Is There An Evolutionary Benefit for a Woman NOT Falling Asleep After Sex?
One of my students asked an interesting question today and I thought I would share my answer with you.
She asked me what the evolutionary benefit of a male refractory period might be. Considering how much pain has been caused by dudes squirting and rolling off, it’s quite a, uh, err, uh, loaded question.
One theory is that the penis is a beast of a seminal fluid plunger – you know – the super plunger you keep by the toilet for emergencies? Plunging other men’s sperm out of the vagina, gives his own sperm a chance to survive and fertilize the egg.
This plunger effect has been well demonstrated in lab studies.
Because the penis acts like a plunger, once a male has plunged other men’s sperm and ejaculated his own sperm, the theory states that the refractory period would allow him to NOT plunge his own sperm out of the vagina.
And so the story goes: ejaculate, get soft, sleep. Egg fertilized, end of story. Maybe.
Chemistry supports this theory as well. Research shows that men release a chemical bath into their system after orgasm that includes a dump of prolactin. Prolactin is linked to sexual satisfaction and also forces recovery time. It’s also linked to sleep. Prolactin levels are naturally elevated during sleep and research shows that animals injected with prolactin become sleepy almost immediately after injection.
So, no surprise, dudes tend to fall asleep after ejaculating.
Now here’s where things get really interesting. If you ask the wrong question, you can’t possibly arrive at the right answer.
I believe the whole question my student asked is incorrect. Her question points to our shared cultural delusion about women and sex. Culturally, we are told, women fundamentally don’t need sex, want sex, nor care about sex much.
And if they do, they’re told they shouldn’t.
Research tends to focus on male sexual behavior – why does HE fall asleep?
As if it really matters. You see what I’m getting at? What if it doesn’t matter that he falls asleep?
Perhaps we need to ask a different question. An upgraded question. Like the coffee – but better. One that’s more revealing about the reality of female sexuality, not the mythology.
Suppose we flip the question and ask, what is the evolutionary benefit for a woman NOT falling asleep after sex?
And more importantly, why can she just keep going and going and going and going?
In order to understand this question, we need to know that one of the reasons there are so many sperm in semen is because of sperm competition. Research shows that there are sperm whose primary purpose is to prevent other men’s sperm from fertilizing an egg. These are often called kamikaze sperm – and their purpose is to kill other men’s sperm in the vagina.
Here’s what else we know. We know that surviving sperm can live in vagina and the fallopian tubes for 3-5 days.
So, maybe the reason she can keep on going is so she can collect more sperm, from different males, in her vagina as soon after the initial sexual experience as possible.
The male has done his part – and he sleeps.
This makes sense with “premature” ejaculation too. Maybe it isn’t premature at all. Maybe it’s just perfect in that it allow a women to have sex with more men immediately after initial sex. Ejaculate in 30 seconds to three minutes. Sleep.
Now this gets cool. The female, not yet warmed up, much less sexually and orgasmically satisfied, can ask the great spiritual and existential question, “who’s next?”
Additionally, female vocalization during sex let’s people in the surrounding area know that sex is happening, leaving nearby males alert, awake and sexually primed.
Then most of the work is done. All she has to do is sex, vocalize, rinse and repeat.
In this way, the female can let the healthiest sperm win the battle to fertilize her egg, and receive all the benefits of social bonding – which are undeniably in her best interest for one day producing the healthiest offspring possible.
I know many will say this kind of female sexual behavior is immoral and should be controlled.
Yet I believe this behavior may be the true evolutionary benefit to the refractory period of men.