation. It serves no evolutionary purpose, but because it has no significant penalty it has been retained. At least that conclusion makes sense and can be supported with experimental evidence.

[moriah]

Talk about resurrecting an old thread. All the original participants are ghosts!

[Patr100]

Well, having come across the question on the Straight Dope archive and instead of starting a new thread, I used the search and found this thread under Cecil's colums. That's what people are supposed to do. Keeps all relevant comments in one place. If it surprises you, it shouldn't really.

[Duck Duck Goose]

It's always surprising to see resurrections.

From the FAQ:

What if I want to continue / add to the discussion on a topic that was mentioned in an old thread?

Start a new thread with a link to the old thread. A general guideline for "old" would be a thread older than three months.

[moriah]

Originally posted by Patr100
Well, having come across the question on the Straight Dope archive and instead of starting a new thread, I used the search and found this thread under Cecil's colums. That's what people are supposed to do. Keeps all relevant comments in one place. If it surprises you, it shouldn't really.

Supposed to do? You use your second post on this message board to lecture me on what is and isn't supposed to be done?

Either you've been lurking for a long time, or, you're some banned sock puppet if you think you know what's supposed to happen, especially, as DDG points out, it's contrary to the guidelines in the FAQ, which you didn't bother to read or are purposely flouting.

Impertinent newbie or troublesome oldie? I'll let the mods decide.

[Ponster]

Originally posted by moriah
Impertinent newbie or troublesome oldie? I'll let the mods decide.

[hijack]

Date Registered: 12-18-2003

Is that the answer you were looking for?

[/hijack]

[moriah]

Originally posted by Ponster
[hijack]

Date Registered: 12-18-2003

Is that the answer you were looking for?

[/hijack]

There's a 'profile' for the disgruntled banned who comes back with a brand new registered handle and stirs up trouble like opening up long dead threads. These offenders have been known to tip their hand by claiming knowledge of 'how things are here' even though they're supposedly only newly registered.

I'm not saying I know for sure in this case. But it might be worth an IP lookup.

Peace.

[Arnold Winkelried]

Yes, we do prefer that a new thread be started rather than "bump" a very old one. Also if you suspect a poster from being a troublemaker it is preferable to e-mail a moderator than to post suspicions on the board.

I trust we can all be friends now, exchange a hearty handshake, and focus on the issue at hand, namely the Straight Dope column "Why do men feel sleepy after sex?" (22-Dec-1995)

[rkts]

Firstly evolution occurs in groups, but selection works on individuals. It doesn’t matter what maximises the chance of the woman getting pregnant, it won’t affect male genes unless it maximises the chance of the male being the father.

I don't claim to have the best grasp of genetics and evolution, but it seems to me that if the mutation (is that the right word?) is fairly frequent, it can spread, without any selective advantage, throughout a group, and thus give the entire group a selective advantage.

Not that I don't think the theory is completely ridiculous.

[Blake]

I don't claim to have the best grasp of genetics and evolution, but it seems to me that if the mutation (is that the right word?) is fairly frequent, it can spread, without any selective advantage, throughout a group, and thus give the entire group a selective advantage.

That is theoretically possible if the trait conferred is neutral or near neutral to the individual. In this instance however the trait must be detrimental to the individual in order to work as postulated. The trait only confers an advantage to the female/group when it prevents the individual with the trait from reproducing. If it doesn’t prevent the carrier from reproducing then it has served no purpose at all. Its benefit to the group is directly correlated to its detriment to the carrier. Such traits cannot become widespread because those who carry the trait.

While traits like altruism can become fixed in a population despite being detrimental to the carrier they are never direct one-to-one correlations and never work only or mostly while being detrimental to the carrier. Altruism becomes fixed because altruists usually survive to save many individuals through the gene being expressed. In this instance sleepers can only ‘save’ another individual’s offspring when they sacrifice one of their own offspring. Even if the individual who’s offspring they ‘save’ is carrying the same gene, there will still only be one additional copy of the gene produced in return for sacrifice of the gene carried by their own offspring. It’s a zero sum game.

[rkts]

That is theoretically possible if the trait conferred is neutral or near neutral to the individual. In this instance however the trait must be detrimental to the individual in order to work as postulated.

The majority of times, I think, it wouldn't be detrimental to the individual, and therefore would be transferred to the offspring. Granted, this means, consequently, that its advantage to the group would be only slight, but so are a lot of things in evolution, it seems. How such slight advantages can become spread throughout a species is one of the things that confuses me about evolution.

