20 Misconceptions About Sex - mental_floss on YouTube (Ep.212)

Hi, I'm Aaron Carroll

You can usually find me here at Healthcare Triage, but today we're going to head over to the salon for mental floss, where I'll be talking to you about 20 myths and misconceptions

about sex. Look, fair warning here, this is an episode about sex

If you think that's inappropriate or it's not your thing, probably a good idea to turn this off now

Did you know that it's a myth that there's any correlation between penis size and shoe size

There have been many studies on this amazingly enough, and they fail to find any link between

the size of a man's shoes and the size of a man's stretch or erect penis

There's also no relationship between his penis and the size of his hands or ears, or anything

else for that matter. Looking at his shoes will only tell you about his taste in footwear

And that's the first of many misconceptions about sex I'm going to debunk today

It's a myth that the average man has a seven inch penis. Let's be honest, to study this correctly you can't ask men how big their penises are

you have to get in there and measure yourself. We found 15 studies that looked at stretched penile length, and most of them had an average

around 5 inches. Here in Indiana, the Kinsey Institute studied more than 1600 men and found an average erect

penis size was about 5.6 inches. Interestingly, erections brought about by oral sex were larger than erections brought

about by manual stimulation. Is that cause oral sex causes bigger erections, or is it cause bigger penises get oral sex

We have no idea. It's a myth that wearing a condom makes you last longer. In a study of 500 men from Europe and America

their intravaginal ejaculation latency time was 5.4 minutes. They literally clocked these men with a stopwatch

Men 18 to 30 years old lasted the longest at 6.5 minutes on average

dropping to only 4.3 minutes for men over 51. Wearing a condom made no difference

nor did whether the men were circumcised. Here, Clark Kent's super speed backfires

Aquaman wins. It's a myth that you can build up a much bigger load

I'm not sure why so many people care about this, But here we go

In 2005, a study of more than 6,000 men who had provided about 9,500 samples was published

Men who waited a week had an average ejaculate volume of 3.7 milliliters

Men who had sex the day before had a volume of 2.3 milliliters

That's a difference of less than a third of a teaspoon. But even men who came earlier that day

still produced 2.4 milliliters. So we can't imagine that waiting is worth it

It's a myth that men want blondes more than brunettes. Sure, there have been some local studies that point to the fact that men may say this

but they're usually in places where blonde hair is less common. In areas where blonde hair is more common, the preference is not as clear

There's also no correlation in studies between women having blonde hair and having more sexual partners, more sex, or more orgasms

It's a myth that most women are going hairless these days. Yes it true that Playboy centerfolds are more likely to have little or no pubic hair in recent years but that a skewed sample A 2010 survey of more than 2 women found that only 11 of women

aged 18 to 68 remove all of their hair most of the time. 20% remove no hair at all, and only about

a quarter remove their pubic hair some of the time. Going bare is somewhat related to age

with 21% of 18 to 24-year-olds shaving it all off, versus 9% of women in their 30s

or 2% of women over 50. Bottom line, though, is that the majority of women

of all ages keep some hair down there. It's a myth that bigger breasts are less sensitive

than smaller breasts. Some people have argued that bigger breasts have longer nerves to get to the skin

and that this makes them feel less. Of course, then taller women would have less sensitivity, too

and no one makes that argument. The evidence for this comes from studies that asked women

if they could feel hair-like filaments of different sizes on their breasts

There were differences, but no woman ever defined sensitivity during sex as the ability to feel a single hair. Besides, no one argues that men

with smaller penises derive more pleasure than men with large penises. It's a myth that sex is

great exercise. Yeah, it burns off some calories, but most people aren't active for that long

30 minutes of sex might burn off 85 to 150 calories, but remember the average intravaginal

ejaculation latency time I mentioned before? Not even close. The time that sex is aerobic

where your heart rate goes up is even shorter. Despite what you've learned from our highly scientific competitor mad men

it's a myth that all men cheat, or that there's a difference between men and women

If you define cheating as intercourse, then yeah, men cheat more often. If you broaden it to include other acts

then women cheat pretty much as often as men. Surprisingly, age doesn't seem to be a factor either

The most comprehensive study we've seen showed that 23% of men and 19% of women

had cheated in their current relationship. The biggest predictor was being unhappy or incompatible in terms of sexual attitudes or values

It's a myth that men peak sexually long before women. What does peak mean anyway

If you define it to be the frequency of sex, then both men and women are likely to go without it for a whole year during their 20s

If we define it by masturbation, they're both most likely to do it in their late 20s

If we define it by oral sex, men are most likely to get it in their late 20s and give it in their 30s

Women are most likely to give and receive it in their late 20s. If we define sex at least four times a week, it's 30s or 40s for men and late 20s for women

There's no metric that makes this myth true. Speaking of sexual peaks, did you ever wonder if Spider-Man was a metaphor for going through puberty

It's a myth that young men are more likely to ejaculate prematurely. If we define that as climaxing too early, then studies have shown that 30% of 18 to 29-year-olds have an issue

