Scientific studies disprove the belief that the clitoris is the only source of women’s orgasms
The clitorocentric dogma
It’s a controversy that has lasted a hundred years.
Since the earliest studies on sexology, it was believed that the clitoris is the only source of women’s orgasms. That vaginal penetration produced orgasms only by indirectly stimulating the clitoris. Hence, the best way for women to achieve orgasm is to directly stimulate the clitoris.
For example, Alfred Kinsey wrote:
“The walls of the vagina are ordinarily insensitive. […] All of the clinical and experimental data show that the surface of the cervix is the most completely insensitive part of the female genital anatomy.” (Kinsey et al., 1953).
However, Kinsey’s own data contradict these claims: 84% of the women he examined responded to pressure in their cervix, and 93% of them responded to pressure in the anterior wall of their vagina (Jannini et al., 2012).
The idea that the vagina is not a source of pleasure was based on the observation that the clitoris has many nerve endings, while the vagina has fewer. However, the vagina has enough nerve terminals to participate in the sexual response, particularly is its most deeper parts. Besides, abundant innervation of a particular area of the body does not correspond with the intensity of the sensation elicited there, but with its accuracy. For example, the fingertips and the tongue are profusely innervated because they have fine tactile discrimination. A few nerve fibers can produce a strong sensation (pain, itch or pleasure) if their signal is amplified in the nervous system.
“Ipse dixit is a term labeling a statement, asserted but not proven, to be accepted on faith in the speaker. After Kinsey, Masters and Johnson, and Hite, this was the case of the clitorocentric dogma of female orgasm. The growing fruits of research will definitively change this paradigm.” (Jannini et al., 2012).
Vaginal orgasms and the G-spot
A large group of women felt that the idea that orgasms come from the clitoris represented their own experience. But an even larger group of women felt that it did not. They preferred to have orgasms from penetration.
“However, women anecdotally describe two types of orgasm. The clitoral orgasm obtained by the direct external stimulation is described as “warm” or “electrical,” and the vaginal one, obtained by a vaginal penetration, is depicted as “throbbing,” “deep,” and generally stronger.” (Jannini et al., 2012).
Thus, as noted in a recent article about the orgasm gap, 69% percent of women prefer to achieve orgasm through penetration. The paper cited (Blair et al., 2018) attributed this to normative sexual experiences that emphasize the male orgasm. This just parrots some political beliefs presented as feminist but that, in reality, invalidate the feelings of a large group of women, who are deemed to be sexually uneducated and brainwashed by the patriarchy.
Indeed, as I discuss in another article, the existence of vaginal orgasms is mired in political ideology. The controversy started with the claim by Sigmund Freud that women who orgasm from clitoral stimulation were psychosexually immature. In 1976, Shere Hite responded with The Hite Report, in which she used informal questionnaires to claim that the best way for women to achieve orgasm was by touching the clitoris. This eventually grew into the belief that the majority of women do not orgasm from penetration, which I debunked in a previous article.
Some sexologists, however, grabbed the banner of the vaginal orgasm. By listening to women, Beverly Whipple and John Perry rediscovered a sensitive area in the anterior wall of the vagina that swells when stimulated and can trigger orgasm and female ejaculation (Addiego et al., 1981). They named it the Grafenberg spot, or G-spot, after Ernst Grafenberg, who described it back in 1950. In fact, the G-spot was described in the Kamasutra and in Taoist texts of the 4th century, and in documents of many other civilizations (Korda et al., 2010).
Questions that need to be answered
Given the political controversy that surrounds this issue, is it possible to find scientific evidence that puts it to rest?
Since orgasm is a subjective experience, to compare orgasms form different women, or induced by stimulating the clitoris or the vagina in the same woman, looks like an insoluble philosophical problem. The subjective feelings of orgasms are qualia, conscious experiences that cannot be conveyed from one person to another.
However, scientists do not give up as easily as philosophers. They know that subjective experiences can be studied by investigating their neuronal correlates in the brain.
What we need is factual evidence that answers the following questions:
Can vaginal stimulation alone trigger an orgasm?
Is this orgasm different from the clitoral orgasm?
There are other related questions, such as whether the G-spot really exists, what is its anatomy and function, the nature of female ejaculation, and the relationship of the internal clitoris with the vagina. However, in this article in will focus on these two questions. They would establish whether vaginal orgasms are real and different from clitoral orgasms.
Functional magnetic resonance imaging (fMRI)
Today, scientists have several methods to study the activity of the brain in awake humans while they engage in different activities. They include electroencephalogram (EEG), positron emission tomography (PET) and fMRI.
fMRI is used to determine what parts of the brain are active in different conditions. When an area of the brain has increased neuronal activity, its cells consume more oxygen. This prompts an increased blood flow to this area to replenish the oxygen called the hemodynamic response. fMRI measures changes in the magnetic properties of the iron atoms in the molecule of hemoglobin of the blood when they bind and unbind oxygen. The activity of brain areas is then mapped in three dimensions. Unlike EEG, fMRI can image the activity of deep brain areas.