You might say, of course, that that doesn't happen, and all advantages in evolution must be decisive, or else they wouldn't exist. Yet my understanding has always been that the complex structures which give organisms significant advantages must necessarily be evolved through a series of simple mutations that have only slight advantages. An example of this, I have heard, is the eye: it is far too complex to have spontaneously appeared in an individual, so it believed to have evolved in stages. First it was a very simple organ allowing perception of light and dark, providing information to the individual that was occasionally (but usually not) helpful; then it acquired muscles, and the ability to move, and thus became slightly more helpful; and so on. Yet these advantages were each so slight that they could not possibly have made much of a difference in the spreading of the gene.

Still, you might say, there's nothing to stop them from spreading, as long as they don't hurt anything. But by that reasoning, there's nothing to stop a mutation that kills 5% of its victims, since the other 95% would keep reproducing and spreading it around -- thus eventually decimating the species.

I entreat your elucidation. I'm sure I'm showing my ignorance here, but I am curious.

[Blake]

The majority of times, I think, it wouldn't be detrimental to the individual, and therefore would be transferred to the offspring.

You are missing the main point. It’s not whether it is not detrimental most of the time. It is the fact that it is detrimental every single time it works and that the detriment to the carrier always grossly outweighs the good to the group, no matter how well or how poorly it works.

By its very nature the gene can only be passed onto the offspring if it doesn’t work. If the man already has the woman pregnant then him falling asleep can’t work to make her more pregnant. If he doesn’t have the woman pregnant then the gene can work by allowing her to fall pregnant to someone else, but if she falls pregnant to someone else then the gene can’t be passed on.

The only way that the gene wouldn’t be detrimental the majority of times it is expressed if it doesn’t work the majority of times it is expressed. Benefit to the group is proportional to detriment to any carriers. But not directly proportional. The carrier loses one copy of his genes every time the gene works. Moreover he works to support a child that doesn’t carry his genes. That is a huge detriment. But the group gains only by having a child earlier. It doesn’t gain an entire new set of genes. A fertile couple having sex will fall pregnant within 6 months anyway. Over the carrier’s entire lifespan the tiny increase in production might amount to 1/10 of a set of genes if the woman never falls pregnant to him, in return for losing 4 complete copies.

There is no way that is going to happen. Slight advantages can spread through a group, but not if the advantage is always grossly outweighed by a disadvantage to all carriers. In this case that has to be the case. It doesn’t matter how well the gene works because the better it works the greater the detriment to the carrier and the lower the detriment to the carrier the less benefit there is to the group.

How such slight advantages can become spread throughout a species is one of the things that confuses me about evolution.

Slight advantages over many generations are multiplicative. It really is that simple.

Yet these advantages were each so slight that they could not possibly have made much of a difference in the spreading of the gene.

The thing is that they don’t need to make a big difference. Any difference will do. Imagine a stable population of 1 000, 000 organisms. A mutation arises that gives an advantage of 1 chance in 1 000, 000, 000 of being successful. For the first 1000 generations the gene will only exist in one organism, just as it did when it first arose. In the 1001 generation it will be found in 2 organisms. That means we now have 2 chances in 1 000, 000, 000 or 1 chance in 500, 000, 000 of being successful. So after a further 500 generations it will then be found in 3 organisms. After a further 333 generations it will be found in 4, then after a further 250 it will be found in 5 and so on. Very slowly but very surely the carriers of the new gene will increase. And as you can see the progression is logarithmic. Over vast time periods the smallest of advantages will become fixed.

there's nothing to stop them from spreading, as long as they don't hurt anything. But by that reasoning, there's nothing to stop a mutation that kills 5% of its victims, since the other 95% would keep reproducing and spreading it around -- thus eventually decimating the species.

That fails because of a reverse of the same principle. Imagine such a appears in a clutch of eggs that represents 0.0000000001% of the population. But of them 5% will die. Next generation only 0.00000000001% of the population will be carriers. The next generation 0.000000000001. When the percentage survival is less than the inverse integer of the population then the gene has been eliminated completely.

The reason the example in the OP is ridiculous is because if the advantage is 8% the detriment to the carrier will be 80%. If the advantage is 0.08% the disadvantage will be 0.8%. The gene will always be killing more carriers than it is creating. It is self annihilating.

[rkts]

That makes sense. I suppose I never considered that, while the number of organisms with the mutation multiplies, the rest of the population multiplies as well, and that the success of the gene is reflected not in the number of organisms possessing it, but in the percentage of the species carrying it. I always assumed that if a gene existed long enough, it would spread, like a disease, throughout the species, or at least that it had to in order to dominate the species. Hence my statement,

But by that reasoning, there's nothing to stop a mutation that kills 5% of its victims, since the other 95% would keep reproducing and spreading it around -- thus eventually decimating the species.

But I see the error in this now.

Thank you for the education.