Science of Sex: Dual Control Model

August 13th, 2017

Welcome to the fifth installment in a new feature on Of Sex and Love: Science of Sex. In this feature, I plan to discuss the science of sexuality in an easy-to-digest format that’s accessible to the casual reader. I will also follow up with some extended reading material for people who want to know more about the subject of each post.

Enjoy!

dual control model of sexual desire

I’ve been interested in the dual control model since I first read about it in Emily Nagoski’s book Come As You Are, which I highly recommend but apparently never got around to reviewing. The dual control model was first proposed by Bancroft and Janssen in the early 2000s. This theory is relatively new, but it’s become accepted because it explains desire for many people.

The dual control model explains why desire is more complicated than we’ve been led to believe. It’s not just about what turns us on (our Sexual Excitation System (SES)). Turn offs (Sexual Inhibition System (SIS)) are also as important, and things that arouse you and detract from your desire happen at the same time. Whether you want to have sex is the result of this equation.

SESes (accelerators) can include being attracted to someone, sexy books, music or movies, someone who smells good and, in a few people, stress. SISes that put the kibosh on your arousal might be needing to shower or brush teeth (or needing the same from your partner), having kids or roommates home in the house, dissatisfaction with a relationship, being self-conscious about your body, or any kind of stress. Mood can be a brake, and women are more sensitive to mood when it comes to desire.

The original surveys were given to men and focused on issues with erectile dysfunction. Bancroft and Janssen divided inhibitors into type types for men: SIS1 refers to performance anxiety while SIS2 is inhibition due to possible consequences of sex. Since then, a survey with modified questions has been given to women.  Results indicated that feelings about relationships are especially important to a woman’s desire.

Nagoski’s book is geared toward women, and the dual control model is especially helpful for women who can’t figure out why they don’t want sex more — or even if that means something is wrong with them (hint: there’s not). The dual control model specifically explains why pressing down the gas pedal isn’t enough for many people to want more sex. They must let up on the brakes (inhibitors/turn offs).

I found this explanation especially intriguing because it affects everyone. Dr. Nagoski does discuss this in Come As You Are, mentioning that men tend to have more sensitive accelerators and less sensitive breaks than women. The things that want to make them have sex are many and powerful while the things that make them hesitate are fewer and weaker.

I was eager to apply the dual control model to myself. As best as I can tell, I have more sensitive accelerators than many women but more sensitive brakes than most men. I think many people will benefit from analyzing their desire though the filter of the dual control model.

Interestingly, bisexual women tend to have higher levels of desire than straight women according to the dual control model. I’d like to see how different demographics stack up to straight men and women.

Further Reading

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Science of Sex: Genetic Sexual Attraction

July 15th, 2017

Welcome to the fifth installment in a new feature on Of Sex and LoveScience of Sex. In this feature, I plan to discuss the science of sexuality in an easy-to-digest format that’s accessible to the casual reader. I will also follow up with some extended reading material for people who want to know more about the subject of each post.

Enjoy!

science of sex genetic sexual attraction

Genetical sexual attraction is the phenomenon where two people who are biologically related but first meet in their adulthood as strangers and experience sexual attraction to one another. Genital sexual attraction, or GSA, can occur between siblings or a child and a parent.

Adoption is the main environment of GSA, and changing laws allowed many adopted people seek out their biological families, which can lead to one or both parties experiencing genetic sexual attraction. The attraction comes on suddenly and strongly and the senses of hearing, touch and smell play a significant role. To many, the term “attraction” isn’t strong enough. It’s an obsession or an addiction with the accompanying compulsions and inability to stop thinking about their attraction.

Cause of Genetic Sexual Attraction

Part of the draw might be meeting someone who shares similar personality traits and appearance, a result of genetics. This can lead people to a frenzied state much like new relationship energy — except they’re related. There is also an argument for an attraction based on similar genes, specifically having similar phenotypes (traits an individual of a species has based on gene and environmental interaction), which would obviously be the case for two people who are related.

People who experience genetic sexual attraction often feel confused and shame as they grapple attraction for their family members. People who try to deny their thoughts and feelings may wind up even more entrenched due to the ironic process theory (your brain must keep thinking about any subject you’re trying to avoid to monitor whether it’s thinking about it). In some instances, attraction occurs for only one of the people, and that person may pursue the object of their desire compulsively.

