Why Does Prostate-Stimulation in Men Produce Arousal? : A Biological Argument

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Photo by Romi Yusardi on Unsplash

The are logical flaws with prostate-sourced male arousal being used as a defense of “natural or divinely inspired homosexuality”. This is a critique of the logic of a single argument, per biology. This is not a criticism of the gay community, which I am very supportive of.

To say “This feels good thus it is natural and healthy” is like saying “Simply because opium feels good when abused, this indicates that abusing opium is a natural and healthy behavior.” The human mind is sensitive to opium, it makes the person feel good, but consuming opium is by no means a healthy behavior.

The point being that all things that are true about biological life are true for a reason; the reason is that these things are true because they assist the organism’s survival. Opium in this case increases the survival of the poppy, and just because the poison makes a person feel good doesn’t mean that being poisoned by opium is a natural or healthy behavior.

For the pleasure of opium to be a justification of an argument that opium use is beneficial to humans, the human mind must have originally been immune to the effects of opium, and then developed a mutation that allowed it to get high. This mutation must have allowed these sensitive people to survive at a far greater rate than those who were immune to opium for this trait to become ubiquitous within the human race. This didn’t happen.

Opium is the plant’s natural defense mechanism; it is a poison that compels insects and animals not to eat it or otherwise kills them if they do. This puts opium in the same category as spicy foods. These plants evolved spiciness as a means to protect themselves from predators because this worked, animals were less tempted to eat the spicy plants than the non-spicy plants, so spicy plants survived more, reproduced more, and the trait became ubiquitous within the foods. Even though some humans enjoy spicy foods, this doesn’t make the spiciness any less of a natural defense mechanism for the plant.

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The issue with the common argument in the title is that feeling sexual pleasure from the prostate when receiving anal sex does not create any sort of biological advantage that would cause those who engage in it to succeed where others would fail.

Men feeling pleasure from anal sex must have had greater capacity to survive and then reproduce with women, entirely due to the pleasure of anal sex, in order for prostate-arousal to become a ubiquitous trait in the species. Basically, this would mean the men receiving pleasure from anal sex became so much more capable of surviving, competing, and reproducing than the men who did not receive anal sex, that this forced those who did not receive this pleasure from prostate stimulation into extinction.

Clearly this didn’t happen. If this did happen, then men who receive anal sex today would also exhibit this trait of being far more capable of and prone to competing and reproducing than those who do not. This is not the case, as most of the people who engage in this are gay men, and gay men don’t tend to reproduce at the same rate as straight men. This is because if prostate-arousal wasn’t the key to the success of the person, then it wouldn’t have become ubiquitous. It wouldn’t be selected in favor of if it provided no advantage over those who lacked arousal from prostate-stimulation, and this means it would only be present at a random rate, a benign mutation, rather than a 100% rate within men.

The major flaw with this argument is that a male receiving anal sex is, naturally, without protection, the antithesis of advantageous. It gives men a much higher propensity to catch sexually transmitted diseases. These diseases can often be very debilitating, and beyond that, these diseases would be transferred to these men’s mates, then their children are now at risk of being affected by this dangerous disease.

These men would need to have engaged in anal sex BEFORE reproducing for this trait to be selected in favor of. For prostate-arousal to be accounted for by men receiving anal sex, this anal sex must have provided an advantage that allowed this man to reliably survive in situations where those who lacked it died before they could reproduce. If it provided him a benefit only after he reproduced, it would not be an influential factor in selection. Think of this like saving a document, copying that document, and then changing the original file after you have copied it. Any changes made to the original after being copied are not passed down to the copy.

Knowing that anal sex provides a significant increase in risk for venereal disease which both harms the capacity of the individual to survive, as well as their mate and their children; we can readily understand that prostate-arousal did not arise due to men consistently receiving anal sex in a way that reliably provides some sort of advantage in the wild. Diseases is a major disadvantage, and a man receiving anal sex from another man isn’t going to give them any increased capacity to compete in the wild through means such as hunting, gathering, or fending off predators.


That being said, we still must acknowledge the point that prostate-arousal is a very real phenomenon. This means that the arousal from prostate-stimulation did provide a significant advantage in the wild, causing humans and their ancestors to become more so capable of surviving and/or reproducing than those who lacked this prostate based arousal. As we can see that this is not related to men receiving anal sex, then we have few possibilities remaining.

The most readily visible explanation for prostate-arousal just requires one to look at where the prostate is and how it is stimulated. It is stimulated by putting things into the rectum of the person. This is part of the digestive tract, the place where poop is naturally stored.

Knowing that it is not a penis that is stimulating the prostate, yet the prostate still must be stimulated regularly in a way that increases the person’s ability to reproduce successfully, the only reasonable suspect here is poop. This would mean that poop is what naturally stimulates the prostate, and when poop stimulates the prostate, the person has a greater chance of reproducing successfully, meaning that the children go on to survive and themselves reproduce. This also means that those who lacked prostate stimulation were less capable of surviving; otherwise the phenomenon of arousal from prostate-stimulation would not have become present in all humans as those who did not experience this stimulation would not have died out or been forced into extinction.

Poop is the key here, because to have poop in your system you must be eating. You must be healthy, having solid, substantial stools that stay inside of your rectum rather than other types of feces produced, often by diseases like cholera or otherwise that would give you loose watery stool. Only this solid poop is capable of providing the stimulation. Solid poop is visibly very similar in look and shape to a penis or fingers, which explains why both are capable of stimulating the prostate in the same sense as poop, all while watery poop or a lack of poop due to hunger cannot.

The advantage provided here is that people who were eating well and were healthy would feel very compelled to reproduce due to their prostate being stimulated by the solid stools in their rectum. Those who were going hungry or otherwise sick would feel less compelled due to their sickness.