Women with spinal cord section have orgasms
An opportunity to answer the first question presented itself when doctor Beverly Whipple encountered the case of women with complete spinal cord transections.
The nerves that gather sensations from the genital area - pelvic, pudendal, hypogastric and lower splanchnic - carry information to the brain by entering the spinal cord at its lower segments, and then running upwards in the spinothalamic tract. If the spinal cord is severed above these lower segments, the spinothalamic tract is interrupted. All sensations below the waist, including those from the clitoris, the vagina and the anus, cannot reach the brain. Therefore, women with complete spinal cord injuries should not be able to feel their genitals and, consequently, to have orgasms.
And yet, they do! They can feel when they menstruate and when their vaginas are penetrated. They experience pleasure in their vaginas, sometimes leading to orgasm. But they cannot feel their clitoris.
How is this possible? Their gynecologists told them that they were experiencing phantom pleasure, something similar to the phantom sensations that amputees feel as coming from their missing limbs. But these women were experiencing pleasure from real penises and dildos, not phantom ones.
fMRI of women with spinal cord sections
Doctor Barry Komisaruk hypothesized that the sensations from their vaginas was carried by the vagus nerve. Unlike the sensory nerves I mentioned above, the vagus carries sensation from the internal organs directly to the brain, not through the spinal cord. ‘Vagus’ means ‘errand’ in Latin, because this nerve meanders inside of the body, carrying information back and forth from the heart, stomach, intestines and other internal organs to the brain. The bodies of the neurons that send axons in the vagus nerve are in the nodose ganglion, situated near the base of the skull. The enter the brain in the nucleus of the solitary tract (NTS).
To test this hypothesis, Komisaruk, Whipple and their collaborators carefully selected five women with complete spinal cord transections (Komisaruk et al., 2004; Komisaruk and Whipple, 2005). These unfortunate women had spinal cord injuries from bullet wounds, which provide a clean cut of the spinal cord without the messy compression produced by car crashes, falls and similar types of accidents. Compression injuries of the spinal cord make it difficult to determine if all the axons in the spinothalamic tract have been severed.
Another criterion to select the women for this study was that their spinal cord injury was above the T10 (tenth thoracic vertebra) spinal segment, to completely rule out that some branches of the genital nerves could enter the spinal cord above the injury.
First, Komisaruk and collaborators used fMRI to determine if the NTS was activated when these women self-stimulated their vagina with a dildo. If that happened, that would mean that the sensation from the vagina was carried by the vagus nerve and entered the brain at the NTS.
Sure enough, the lower part of the NTS was activated during vaginal stimulation in all five women. The NTS is organized forming a rudimentary map of the body, so its upper part correspond to the mouth and its lower part to the genitals. When the women were given a beverage with a strong taste to provide a sensation to the mouth, the upper part of the NTS was activated.
This confirmed the hypothesis that the vagus nerve carries information from the vagina to the brain independently of the spinal cord. As it turns out, the supposedly scant innervation of the vagina serves a powerful function.
Vaginal orgasms: brain fMRI of women with spinal cord injury
Three of the five women in this study experienced orgasms during vaginal self-stimulation. This offered an opportunity to use fMRI to determine the areas of the brain activated by vaginal orgasms. Since the orgasms in these women were triggered exclusively from the vagina, this may throw some light on the second of the questions above: are vaginal orgasms different from clitoral orgasms?
The areas of the brain activated by vaginal orgasms were consistent amongst the three women. Here is a list, with a short explanation of the function of each area.
Amygdala. This is the part of the brain that mediates fear and anxiety, but it is also involved in a range of other emotions, like anger and aggression. In one of the women who had multiple orgasms lasting 3 minutes, the amygdala was active only for these 3 minutes and not for the subsequent 2 minutes of fMRI recording.
Nucleus accumbens. You may have heard that dopamine release occurs in the brain when we experience pleasure. What actually happens is the activation of a ‘reward pathway’ that goes from the ventral tegmental area (VTA) to the nucleus accumbens, where it releases dopamine. Opioids, nicotine, cocaine, amphetamine and other addictive drugs activate this pathway, leading to dependence. This study showed activation of the nucleus accumbens during vaginal orgasms, which is to be expected from a pleasurable stimulus. This doesn’t mean, however, that orgasms are addictive.
Insular cortex. ‘Insula’ means ‘island’ in Latin. This is an area of the cortex that forms an island of grey matter inside the white matter of the cerebral hemispheres. The insula is associated with all kinds of emotions. It mediates the emotional component of pain that tells us that we don’t like it. It is also involved in itch, disgust, anger, trustworthiness and (of course!) sexual pleasure (Craig, 2002).
