eBook now available

You can now read the best of the Physics of Sex in the eBook from Amazon.



It's chock full of tips and tidbits from the blog as well as more information that you won't find anywhere else.

There are eBook versions for Kindle, iPad, iPhone, Android, Blackberry, and Mac operating systems. Each for only $3.99!

The paperback version will be available soon on Amazon for about $12, in case you're looking for a holiday present for that special, open-minded, friend.

The Amazon preview isn't up yet, but you can check out a preview of the entire book on Lulu.


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How Do I Love Thee? Let me check my MRI

Different types of love feel different. The love I have for my partner, my children, my parents, and even my dog are similar in some ways, but are very distinct in others. Thanks to fMRI images of the brains of people experiencing various types of love, scientists can now explain where the similarities and differences originate.

The topic isn't a new one in sexuality research circles. A Rutgers study comparing maternal and romantic love, which produced the image above, took place in 2004. The study showed that there are distinct parallels in brain activity between people experiencing the two types of love. A number of researchers turned to fMRI and other brain imaging techniques years earlier in hope of finding ways to identify the brain activity characteristic of sexual deviants like rapists and pedophiles, potentially to both reform them and prosecute them, as the case may be.

But the brain is complex. It's proven too difficult to tease out sexual criminals from the general population in a reliable way. However, a recent review paper that compares all known fMRI studies of brains in love has at least brought a few interesting aspects to light.

For one thing, love is complicated. Regardless of the type of love we're talking about, they all involve several distinct portions of the brain, including the higher-order portions typical of big brained creatures like humans. That suggests that love as we know it may not even be possible for creatures with less developed brains. Lizards and birds, it seems, are probably limited to friend-with-benefits sorts of relationships, rather than full blown love.

Not only can we love, but researchers have specifically studied three different types of love: romantic love between sexual partners, maternal love between a mother and child, and compassionate love for vulnerable strangers. All three types lead to increased blood flow, and presumably activity, in the reward portions of the brain that turn on with euphoric feelings of well being and comfort that come with orgasm, intense physical exertion, using cocaine, or being in the presence of someone we care deeply about.

In addition, both romantic and maternal love appear to reduce activity in the regions affecting anxiety while boosting activity in the portions associated with memory and happiness. There are some important differences between the two, though. For one thing romantic love switches on brain regions that are associated with self perception. At the same time, it turns off the regions that are associated with grief and loss following a relationship break-up. In other words, romance boosts self perception while helping you deal with your broken heart from your previous relationships. The best cure for a failed relationship, appropriately enough, is a new relationship.

Maternal love involves a portion of the brain that helps us tolerate physical pain. That's important, the researchers speculate, both in getting women through the trauma of birth labor and for comforting those occasional childhood booboos. That's right, momma's kiss on your bruised knee is no mere placebo - it actually changes the amount of pain you feel, according to the fMRI images.

Compassionate love for strangers is more like maternal love than romance. The interesting thing is that when test subjects were asked to intentionally stir up feelings of love for strangers, even though they were just watching videos of disabled people, the elderly, and other vulnerable folks, it reduced pain and anxiety in the test subjects themselves. It seems that loving your fellow humans isn't simply altruistic, it also makes you feel good.

None of this comes as much of a surprise, but the fMRI review can be summed up like this; if your self esteem is low or your reeling from a broken heart, a new romance will fix you up; if you fall down and go boom (or are recovering from surgery, suffering chronic pain, etc.), a hug from momma or a momma-like figure in your life can help ease the physical pain as well as making the momma figure feel better; and if you're having a bad day and just need a boost, sit on a bench, watch the people go by, and compel yourself to love them - they may be none the wiser, but you'll feel better.


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Sex in Space, Hollywood Style

It's not clear whether anyone has had actual sex in space, but that hasn't stopped filmmakers from giving us a preview.



I'm confident that it's possible, physically speaking, and will soon be an option for anyone with a few tens of thousands of dollars to blow on a trip aboard Virgin Galactic. (It seems they're already booking short flights, but it doesn't look like there's going to be much privacy on the early trips.)

In the meantime, check out the fascinating, NSFW article on io9.com compiling the greatest zero gravity sex scenes of all time. It's hot and inspiring. I can hardly wait to give it a try.

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Oral Sex Leads to Sex among Teens

Thank goodness CNN is on the job, letting us know that oral sex seems to be a precursor to sexual intercourse among teens. The original study by researchers at the University of California, San Francisco is available online in the Archives of Pediatrics and Adolescent Medicine.

From looking at the comments that readers have posted on CNN, reactions to the report tend to fall into one of three categories . . .

1. OMG, we have to stop kids from having sex! Now it looks like we can do that by stopping them from having oral sex first.

2. Duh, what a waste of money. Kids have sex in high school. Many have oral sex first, many don't. Why is anyone paying for this research?

3. Wow, that's good to know. Let's teach them how to be safe, because they're going to do it no matter what we say. Besides. exploring your sexuality as a teen is completely natural.

The researchers themselves seem to agree with answer number 1, judging by the conclusion they draw from the study. Specifically, they say

"The first 2 years of high school may be a critical age period for adolescents' vulnerability to vaginal sex initiation via oral sex behaviors. Comprehensive evidenced-based interventions and provision of preventive services aimed toward reducing sexual risk should be expanded to include the role oral sex plays in adolescent sex behavior."

I love science and scientists as a rule, but phrases like "vulnerability to vaginal sex" give me the creeps. People aren't "vulnerable to sex," like it's a disease, a drug or a crime. Other than cases of rape, which are not the focus of this study, high school students either choose to have sex or they don't.

It sounds to me like the folks who did this particular study have a bias against sex among teens. That's OK. Everyone has a right to an opinion, but published scientific research is not the place to push an agenda, especially one as loaded and sensitive as this one.

I tend to fall into the third camp. But even if you're more like the the people who share the first or second point of view, take some comfort from the fact that sexual activity in high school tends to be safer than it is later in life. Ohio State University sociologists showed 15 years ago that high school kids have a much more restrictive set of dating rules than people in the general population have.

It turns out that kids won't usually date (or have sex with) the ex-boyfriends or ex-girlfriends of their own former partners. They won't even date the old partners of their old partners' former partners. Sorry if that seems a bit confusing, but in short, they won't date someone four relationship links away or less. Older people have fewer rules about who they will and won't date. (why there's a difference is a topic of ongoing research).

Sex among adult populations forms a small world network much like the Kevin Bacon game network of Hollywood stars. As a sexually active adult, in fact, you're only a few degrees of separation away from nearly every other sexually active adult. The point is, the chances of passing or catching a disease is very high for adults who don't practice safe sex.

High school sexual connections form chains, rather than small world networks, because of the restrictive, unspoken rules that teens tend to obey. Most teens are many links away from other sexually active teens, so diseases spread poorly and can be stopped altogether if only a few of them practice safe sex.

If there is ever a good time to experiment with mutually consensual sex, it's in high school. My advice, as a parent of a son and a daughter, is relax, accept the inevitable, and teach them how to be safe. Above all, help them to understand both the risks and the benefits of sex before they grow up and jump into the much riskier adult sex world.

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