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Why Does Pornography Exist?

The answer may reveal a lot about our primate origins.

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Why is there pornography?

Silly question, right? Porn exists because people like to watch it. If people didn’t like to watch it, no one would make any money producing it.

But here’s a more interesting question: Why do people like to watch others having sex? After all, if I’m hungry I don’t get any pleasure from watching someone else eat dinner. Why should sex be different?

As a sex therapist and student of human sexuality, I’m convinced the answer has to do with the fact that we’re a highly social species.

The loud cries that some women make when they’re highly aroused are a regular feature of porn sex. This phenomenon, which scientists refer to as “Female Copulatory Vocalization (FCV),” turns out to be common in highly social primate species (1). It’s at first glance an odd behavior. Announcing to whoever is within earshot that you’re having sex might not have been the greatest idea in a dense forest with predators lurking all around.

As Chris Ryan and Cacilda Jetha discuss in Sex at Dawn, it’s likely that the original purpose of FCV in highly social primates like ourselves was to attract others of your species. If you heard sexy noises from the tree next door, it probably made you want to climb on over and join the festivities. Human testicles are built to deliver an enormous quantity of sperm — something that would only be necessary for a kind of intra-vaginal “arms race” where a male’s sperm was competing against those of everyone else who’d mated with his female partner that day.

Long ago, when there weren’t any bedroom doors, sex must have been a somewhat public event. If you saw and heard a couple having sex, that must have acted as an incentive to come join them.

Committed couples today have sex for all sorts of non-reproductive reasons, including to soothe each other, make peace, and reinforce their mutual commitment. Promiscuous matings in early human times probably served all of these purposes with respect to the group, which no doubt faced the same challenges in figuring out how to share resources, manage hurt feelings, and get along with each other. It’s likely that promiscuous sex on the plains of Africa 100,000 or so years ago may have helped ease social tension and foster cooperation and communal well-being.

Whether the result was a full-on orgy or not probably depended on the particular culture of your hunter-gatherer community (2). Some probably encouraged this kind of thing, and some didn’t. But some degree of promiscuous mating must have been common.

Of course, we humans are also endowed with strong pair-bonding instincts, which make us jealous and motivate us to seek a sexually exclusive relationship with just one person. The tension between our monogamous tendencies and our promiscuous ones no doubt made for quite a drama during the last few million years of human evolution.

Over time, monogamy managed to gain the upper hand. The development of language 40,000 or so years ago must have been a game-changer in this regard (2), since it was now possible for the first time in human history to ask questions like, “Who was that hunter-gatherer I saw you with last night?”

The invention of agriculture 10,000 years ago was surely another milestone (1,2) since it would have given rise to the idea of ownership: “My land, my farm tools, my crops," and, eventually, “my spouse.” Religious and legal institutions then cemented monogamy even more firmly in place.

But we’ve never quite lost our promiscuous tendencies. And the proof of this is that we still love to watch other humans have sex, just as we did on the plains 100,000 years ago. It’s in our DNA.

Our interest in watching other people have sex may be a vestige of an earlier stage in human history. But in the 21st century, porn has become for many a staple of everyday life. In 2017 there were 28.5 billion visits to PorhHub alone, a number roughly equal to four times the Earth's total human population (3).

More people today seem to accept the fact that their partners regularly go online to watch other people having sex. The degree to which this is a problem or not may well depend on the frequency with which a couple has sex together. As I write in my book, Love Worth Making: How to Have Ridiculously Great Sex in a Long-Lasting Relationship (4), sex is a lot like Pavlov’s dog: If you end up having more sex with your computer than with your partner, then over time you’ll end up with more pleasurable associations to your computer. Often the best solution is to make sure you have more orgasms in bed with your partner than in front of a screen.

The fact that most of us like to watch other people having sex is clearly part of our evolutionary heritage. With a little wisdom, most can manage this so it doesn’t overwhelm their erotic bond to their partners. For many others, though, the natural urge to watch others have sex can create a whole host of problems. And in such cases, it can be quite valuable to understand how deeply this urge is rooted in the early history of our species.

© Stephen Snyder MD 2018.


1. Ryan C and Jetha C: Sex at Dawn: How We Mate, Why We Stray, and What It Means for Modern Relationships. New York: Harper Perennial Reprint Edition, 2011.

2. Harari YN: Sapiens - A Brief History of Humankind. New York: Harper Perennial Reprint Edition, 2018.

3. Pornhub Insights: 2017 Year in Review -

4. Snyder S: Love Worth Making: How to Have Ridiculously Great Sex in a Long-Lasting Relationship. New York: St Martin's Press, 2018.

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