9 Surprising Facts About the Scientific Study of Sex

vadimguzhva/iStock via Getty Images
vadimguzhva/iStock via Getty Images

The scientific study of sex is much more exciting than an awkward sex ed class. While writing my book Sex Weird-o-Pedia, these were some of the most interesting facts about science and sex that I came across.

1. Some sex researchers didn't want their findings to get into the wrong hands.

The pioneering sex researcher Richard von Krafft-Ebing didn’t want his knowledge in the hands of ordinary folk. So he wrote Psychopathia Sexualis, the founding document of modern sexology—which was published in Germany in 1886 then translated and published in English in 1939—in Latin to discourage regular Joes (and/or Janes) from reading it.

2. You burn more calories mowing the lawn than you do having sex.

Young woman poses for selfie while mowing the lawn
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Sex might seem strenuous when things get hot and heavy, but it's usually not that great of a workout. You'd have to go at it for nearly 200 minutes to burn as much energy having sex as you do during a 30-minute run. Even mowing the lawn burns about three times more calories than sex. According to the British Heart Foundation, sex burns about the same amount of energy per minute as ironing clothes.

3. A surprising number of mothers claim to be virgins.

In a 2013 study of several thousand pregnant women in the U.S. published by BMJ, about 1 percent of the participants claimed they were virgins when they gave birth. This, of course, calls into question the veracity of studies that rely on self-reported sexual behaviors.

4. Penicillin may have ignited the sexual revolution.

One economist says that penicillin, and not the birth control pill, was the real enabler of the sexual revolution. A study published in the Archives of Sexual Behavior in 2013 shows that penicillin contributed to a 75 percent decline in the number of deaths caused by syphilis from 1947 to 1957. Since the new treatment made sex safer, people started having riskier sex, which resulted in increases in the numbers of children born out of wedlock and teenage pregnancies.

5. Twins can have different dads.

A photo of fraternal twins
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While it is very rare, it is possible for fraternal twins to have two different fathers. What’s more common is for a rom-com to be based on this scenario.

6. Gender may influence how people handle sexual jealousy.

Research from evolutionary psychologists indicates that people’s gender influences how they react to sexual jealousy. For men, they react more strongly to sexual unfaithfulness than emotional infidelity. For women, it is the reverse. The theory behind these behaviors comes back to evolution: Males who were intolerant toward their wives becoming sexually active with other men were less likely to become an object of derision and more likely to see their own genes pass onto future generations. Women who prevented their husbands from emotionally bonding with other women reduced the chances of the men spending their resources on other women.

7. One of Ivan Pavlov's colleagues created his own (slightly x-rated) conditioning experiment with dogs.

You’re probably aware of Russian researcher Ivan Pavlov and his famous conditioning experiment in which he trained a dog to salivate at the sound of a bell. What you might not know is that one of Pavlov’s American students, W. Horsley Gantt, conditioned dogs to become sexually aroused when they heard specific tones. The experiment, according to Mandy Merck's In Your Face: 9 Sexual Studies, was intended "to study conflicts of the drives between ... experimentally induced anxiety states and sexual excitement."

8. Couples whose first child is a girl are more likely to get divorced.

Parents pay attention to their phones instead of their daughter
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Married couples whose first child is a girl are more likely to get divorced than those whose first child is a boy. Scientists are split as to why this is. One theory is that female embryos are better able to endure maternal stress than male embryos, so pregnant women in unhappy marriages are less likely to have a miscarriage if the child they are bearing is a girl. But once they have a daughter, these couples are more likely to split up since there were already fissures in their relationship prior to the child’s birth.

9. There's a link between pubic hair and STIs.

A downside of pubic grooming is that it might raise STI risk. In a study conducted by a University of Texas scholar, people who regularly shaved their pubic areas contracted STIs about 80 percent more often than those who never shaved down there. One suggestion is that those who regularly shave are more likely to tear their skin, making it easier for viruses to enter the body.

Ross Benes is the author of Sex Weird-o-Pedia: The Ultimate Book of Shocking, Scandalous, and Incredibly Bizarre Sex Facts.

