Before we get going in this section, it is worth mentioning that despite the provocative subheading, I am no Carrie Bradshaw. I could only wish to have the writing skills of a sex columnist like her—credit, of course, to Candace Bushnell, who published the book Sex and the City based on her own columns.
In a chapter discussing consensual intimate touch between romantic partners, I would be remiss, however, not to discuss sex. So far in this book, I’ve explained that we have a high number of touch receptors in sensitive areas of our body, like our hands and lips. You’d be right to guess that we have many nerve endings in more intimate regions of the body, like the genitals, too.
In his 2005 book, Touch, author David Linden provides a detailed description of the biology of sexual touch.12 He rightly notes that, like the perception of all sensory sensations, how we perceive touch in the buildup to or during sex is connected to our expectations and context. For some, having a sexual partner grab their hair in the throes of passion can be a turn-on, but if that happened while relaxing on the couch, it might get quite a different response.
Likewise, the reasons why we engage in sex aren’t always about touch. Sex is important for reproduction. It can reduce stress and anxiety, contribute to feelings of escapism and fun, and improve our self-esteem. We can seek any mixture of these goals—and others that I’ve not listed—for ourselves or our partners at different times. Having a variety of reasons for engaging in sex is often viewed as part of having a healthy sex life.13
Whatever our reasons for engaging in sexual activity, our sense of touch is intimately connected to how we experience sex. Activities like kissing and sensual touching can be part of foreplay. The act of sex itself (either alone or with another person) also involves touch to intimate body parts—and for some people, nonintimate regions too. Sure, sex is more than simply an act of touching. But touch is an integral part of the process.
To understand the role of touch in sex, maybe let’s start by asking how touch can lead to sex.
In 2012, researchers from the University of Alaska Fairbanks and Hobart and William Smith Colleges published a study called “Prelude to a Coitus: Sexual Initiation Cues Among Heterosexual Married Couples.” The research involved asking couples to keep a sex diary for two weeks, detailing sexual activity and what they or their partner did to initiate it.
Physical touch was the most-used cue to initiate sex, with 77 per- cent of the research participants reporting that they engaged in touch to start sex over the two weeks. The types of behaviors that people engaged in included a range of examples. Some spoke of “holding hands.” Others of “rubbing my breasts.” Some were even more direct, indicating that sex started by “pressing up against him” or “prodding penis between legs.”
Verbal cues like “asking to have sex” were used by 70 percent of the research participants, while nudity and undressing their partner were used by less than 20 percent of participants.
Touch was the most common signal to initiate sex for both men and women. And partners easily understood it, with 92 percent saying they recognized the intent of a tactile signal to initiate sex, and 91 percent saying it was a cue their partner often used.14
Why is touch so important to sex initiation? There are many reasons. From a sensory neuroscience perspective, intimate body parts like our genitals are sensitive to touch. The skin in areas of the body like the clitoris or the tip of the penis is full of nerve endings that respond to things like heat, cold, pain, and vibration: There’s a reason why sex toys buzz!
The signals from touch receptors in our intimate body parts during sexual activities—both sex and foreplay—are sent via specific sensory nerves to the brain. These include the pudendal nerve, a sensory nerve thought to play a role in transferring information from the clitoris or the penis, and the hypogastric nerve, which travels directly to a part of the brain stem.
The brain stem is at the bottom of our brain. It looks a bit like a stalk and connects our brain to our spinal cord. It sends signals from the brain to the body and contributes to things like breathing and heart rate (two things that can change quite a bit during sex).
There are also nerves sending signals from other areas of the body that may be stimulated during sex, like the vaginal wall, the anus, and the scrotum. In women, the pelvic nerve plays a role in carrying touch signals from relevant body parts. In men, the pudendal nerve is important for this.
The key message here is that there are common and distinct nerves carrying touch signals from our genitals and nearby regions (called perigenital regions).
The number of nerve endings that respond to touch in these areas can vary from person to person. For example, someone could have fewer nerve endings in their genitals but more in other perigenital regions, like the butt. This has led to some suggestions that individual preferences for sexual touch may connect back to an individual’s anatomy of sensory receptors in genital and peri- genital areas, or to individual differences in cross-talk between nerves associated with touch in these regions.
Put a little differently, the reason some people might enjoy certain sexual activities more than others—like more butt-centric activities—could connect back to the physiology of tactile stimulation of these regions. Although, I must admit that I do not know of any study directly investigating these hypotheses.
What is clearer, however, is the brain basis of sexual touch. We noted already that the brain stem can be activated via the hypogastric nerve. There are other brain areas connected to sexual touch. Many of these have been identified by experiments examining sexual touch and orgasm while people have their brains scanned.
Conducting brain-scanning experiments on sexual touch is a little tricky. For those of you who have been in a brain scanner, you may be able to imagine why. You lie on a bed that often feels quite cold and plasticky and are slid into what looks like a giant doughnut ring, sometimes with something that appears to be a 3-D medieval mask on your face. Then there’s a lot of noise, which some people have described as being like a jackhammer a few feet away. Not quite the description you’d hope to find in a book like Fifty Shades of Grey, unless you’re into brain scanners—in which case, enjoy!
Despite these rather unfortunate parameters, scientists have conducted several studies on sexual touch and orgasm in brain scanners like these. These often involve self-touch. Armed with sex toys, research participants have been asked to go into the scanner and stimulate their genital regions, all in the name of science.
Much of the research on the neuroscience of sex and orgasm has been pioneered by Barry Komisaruk and Beverly Whipple, of Rutgers University in New Jersey.15 Over the years, their research has shown that sexual touch and orgasm are related to extensive brain activity. As Komisaruk explained in an article published by the American news website Vox in 2015, when it comes to orgasm, “more than thirty major brain systems are activated. It’s not a local, discrete event. There’s no ‘orgasm center.’ It’s everywhere.”16
Patterns of brain activity during genital stimulation and orgasm can be quite similar in men and women. The somatosensory cortex is often involved in the buildup to orgasm, likely reflecting responses to genital touch.
But other brain regions are also important.
One brain area, called the hypothalamus, is thought to respond to arousal through sexual activities like touch. It contributes to the functioning of a range of hormones and neurotransmitters associated with arousal and positive responses to sexual stimulation. Some hormones that are thought to be released include dopamine, testosterone, and noradrenaline.
Changes in brain regions within the limbic system—like the amygdala and hippocampus—are thought to reduce fear and aggression before orgasm. At the same time, it is suggested that changes in prefrontal brain regions contribute to the deactivation of brain networks involved in self-evaluation, reasoning, and impulse control. All these support a reduction in fear and anxiety, which is often considered essential in leading up to orgasm.
The experience of orgasm itself has been linked with activity in regions of the brain associated with feelings of euphoria, while the release of oxytocin and dopamine contributes to the relaxing pleasure connected with experiencing orgasm.
The fact that orgasm can cause the release of hormones like oxytocin and dopamine speaks to another important message: Orgasms can offer benefits to our physical and mental health.17 This is true whether the experience comes with a partner or simply by going solo. Some benefits connected to orgasm include better mood, better sleep, better skin, and better immune response. Put crudely, science tells us that orgasm can have many advantages: It gives us a nod to enjoy some consensual or solo fun; it’s good for us, after all.
Excerpted from Touch Matters: Handshakes, Hugs, and the New Science on How Touch Can Enhance Your Well-Being by Michael Banissy. Published by Chronicle Prism, an imprint of Chronicle Books. Copyright © 2023 by Michael Banissy.
Touch Matters is available from Amazon and Bookshop.