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
Aleksandr Zhurilo/iStock via Getty Images

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.

New Cross-Bred Cosmic Crisp Apples Can Stay Fresh for Up to a Year

Cosmic Crisp
Cosmic Crisp

Healthy snackers know only too well the disappointment that comes with biting into what looks like a deliciously crisp apple and getting a mouthful of mealy mush instead. It’s just one of the pome fruit’s many potential issues—they also brown quickly, bruise easily, and don’t last as long as whatever bag of chips you might be tempted to reach for instead.

Enter the Cosmic Crisp, a Washington-grown patented hybrid apple that could be the answer to all your apple-related complaints. According to New Atlas, researchers at Washington State University began breeding the new variety as a cross between Enterprise and Honeycrisp apples in 1997, and it’s officially hitting stores now.

cosmic crisp apple on tree
Cosmic Crisp

Not only does a Cosmic Crisp apple resist bruising and browning better than other kinds of apples, it also boasts an exceptionally long storage life. In a controlled atmosphere, it should stay fresh for a full year—meaning you’ll soon be able to enjoy a crisp, satisfying snack in the middle of March, when out-of-season apples usually leave much to be desired. In your own refrigerator, Cosmic Crisp apples are good for about six months, and they’ll even last for several weeks if you leave them out at room temperature. The long shelf life might cut down on the number of apples that you end up tossing in the trash because they went bad before you got around to eating them.

In a 2012 report published in the American Society for Horticultural Science journal HortScience, the Washington State University researchers found that a group of 114 consumers rated the Cosmic Crisp apple, or WA 38, higher than Fuji apples in sweetness, sourness, flavor intensity, crispness, firmness, juiciness, and overall acceptance. The apple's website even suggests that bakers can reduce the amount of added sugar in recipes that contain Cosmic Crisps.

The Cosmic part of its name comes from the whitish specks on the apple’s skin, which reminded taste testers of a starry sky. In reality, those specks are lenticels—porous openings that allow the apple to exchange gases with its environment.

If you don’t see Cosmic Crisp apples in your grocery store yet, here’s a simple trick for keeping any apples fresh for longer.

[h/t New Atlas]

The Reason So Many Babies Are Conceived in Winter

yurizhuravov/iStock via Getty Images
yurizhuravov/iStock via Getty Images

Does it feel like many friends and family members announce the pending arrival of a baby during the fall and winter months? That’s not exactly a coincidence. It turns out the cold season is associated with more reproductive activity than any other time of the year. The month of December alone accounts for 9 percent of conceptions in the United States. Science is gaining a better understanding of why.

All living creatures heed an evolutionary instinct to target seasonal births. If conception happens during colder months, babies will be born during warmer months, when resources will be bountiful. Northern states have births peaking in June and July, while southern states come a bit later in October and November. The farther south, the later the birth peak, since people in these warm climates are less influenced by frigid temperatures.

What are frisky humans responding to in colder months? Research suggests that the cooler temperatures and shortened days signal that it's time to get busy. Other theories suggest that men may be more fertile in colder months, or that a woman’s ovum receptivity might change with decreased daylight. Not only are couples potentially more sexually active, but that activity might wind up being more (re)productive.

Are there benefits to conceiving at other times? Possibly. One 2013 study published in the Proceedings of the National Academy of Sciences gathered data from nearly 1.5 million births and found that average birth weight in the first five months of the year decreased by 10 grams. Babies born during the summer months were 20 grams heavier. Mothers who conceived in summer tended to gain more weight than those who conceived at other times.

If you have a disproportionate amount of friends with a September birthday, it’s likely that their parents consciously or unconsciously followed their evolutionary instinct nine months earlier.

[h/t Smithsonian]

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