This Smart Accessory Converts Your Instant Pot Into an Air Fryer

Amazon
Amazon

If you can make a recipe in a slow cooker, Dutch oven, or rice cooker, you can likely adapt it for an Instant Pot. Now, this all-in-one cooker can be converted into an air fryer with one handy accessory.

This Instant Pot air fryer lid—currently available on Amazon for $80—adds six new cooking functions to your 6-quart Instant Pot. You can select the air fry setting to get food hot and crispy fast, using as little as 2 tablespoons of oil. Other options include roast, bake, broil, dehydrate, and reheat.

Many dishes you would prepare in the oven or on the stovetop can be made in your Instant Pot when you switch out the lids. Chicken wings, French fries, and onion rings are just a few of the possibilities mentioned in the product description. And if you're used to frying being a hot, arduous process, this lid works without consuming a ton of energy or heating up your kitchen.

The lid comes with a multi-level air fry basket, a broiling and dehydrating tray, and a protective pad and storage cover. Check it out on Amazon.

For more clever ways to use your Instant Pot, take a look at these recipes.

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What Do Pets See When They Watch Television?

This dog would like to turn off Netflix's autoplay feature.
This dog would like to turn off Netflix's autoplay feature.
Amatore/iStock via Getty Images

In 2012, a television commercial aired in the UK for Bakers dog food that was conceived and produced specifically to attract the attention of dogs. The spot used high-frequency sounds that are inaudible to human ears. In theory, the dog would be so captivated by the advertisement that owners would take note and perhaps purchase Bakers for their next meal.

This didn’t quite work. Many dogs failed to react at all, proving that when it comes to television ads, humans may be more impressionable than canines.

While pets may not be so easily manipulated, they still find the television screen interesting, sometimes reacting to other dogs, animals, sounds, or images. But what is a dog really seeing when they tune in?

When it comes to color, television is no different from reality for a dog. They have dichromatic vision, which means they see the world through the range of two primary colors, yellow and blue. (Humans have trichromatic vision, able to see the full color spectrum.) Cone cells in canine eyes are also believed to blur their sight to a degree. More importantly, dogs process the frame rate, or “flicker fusion frequency,” of screens differently than people. Humans can detect movement at between 16 and 20 frames per second. Dogs need 70 frames per second or more. If they’re looking at an older television, it might resemble a flip book or even a strobe light effect to them. (Modern sets have a faster frame rate, which is why dogs might be more interested in your high-definition television.)

That helps explain the visuals. What about the content? Typically, dogs will react to the same things that would draw their attention in a room—barking, squeaking toys, or commands. In a study published in Animal Cognition in 2013, nine dogs were observed to see if they could pick out the face of another dog—regardless of breed—on a computer screen instead of another animal or a person. The dogs were rewarded with treats with a successful choice. Though the sample size was small, it indicated dogs can recognize other dogs on a screen. (Which you likely already knew if you’ve ever observed your dog suddenly on alert when a canine appears on camera.)

If your dog used to get excited by another dog on television but has since lost interest, it’s possible they simply became desensitized to their appearance, realizing the image in front of them isn’t going to move out of the boundaries of the monitor.

Content unrelated to dogs might not be of much interest. In a 2017 study published in the International Journal of Human-Computer Studies, dogs presented with three different viewing screens didn’t exhibit any particular preference for one over the other. If they were shown three screens at one time, they seemed uninterested in watching anything at all.

The study also noted that dogs had a limited television attention span. Rather than mimic the binge-watching habits of humans, dogs prefer to glance at a screen for a few seconds at a time. But that behavior could also be breed-specific. Dogs bred for hunting might be interested in moving objects, while dogs that rely more on smell might be indifferent.

And what about cats? In a study published in Applied Animal Behaviour Science in 2008, 125 shelter cats were given a television to view for up to three hours a day. The cats were split into five groups and given a variety of programming to watch, from humans to footage of prey to a blank screen. On average, cats spent just 6.1 percent of the observation time watching the screen. When they did, it was mostly to focus on the prey.

Because cats may react to images of birds and rodents on television, owners should avoid letting them watch unattended. You can also secure the set to a wall to make sure they don’t knock it down.

For the most part, dogs and cats are far more interested in what’s going on in the real world compared to what's on TV. We could probably take a lesson from their limited screen time.