When the attraction is equal, the parties may engage in sexual activities or intercourse. GSA sex seems to occur most frequently between siblings. Some couples have been arrested and tried for incestuous relationships. These laws strive to reduce offspring from an incestuous relationship because those children are likely to suffer severe birth defects or mental disabilities.

Some people who have developed romantic relationships with their biological family members are fighting for the right to marry the people that they have only known as an adult – and never as a family member.

There are reported cases of GSA among adults who only discovered that they were related to their romantic/sexual partners after developing a romantic/sexual relationship.

Incest Taboo

It might be more telling to understand where the taboo incest comes one. It may be due to the Westermarck effect,  also known as reverse sexual imprinting, which endeavors to explain the incest taboo by showing that people develop a sort of sexual immunity to their family members after living with or near them during their developing years.

Dr. Maurice Greenberg performed a study in 1992 and discovered that many people who experienced genetic sexual attraction to a biological family member shared typical disgust toward incestuous relationships with their adopted families, which led him to differentiate between incest and GSA.

However, we also know that sexual imprinting (in which someone chooses a mate similar to a parent) exists and can occur in adoptive families as well as biological ones.

Frequency of GSA

One study suggests that it happens in as many of half of those instances of adult family members meeting for the first time while another study found that every informant had experienced genetic sexual attraction and one-third of those people had engaged in sex with a bio family member.

A few professionals and communities have developed to provide support to those people who might be struggling, either because they’re experiencing unwanted GSA or because they’ve chosen a relationship with a biological family member.

One notable name is Barbara Gonyo, the woman who first coined the term genetic sexual attraction after herself experiencing it toward her son. While he didn’t return the attract and Gonyo eventually moved on from her obsession and now provides counseling services to others like her.

Like any attraction, the flame can wither and die. Barbara has been able to overcome the feelings of attraction to her son, who is now married.

Further Reading

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Science of Sex: HPV and the HPV Vaccines

June 17th, 2017

Welcome to the fourth installment in a new feature on Of Sex and Love: Science of Sex. In this feature, I plan to discuss the science of sexuality in an easy-to-digest format that’s accessible to the casual reader. I will also follow up with some extended reading material for people who want to know more about the subject of each post.

Enjoy!

Science of Sex HPV

Human Papilloma Virus in a Nutshell

HPV is the virus that causes genital warts, but just because you don’t have any symptoms doesn’t mean you don’t have HPV. It’s one of the most common sexually-transmitted infections with over 200 strains (strains 16 and 18 cause over two-thirds of all cervical cancer while low-risk strains 6 and 11 cause most warts). Over 80 million people or about 1 in 4 people have it. It’s easy to transmit through skin-to-skin contact, so even using condoms may not prevent HPV. The CDC advises that ‘nearly all’ men and women will contract HPV in your life, and it’s likely that many people don’t even know they have it.

HPV doesn’t just cause warts. It can lead to irregular PAP smear results for women and cause cervical cancer (HPV can also be the culprit for other cancers, including that of the throat and anus). Those results can lead to a woman getting tested for HPV, but there is currently no test for HPV in men who have an asymptomatic strain (some sources indicate that a test does exist but it’s expensive and invasive).

Treatment of HPV may mean doing nothing at all. Most cases clear up within two years, but this isn’t always the case.

The HPV Vaccine

A vaccine for several of the most common strains of HPV, including some that cause cervical cancer, Gardasil, became available about 10 years ago. There are now three different vaccines for HPV available (Cervarix, quadrivalent Gardasil, and 9-valent Gardasil-9), the latter of which cover more strains of HPV than the original. One study concludes that HPV vaccines can prevent “most” invasive cervical cancers (around 70% of cervical cancer for the 9-valent vaccine and 66% for original Gardasil) as well as some oral cavity, penile, laryngeal and vulvar cancers. These vaccines are at least 90% effective at blocking those strains.

The vaccines consist of three doses that you can take between ages of  11 and 27 (for women) or 21 (for men). Younger patients may only need two doses. Even if you can’t take all shots within this time frame, you’ll still benefit from at least one dose. Similarly, the vaccine is still beneficial if you’ve already become sexually active, but it’s more beneficial if administered before sexual activity. In this case, the younger the better.

