Game Show Host: Welcome to Is This a Real Sex Thing? Here's your first and only question: 

Which of these is not a real sex thing?

Being aroused by feet...

Using foods during sex, like melted chocolate or whipped cream...

...and enjoying being blindfolded during sex. 

It's a trick question. They're all real sex things.

[Host reveals herself to be Shan]

Shan Boodram: Hi, I'm Shan Boodram. This is Crash Course: Sex Ed.

Today we're talking about kinks and how common they really are. We'll be right back after these messages. 

[Theme music]

A kink is a non-conventional sexual behaviour or desire.

Things like wanting to be watched during sex or being really into rubber outfits.

Sometimes these desires live in the realm of of fantasy where just a mental image turns a person on and they don't actually act on it. 

Other times those desires are an active part of someone's sex life. 

As a culture, we often think of kinks as the Diablo level in the Taco Bell hotel sauce taxonomy. Mild is for the masses, but only some good for the really hot spicy stuff. 

Except apparently, a lot of people go for the spicy hot stuff. And kinks, they're more common than you might think. 

As we learned way back in our first episode, our ideas about which sexual expressions are normal are shaped by the time and place we live in. 

In reality, when it comes to sexuality and sexual behaviour, variety is the norm. 

Just check out these three studies from Canada, Italy, and the US. 

Over half of surveyed Canadians said they'd fantasise about having sex in public or being dominated. 

68% of Italians said they'd had a kinky fantasy at least once in their lives. The most common being voyeurism, or getting aroused by watching someone else get undressed, be naked, or engage in sexual activity. 

And more than 90% of surveyed Americans said they'd fantasised about being dominated or dominating their partner. 

No, the survey was not conducted in a movie theatre showing 50 Shades of Gray.

"But why, Shan?" I heard you asking. "Why do some people like pain or tentacle stuff or wearing diapers?" Wherefore art thou kinky?

Well, compared to other sex related topics, there hasn't been a ton of research about kinks. But from what studies have been done so far, the answer may be a lot of reasons. 

One hypothesis is that kinks are learned. Kind of like how Pavlov's dog started drooling when they heard a bell because they associated the sound with dinnertime. 

Sometimes if an early experience of pleasure co-stars a not obviously sexy object, sexy feelings can be linked to it and voila, a kink is born. 

Certain kinks may also correlate with personality traits like if someone is introverted or extroverted and those traits can be influenced by genetics. 

But the data on this is especially limited. It's just not something many researchers have asked people about. 

You might also have heard these kinds of sexual interests described as fetishes, but a fetish isn't the same thing as a kink. 

A kink broadly describes sexual behaviours, even if they're not actually that unusual. 

But a fetish is a particular type of kink where somebody's aroused by a specific object like leather or underwear or a non-genital body part like hair or feet. 

In any case, one 2017 study found that if somebody had a fetish, that's not the only way they wanted to have sex. They just extra enjoyed it that way. 

Here's the thing, though. When Diablo sauce, or mango habañero, or Da Bomb isn't something you're personally into, it's easy to get caught up in your own ick and judge people who do like it. 

That's part of why some people with fetishes may hesitate to tell their partners about them. But as long as everybody involved consents, kinks and fetishes can be a fun and fulfilling part of sex. 

Like to give one big example, a kink that often gets misunderstood is BDSM. 

The definition has changed over time, but today it's generally understood to cover bondage, discipline, and submission, sadism and masochism. Sex acts that often play with power dynamics or giving and receiving pain. 

Which might sound surprising. How does Ow translate into Ooh? 

Well, there's some evidence that the processing of pleasure and pain are closely linked in the brain, since they both are tangled up in the opioid and dopamine systems. 

But playing with pain requires caution.  Research has shown that injuries from BDSM activities do happen both intentionally and unintentionally, but the BDSM community puts a strong emphasis on consent and safety. 

In good BDSM practices, it's crucial to talk about what's on the table, and what's off limits before getting started, to use a safe word that puts a stop to the action at any time, and to move back into a place of care and gentleness as things taper off. 

And for many, it's the meaning given to the pain that makes it pleasurable.

Some people who enjoy BDSM say the contrast of pain makes the feeling of pleasure stronger. Kind of like adding salt to chocolate chip cookies to bring out the sweetness.

And sometimes BDSM isn't all about having sex. For a lot of people, the appeal is giving up power ot taking power in ways they don't always get to do in their everyday lives, what's called power exchange. 

The same could be said for furries. People who roleplay as human-like animals through art, writing, or dressing up in costumes known as fursuits as a part of their fursona. 

For some furries, that's partially a sex thing, but not always. The appeal can also be imagination, play, and the freedom of shedding their regular selves for a while.

Whether sex is part of the picture or not, no matter the reason, humans do be kinky. But is there a point where kinky behaviours go from "fun spicy taco topping" to "why would anyone make a sauce that hot"?

In other words, is there a point where kinks become a problem?

Well, it depends. Any good thing can become a problem if taken to extremes. But where exactly that line falls can be complicated. 

So-called "abnormal sexual interests" aren't inherently bad.

The DSM-5, the American Psychiatric Association's guide for classifying and diagnosing mental illnesses, uses the term paraphilia, para meaning going beyond, and filia meaning attachment, to describe an intense and persistent sexual interest between consenting, adult partners. 

By itself, this isn't necessarily a problem. But if someone's paraphilia becomes distressing or harmful to themselves or others, the DSM-5 classifies it as a paraphilic disorder. In this case, someone might be referred to a counsellor or prescribed a medication. 

Some experts warn that classifying certain behaviours as disorders is problematic because what's considered normal often depends on cultural and socio-political factors.

So, there are calls for more research around paraphilic disorders to clarify the DSM's classifications. Kinks aren't for everybody. If they were, they wouldn't be kinks.

But a lot of the ones that many people think of as unusual aren't as uncommon as they're made out to be. What we do, think, and feel when it comes to sex can be an expression of who we are, but it's also shaped by the time and place we live in. 

In the end, sexuality is deliciously diverse. That's a theme we've kept coming back to throughout this entire series. What's one persons "yes please" might be another person's "no thanks". 

And you know what? That's thrilling. There's room for everyone to have an amazing time with a partner who feels the same way. There's space to try new things, or return to tried and true favourites.

No matter the recipe, good sex comes down to the same ingredients: it's consensual and it's safe. And there's trust, fun, and delight for everybody involved. 

And with that, Crash Course: Sex Ed is a wrap. 

How are you feeling, Teen Shan?

Teen Shan: You've definitely cleared a lot of things up. Thanks, Old Shan. 

Shan: Girl, what are you calling old? 

Teen Shan: Whoops. One more condom balloon for the road. 

Shan: This episode of Crash Course: Sex Ed was produced in partnership with the Kinsey Institute at Indiana University. If you are interested in learning more, visit their website for resources that explore the topics we discussed in the video today. 

Thank you for watching this episode, which was filmed at our studio in Indianapolis and was made with the help of all these extremely talented people. If you want to keep Crash Course free for everyone forever, you can join our community on Patreon.