This explains why it becomes universal throughout the species. Those who were aroused on a static level would be just as prone to reproducing when they are sick or hungry, and this means the children born as a result would likely be exposed to these sicknesses and hunger, and this would mean their children are much less likely to survive.

The poop-dependent arousal induced by the prostate gives people an instinct that compels them to reproduce when times are good, meaning their children are likely to survive, rather than the instinct seen in other animals that take any opportunity they can find to reproduce.

This discretion is the key to success, because humans are a very large animal that produces few offspring. They have a long rate of maturity to reach fertility, and the risk of having children means a risk of dying in childbirth. This is a major problem when it takes many years for a woman to reach the point where she can reproduce.

It was likely very hard for a man to find another woman, as the human race originally had a very low population. If your mate died in childbirth due to malnutrition or sickness, finding another woman to reproduce with would be a daunting task. As your child would die without their mother to nurse them, this means that choosing the right time to reproduce essentially meant life or death for your bloodline.

Ensuring that people are well-fed and not sick before reproducing increases the probability that the woman survives to nurse the child, and that the child itself survives due to not being sick and having enough to eat. Male prostate-based arousal is the key to this, because naturally the man is usually the one who makes the decision to reproduce and initiates reproduction. If the men are prone to making that decision when times are good, then the baby is more likely to survive, and prostate arousal from solid, substantial stool is a reliable biological indicator of health and bounty in the wild.

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Now that we can understand a sensible reason that justifies male arousal from prostate-stimulation, we can now try to explain the other aspects of the situation that cause this confusion.

The comparison to heroin or spicy foods shows us that we react to things in ways that often aren’t what nature intended. The thing about prostate-stimulation is that nature did intend for this to stimulate men, but it intended for this to be done by poop. Using fingers or another man’s penis to do this is essentially pressing the button yourself, rather than letting poop do it.

This is similar to this situation. If you had a pool that would drain water when the bobbing sensor detected that it was over full due to rain, this is a very functional system. When it rains a lot, the pool will automatically drain the excess water. The thing is, if you have the capacity to interact with this water detection lever, just to pull it up artificially, this would make the sensor think that the pool was overflowing, and the mechanical nature of the switch would still cause the pool to drain even though it wasn’t really full. This is just human interference in a system, and this can often produce results that are contrary to the design and intent of the system in question.

People may ask, “If men aren’t designed to have anal sex with one another, why does the penis fit inside of the anus and rectum so readily?”

The thing is, a penis really doesn’t go in there readily, at least when the anus is compared to the vagina which is naturally designed to receive the penis. The vagina naturally lubricates itself in order to allow the penis to enter. The anus does not. If the anus were intended to receive penis, then the anus would automatically lubricate itself in the same sense that the vagina does.

“Why does the penis fit inside of the anus and rectum at all if these organs are not intended to receive the penis?”

This is a mix of coincidence and survival here. Poop is similar in shape and size to a penis, and as we can deduce that nothing in nature occurs due to pure randomness, this means that there is a reason that poop in humans is the same shape as a penis, and this holds true even in other animals known to engage in male-male anal sex such as wolves, whose poop is also a similar shape to their own penises.

The ability for the anus to receive the penis is a survival mechanism. This is an advantage because in a situation where a person is anally raped by a man, if their rectum is readily pierced by this and they just die from internal bleeding, this makes them unable to reproduce.

If the rectum could not tolerate a penis, then this means that anal rape becomes a lethal weapon, beyond the disease it may spread, because the rectum is ruptured or otherwise severely damaged by this rape in a way that kills the victim. The anus evolves to tolerate this anal sex because it is an advantage to survive this situation rather than die due to being anally raped.

The animal ancestors of humans, and especially humans, were able to survive being anally raped and then go on to reproduce, while those who died from being anally raped did not. When anal rape was a selective event, one that killed off people unable to survive the experience, this left only the people capable of surviving being anally raped to reproduce.

While every person likely was not anally raped in the wild, humans are a notoriously libidinous animal. They engage in a frequent amount of sex and tend to seek out sex at high rates. When this is true, then many men would be, and still are, tempted to put their penis into anything, including buttholes, when their instinct is telling them that they should be putting their penis inside something right now due to their libido.

The relatively extreme prevalence of high degrees of sexual intercourse within the human species would lead to a comparably high degree of rape occurring, including a high degree of male-on-male anal rape, and for whatever reason male-on-female anal rape as women are equally as capable of receiving anal sex as men.

Alpha Wolves are known to anally rape other wolves to assert their dominance, and this could be one of many possible reasons as to why people were so frequently exposed to anal sex that they evolved as a whole to be designed to survive this experience. This is not the only reason, but we know that anal rape was common enough that anyone who could not survive this experience was reliably killed off over the course of millions of years.

In short:

Why does prostate-stimulation produce arousal?

It’s designed to be stimulated by solid stool in the rectum as a sign of good health and a stable food source.

Why do other means such as penises or fingers stimulate the prostate?

Because these things are largely identical in shape to poop. It’s using an artificial/unnatural tool upon a system rather than the natural one it was designed to use. It’s using a different tool that hits the button in the same way, causing the same reaction that would happen if the button were pressed naturally by poop.

Why does the penis fit inside of the rectum?

This is a defense mechanism against anal rape. If people just died upon being anally raped, many would not go on to reproduce.

Due to the high degree of libido in people, and any alleged predisposition to violent acts, this makes rape, including anal rape, a very real there at risk that humans, especially the feral lawless humans, were often faced with.

Basically, anal rape was so common over the millions of years of human evolution that those who could not survive this act were killed before reproducing. This left only those who were capable of surviving the act went on to reproduce.

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