The human sexual response cycle is a nifty little way of outlining the physiology behind sexual encounters. The first model was devised by William H. Masters and Virginia E. Johnson, two experimentalists who carved the unusual way for laboratory testing of sexual activity. They broke down the physiological reactions we have to sexual stimuli into four stages: excitement, plateau, orgasm, and resolution. This pretty much follows a trend similar to the oversimplified exoskeleton of a work of fiction your middle school teacher taught you. Not unlike the exposition-rising action-climax-falling action schema of a plot line, the phases of the sexual response cycle detail what is going on each step of the way—and allow us to discern where we may have strayed from the beaten path.
The first little stirrings of sexual arousal. The incipient rising action of a novel. Usually when Harry’s scar starts to prickle. Excitement can be engendered with physical stimulation, visual input, or any degree of adolescent imagination. Perhaps you’re bored in class. Maybe there’s a lot of nether-region friction between your clitoris and lacy underwear, plus you’re bored in class. Or more excitingly, maybe you’re tangibly interacting with another human being, doing things like kissing, heavy petting, et cetera. Whether you’re engaging in sexual conduct with a fellow mortal or harmonizing with your hand, your muscles are tensing a little, your heart rate, respiration, and blood pressure are piqued, and nipples salute the world. As excitement gets, well, more exciting, other signs appear. For females, the most obvious is vaginal lubrication, but there are more or less superficial symptoms, like swelling of the clitoral glands. Lengthening and widening of the vaginal canal, à la childbirth. Labia separate and flatten into what I imagine is a happy genital grin as breasts balloon with a sanguine rush. For males, _______
The plot thickens. This is generally the point in a novel or TV show where you become way too emotionally invested in the characters, and being interrupted makes you want to do the Darth Vader-ishly “NOOOO!” Similarly, bad things happen if your plateau phase is somehow truncated by an external intrusion that clearly doesn’t get what is going on. “Plateau” is sort of a misleading term because rather than leveling off, your physiological responses to sexual stimuli mushroom in quantum leaps. Bodies stiffen with myotonia, the sort of coital version of rigor mortis, as erogenous zones brace for impact. Your heart rate, respiration, and blood pressure go haywire, producing a full-body sex flush, and for women, engorgement of the breasts and labia. In females, the orgasmic platform arises magisterially out of the effervescent wetness like Mt. Olympus toward the sun, priming the body for orgasm. The orgasmic platform is really just the tissues of the outer third of the vagina that have become swollen from stimulation. During this stage, which lasts only about thirty seconds to three minutes, erections experience lateral growth and take on a nice sunset color. Testicles similarly expand to about 50% of their original size.
The best part! Our raison d’être! The apogee of the response cycle! Also, very sadly the shortest phase, coming in last at just a few seconds. As hypertrophic organs clash and hormones surge, a little miracle called the orgasm occurs. The orgasmic platform contracts in .8-second intervals (the same rate, it turns out, as a male’s contractions) for about five to twelve contractions. Physiological symptoms include involuntary muscle spasms throughout the body, sensory blunting, and heart rate and respiration maximization. Females can experience a wider range of patterns than males in their climaxes: sometimes it’s a simple release of tension, other times it’s a flood-like apocalypse with Richter-scale contractions. Male contractions culminate in ejaculations out of the urethra, although occasionally ejaculation can happen sans orgasm (in an interesting testament to our bodies’ exquisitely engineering functionality, the bladder sphincter closes off to prevent the ejaculation from backfiring into the bladder).
Ah. The stage where divergence of interests becomes painfully clear: women want to cuddle; men want to sleep and wake up to a juicy sandwich. Luckily, there’s an almost entirely physiological explanation for this phenomenon. After males orgasm, they are physically incapable of any sexual activity immediately after—“immediately after” ranging from a few minutes or so to a couple days. Females, on the other hand, don’t experience this refractory period and are physically, though perhaps not emotionally, still rearing to go. This is why women can have multiple orgasms…and men can’t. Penises, accept defeat. Physical characteristics of the resolution phase include feelings of satisfaction and relaxation—a sweaty après-ski sheen. Freedom from the full-body-bind of myotonia and return of physiological symptoms to the pre-excitement state (this usually takes within ten to thirty minutes). Feelings of soporific exhaustion. Emotional outbursts. Sometimes even a human connection.
These phases may seem pretty obvious, but having this neat blueprint that approximates what goes on before, during, and after sexual activity helps address issues of sexual dysfunction. Each of these phases doesn’t obligatorily lead to the next. You can oscillate back and forth on the multi-pronged swing of the sexual pendulum, making the cycle more likea smooth continuum of fluctuating sexual desire or non-desire where each partner may reach each stage at a different time. Sexual dysfunction can occur when a person is stuck at one stage but wants to proceed to the next, like the incapacity to orgasm due to some deep-dwelling psychological strangleholds. The trouble could also lie, as many women find, with simply putting the cycle in motion. Pacing and timing problems are common and can be looked at through the lens of the sexual response cycle.
A problem faced by many women is prolonged sexual excitement without the happy ending. Too much time spent in sexual limbo causes pelvic congestion, which can lead to pain or discomfort. This condition is exacerbated if vaginal penetration ensues before the vagina has been properly lubricated. Linked to this issue is the trouble women have orgasming without direct clitoral stimulation—because the clitoris is more sensitive and the vaginal walls have a very specific sensitivity, it’s harder to achieve an orgasm from intercourse. And since intercourse is the preferred medium of release for heterosexual men, the sexual response cycle is likely to stall for women having heterosexual relations. Females’ sexual response cycle is thus more “complex and problematic,” according to Dr. Nelson Soucasaux, a Brazilian gynecologist, in the sense that it hinges on a lot of different, specific factors.
Alternative Models of the Sexual Response Cycle
Other versions of the sexual response cycle include emotional phases such as desire. Shannon Bertha, PhD, insists on including desire as a preliminary phase since many sex therapy patients often report feeling completely desire-deficient yet respond normally when they “force” themselves to have intercourse (much like dragging yourself to the gym—annoying but rewarding). Involuntary concupiscence can also be a problem, at least in my experience—little to no emotional desire, but your vagina clearly has other thoughts (however, this might just be the newest form of poor prioritizing my body has evolved as I’ve immunized myself against other forms of procrastination, like Facebook, using website-blocking apps like SelfControl). Anyway, if we separate desire and the other responses into different phases, we can discern which stimuli affect us in the desire phase versus in the other phases. Helen Singer Kaplan’s three-stage model of the cycle involves desire, excitement, and orgasm, which is perhaps a more fluid and less rigidly structured way of representing both physiological and emotional responses.
Personally, I’d like to propose a sub-phase of phase four (Resolution) called vulnerability, where, as if a sexual saturnalia weren’t enough, you (or at least I) invariably succumb to the baser temptations of life like having a classic post-coital cigarette or an obscene gastronomic adventure. I’m not sure what it is about sexual activity that makes us want to stuff our faces, but hopefully it has a nice little absolving physiological explanation.
Finally, a parting caveat: beware of spectating. Now that you know everything about the sexual response cycle, it’s time to forget about it so you don’t become the third-party observer to your own fun.