Although at first recommended for girls, HPV vaccines are beneficial for boys who can contract and transmit HPV. But it’s less likely that a male will no if he’s HPV-positive, which means he’s more likely to transmit it to a partner.

Still, fewer boys than girls are being vaccinated (12% of boys had received all three doses compared to 36% of girls in 2013), and vaccination occurs at a later age. Fortunately, vaccination rates have increased through the years, perhaps as no serious side effects have arisen over the years and the efficacy of the vaccines have been proven. For girls, infections by strains of HPV that the vaccine prevents has dropped 64% since 2006.

Let’s hope that vaccination rates rise, gaps close and strides can be made to cover more strains of HPV in future vaccines!

Further Reading

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Science of Sex: Birth Control

May 13th, 2017

Welcome to the third installment in a new feature on Of Sex and Love: Science of Sex. In this feature, I plan to discuss the science of sexuality in an easy-to-digest format that’s accessible to the casual reader. I will also follow up with some extended reading material for people who want to know more about the subject of each post.

Enjoy!

science of sex birth control

Barrier methods of birth control, including condoms, cervical caps, diaphragms and the sponge block sperm from moving through the cervix to the uterus, where it would otherwise fertilize an egg. If the barrier becomes compromised, say, by a pinhole or friction, it’s less effective.

Barrier methods are sometimes combined with spermicide in the form of nonoxynol-9. As I mentioned in my previous Science of Sex post on lube, nonoxynol-9 is detrimental to sperm, but it can also have a caustic effect on your sensitive vaginal tissues and can even make it more likely to contract an STI.

Hormonal birth control varies, however. The regular birth control pill, which contains a combination of both estrogen and progestin, a synthetic form of progesterone.

During a woman’s menstrual cycle, estrogen peaks, signaling for her pituitary gland to release other hormones (follicle stimulating hormone and luteinizing hormone, to be specific). This leads to the release of an adult egg, which can be fertilized if sperm makes its way to the egg.

When a woman is on combination birth control, the hormones create a balance and that estrogen spike is prevented from occurring, so no egg is released. Progestin also makes a woman’s uterine lining less ideal for hosting a fertilized egg. Other hormonal birth control methods, including the patch and NuvaRing, work in a similar way.

However, not every form of hormonal birth control contains a combination of hormones. The progestin-only pill (called a POP or mini-pill) lacks estrogen as the name suggests. These pills are less effective than combination birth control. Because they have no estrogen, these forms of birth control may allow more breakthrough bleeding than combination birth control.

Progestin-only birth control may be prescribed to women who are breastfeeding (breastfeeding naturally prevents ovulation, but the mini-pill in addition to breastfeeding is more effective than breastfeeding alone) as well as those who suffer from migraines. Combination pills were once believed to contribute to migraine headaches; however, more recent science suggests that this may not be the case and that combination BC may even help prevent migraines. Nevertheless, taking combination birth control if you already experience migraines with auras might contribute toward strokes.

The Mirena and Skyla IUDs (in the form of levonorgestrel), Implanon, and Depo-Provera are progestin-only BC methods.

Most birth control falls into the category of barrier or hormonal methods, but copper IUDs alone take a different route. Copper IUDs (Paragard in the US) are sometimes known as just a copper-T or coil and work by releasing small amounts of copper into your blood stream. Copper is an effective spermicide without the side effects of nonoxynol-9, damaging sperm so to prevent fertilization. Copper IUDs may also prevent ovulation.

Further Reading

Did you enjoy the second installment of Science of Sex? Do you have further questions or suggestions for next month’s subject? Leave me a comment!

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Science of Sex: Lube

April 11th, 2017

Welcome to the second installment in a new feature on Of Sex and Love: Science of Sex. In this feature, I plan to discuss the science of sexuality in an easy-to-digest format that’s accessible to the casual reader. I will also follow up with some extended reading material for people who want to know more about the subject of each post.

Enjoy!

science of sex lube

I am not the first person to write about lube, and I doubt I’ll be the most effective. But lube is so interesting from a scientific viewpoint, and I believe we can never talk about it enough.

Lube should make sex better, but it doesn’t always. For example, lubes that contain the spermicide nonoxynol are quite abrasive to sensitive tissues, resulting in micro-tears that actually facilitate the transfer of infections. Multiple studies have shown that Nonoxynol-9 contributes to HIV transmission.