But so do 32 of men in their 30s 28 of men in their 40s and 32 of men in their 50s For most men it a transient issue that goes away For men with severe and lifelong premature ejaculation it actually worsens as men age

It's a myth that men think about sex every seven seconds. This one defies belief

It would be sex, sex, sex, all day. That would be more than 57,000 times a day

It's pretty much every time you take a breath. Over 40% of men report thinking about sex only a few times a month or a few times a week

4% of men, they think about sex less than once a month. There's no truth to this one at all

It's a myth that married people don't masturbate. Lots and lots of people masturbate

A study of college students found that 98% of males and 44% of females reported having masturbated

Males averaged 12 times a month and females averaged 5. A study of married people found that 85% of men and 45% of women had masturbated in the last year

It's a myth that dead males can develop erections. Who comes up with this stuff

Anyway, do an internet search and you're bound to come up with a news story about a woman in Missouri who worked in a mortuary and was arrested

after becoming pregnant from a cadaver she, well, worked on. It's a hoax

What's also a hoax is the idea that a cadaver could develop an erection. Can't happen

If you die flaccid, you're flaccid for good. It is possible to die with an erection though, and keep it

It actually occurred pretty often in men who died by hanging. You still can't cause a dead body to ejaculate though

It's a myth that only males have wet dreams. First of all, let's stipulate that a wet dream is a state of sexual arousal while asleep

that results in orgasm that wakes you up. More than one study has found that about 40% of females report having had this happen to them

About 30% of females report this happening in the last year. The numbers for men are higher, but women ain't doing too badly

It's a myth that masturbating will make you go blind. I mean, come on

If this were true, you two would be a total waste of time because almost none of you will be able to see the videos

This is just totally untrue. But here's a fun fact. John Harvey Kellogg was a famous nutritionist and sexual advisor

He developed a number of foods, including his eponymous Corn Flakes, to reduce sexual desire and stop masturbation

I don't think they work. It's a myth that the pill will make you gain weight. When the pill was first developed

it contained very, very high levels of both estrogen and progestin. But the pill as it exists today is much more refined

and contains far lower levels of hormones. A meta-ysis by the Cochrane Collaboration

found 49, yes, 49 studies that compared the pill to a placebo

on other pills with respect to weight gain. None of the studies that compared the pill to placebo

showed that birth control pills cause weight gain. I'm not saying you're guaranteed not to gain weight

if you go on the pill but it likely not because of the pill This pill full of candy will make you gain weight It still won make your kids hyper though It a myth that you can game having a boy or girl by how you have sex

You just can't. Some people say that X sperm are bigger than Y sperm because the X chromosome is significantly

bigger than the Y chromosome. Therefore, if ejaculation occurs further from the cervix, Y sperm have a better chance of

overtaking the X sperm and making it to the egg first. So if you want a girl, go for a deep ejaculation

If you want a boy, do the opposite. Another explanation has it that X-sperm are hardier than Y-sperm

So if you ejaculate farther from the cervix, X-sperm are more likely to make it all the

way to the egg first. If this is true, if you want a boy, go for a deep ejaculation

If you want a girl, do the opposite. Or just recognize that all of this is ridiculous

It's a myth that you don't need the HPV vaccine until you're having sex

First of all, you need to be fully vaccinated before you're ever exposed to HPV for the

vaccine to work. And that takes time. So once you've had sex, it may be too late

HPV is really common. So is sex. By the end of their teenage years

more than three quarters of all adolescents have engaged in sexual intercourse

More than two thirds of them have had sex with at least two people. More than 6% of children in the United States

have sexual intercourse before the age of 13, and younger kids are the least likely to use protection

The HPV vaccine is about prevention. Get it early. And we return to the salon to talk about the myth

that the HPV vaccine encourages girls to have sex. This has been studied through a cohort

of almost 1,400 girls, 493 who'd received the vaccine. Researchers followed them for three years after immunization

to see if there were any differences in sexual outcomes. There weren't any

The girls who got the vaccine didn't get any more sexually transmitted infections

they didn't get pregnant more often, and they didn't seek contraceptive counseling more

The HPV vaccine only protected them. Thanks for watching Mental Floss on YouTube

which is made with the help of all of these nice people. Again, I'm Dr. Aaron Carroll

And hey, if you like this episode, you might want to buy our recently published book

Don't put that in there and 69 other sex myths debunked. You can get it at bookstores everywhere

and links are in the text below. Buy a copy. I'd really appreciate it

You can also find me regularly on Healthcare Triage, film right over there. We talk about everything health and health policy-related

Links also down below. Every week, we endeavor to answer one of your mind-blowing questions

This week's question comes from BShay13, who asks, Why is there no metric version of time, like a base 10 time system or something

Well, Bichet, there is, but no one uses it. It uses base units that are somewhat equivalent to decimal divisions of the day

like 1 10th, 100th, 1 1,000th, etc. Lots of different names have been proposed for these divisions

like TIC, MEC, CHI, CRON, and MOMENT. In 1897, in France, a committee proposed switching to metric time

but the idea never gained popularity. Thanks again for watching. Don't forget to be awesome

Remember to wear a condom