Osmolality

Depending upon its osmolality, the measurement of particles per KG in a solution, lube may be doing unseen damage to your vagina or anus that increases the likelihood of an infection, too. Many lubes have a much higher osmolality (greater than 1,000 mOsm/Kg) than the vagina (~275 mOsm/Kg) or anus meaning there are more particles in the lube than the tissue it comes in contact with.

Osmolality is also important when it comes to sperm, which have a different measurement than vaginas, anuses, saliva and many lubes. By default, nearly all lube proves to be an inhibitor to sperm, so you’ll want to look for sperm-friendly lube when it comes to

Lube pH

If your lube has a pH that differs from your body’s natural pH (between 4.5 and 7 for most vaginas; pH varies during your cycle and life), you might find yourself dealing with a yeast infection while your body seeks balance.

Other Problematic Ingredients

And personal lubes that contain L-arginine, which is typically used to encourage sensitivity and arousal, can cause a herpes breakout. Sensation lubes (warming or cooling) typically rely on menthol or capsaicin to produce the desired effect, and every body responds to these chemicals differently.

Numbing agents such as lidocaine or benzocaine are sometimes found in anal lubricants. However, experts recommend against numbing the area because it both reduces pleasure and makes it harder to tell if you’re being too rough, which could lead to damage.

Lube and Your Toys

Even if lube is good for your body, it may not be compatible with your toys, which is the case with low-quality silicone lube and silicone toys. Using them together can cause an interaction that increases the porosity of your silicone toys, so they’re not as body-safe as they once were.

Further Reading

Did you enjoy the second installment of Science of Sex? Do you have further questions or suggestions for next month’s subject? Leave me a comment!

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Science of Sex: Conditioning

March 11th, 2017

Welcome to the first post in a new feature on Of Sex and Love: Science of Sex. In this feature, I plan to discuss the science of sexuality in an easy-to-digest format that’s accessible to the casual reader. I will also follow up with some extended reading material for people who want to know more about the subject of each post.

I hope you enjoy. 

Science of Sex -- Conditioning

We all learned about Pavlov, his dogs and classical conditioning in school. By associating a neutral stimulus (the ringing of a bell) with a desired reward (food), Pavlov was eventually able to condition dogs to salivate at only the sound of the bell, even when there was no food in sight.

Much like food conditioning, sexual conditioning exists. However, many people first stumble across their capacity for conditioning quite by accident. Whether you masturbate to hardcore porn during your formative years and become unable to get off any other way or you realize that you’re physically turned on at the sight of a bright red lipstick that your partner wears specifically for sex, you’ve been conditioned.

Human’s aren’t the only animals capable of sexual conditioning. In fact, humans may be less prone to this type of conditioning than other animals. People who higher sex drives who more easily respond to sexual stimuli are the most likely candidates to become sexually conditioned, whether by accident or design. Most studies focus on men, who may be more likely to become sexually conditioned; however, women can experience it, too.

Upon discovering sexual conditioning, some people like to experiment it. BDSM practitioners sometimes employ sexual condition as it’s especially helpful to force someone to orgasm on command. You can certainly play around with sexual conditioning without being kinky, however.

Attempting to sexually condition someone without their knowledge may cross fall into consensual gray area. And classical conditioning has been used for nefarious purposes: specifically to change a person’s sexual orientation. The process, known as conversion therapy, attempts to change a person’s orientation with stimuli such as electricity or nausea drugs. No reputable studies show that this type of conditioning is successful, and one proponent of conversation therapy who wrote a controversial paper about it has since changed his stance and offered an apology to the gay community.

Finally, PTSD because of past trauma can lead to conditioned behavior in otherwise neutral environments because of fear conditioning. This is one reason why it can be difficult for survivors of assault to engage intimate behavior after the assault.

Fortunately, negative conditioning and fear conditioning may be reversed through a process known as counter-conditioning.

Although classic conditioning used for sexual purposes is possible and can be fun, we must address the ethical implications as well as the limitations of sexual conditioning.

Further reading on conditioning and sexuality:

Did you enjoy the first installing of Science of Sex? Do you have further questions or suggestions for next month’s subject? Leave me a comment!

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