Anterior cingulate cortex (ACC). The cingulate cortex is a part of the cortex located deep inside the fissure that separate the two cerebral hemispheres. It’s one of the targets of the dopamine pathways from the VTA. The ACC, together with the insula and the somatosensory cortex, is at the end of the neural pathways that transmit pain. Its main function is to motivate us to make decisions.
Hippocampus means ‘sea horse’ in Latin because it is shaped like this peculiar fish. It is essential for memory formation and the storage of short-term memories. Its links to the amygdala mediate a role in emotions.
Cerebellum. This ‘little brain’ in the back of the skull modulates muscular contraction during movement. Its activation during orgasm may reflect the general muscular contractions and spasms during orgasms.
Paraventricular nucleus of the hypothalamus. The hypothalamus is the part of the brain that modulates the functions of the body, producing feelings like thirst, hunger and sexual desire. It is located above the pituitary gland, by which it controls the endocrine system that releases hormones in the body. Thus, the hypothalamus-pituitary-adrenal (HPA) system controls the release of adrenaline and cortisol during stress. The fact that the paraventricular nucleus is activated during vaginal orgasms is very important because it releases oxytocin into the blood. This mediates the contraction of the nipples, the uterus and the vagina during orgasm and could be responsible for the bonding effects of sex (Stein, 2009).
The sequence of activation of these brain areas is as follows. The amygdala and the insula are activated during the buildup of orgasm. Then the ACC enters the game. At the point of orgasm, the nucleus accumbens, the paraventricular nucleus of the hypothalamus and the hippocampus become activated, while the activation of the insula increases.
Clitoral orgasms: brain fMRI of healthy women
In a later study (Wise et al., 2017), the group of Komisaruk studied ten healthy women while they reached orgasm through clitoral stimulation, given by themselves or by a partner. Since they found no differences between self-induced and partner-induced orgasms, they pooled both sets of data and analyzed them together.
Unlike the study in women with spinal cord injury, the objective here was to get a fine time resolution of the events before, during and after orgasm.
I wanted to compare this study with the one on vaginal orgasms to see if there are differences in brain activation between them. Disappointingly, the authors did not do that in their paper. Hence, the conclusions I draw below are mine and not the authors’.
Not surprisingly, clitoral orgasms activated some of the same regions activated by vaginal orgasms. These include the amygdala, nucleus accumbens, insula, anterior cingulate cortex, hippocampus and cerebellum. But, in addition, there were brain regions not mentioned in the study on vaginal orgasms: the operculum, parts of the frontal cortex and the right angular gyrus.
The operculum is the area of the cortex surrounding the invagination that produces the insula. It is the main area of the brain activated in masochists when they are shown images of masochistic pain (Kamping et al., 2016). It mediates emotional responses to pain and pleasure.
The frontal cortex is the area of the brain involved in complex decision-making, setting goals and behavior inhibition. In particular, the study with clitoral stimulation mentions the orbitofrontal cortex, which is a “hedonic hot spot.”
The angular gyrus is involved in processing visual information, particularly during reading and other spatial cognition taaks. It is also involved in memory retrieval, attention and theory of mind (the capacity to imagine the mental states of other people). The angular gyrus in the right hemisphere is associate with out-of-body experiences, which the authors relate to the altered states of consciousness produced by orgasm.
One potentially interesting difference between clitoral and vaginal orgasms is in the hypothalamus. While vaginal orgasms in women with spinal cord transections activated the paraventricular nucleus of the hypothalamus, clitoral orgasms recruited the mammillary bodies instead. The mammillary bodies are involved in episodic memory. Since the paraventricular nucleus drives the release of oxytocin in the blood, this could mean that vaginal orgasms release more oxytocin and therefore leads to stronger pair-bonding.
Mental orgasms
Some women can also have orgasms with mental imagery alone, without any genital or body stimulation (Whipple et al., 1992). fMRI showed that these orgasms activated the nucleus accumbens, anterior cingulate cortex, hippocampus and the paraventricular nucleus of the hypothalamus, but not the amygdala or the cerebellum (Komisaruk and Whipple, 2005). This indicates that those four brain regions are specifically related to orgasm, while the amygdala may be related to genital sensation and the cerebellum to muscle tension.
The great variety of orgasms
The studies on women with spinal cord injury provide compelling evidence that exclusive stimulation of the vagina and the cervix can trigger orgasm. This indicates that women can orgasm from vaginal penetration alone. Whether the internal clitoris, the Skene glands, or the innervation of the vagina and the cervix are the trigger of these orgasms is an interesting question to be addressed in future articles.
There is also some evidence that vaginal orgasms and clitoral orgasms activate a few different brain areas. This supports the experience of many women, who say that orgasms triggered from the clitoris and the vagina feel different.
I am not saying that there are only two different types of orgasms, clitoral and vaginal. In fact, Komisaruk and his collaborators emphasize in their studies on vaginal orgasms that they are triggered by stimulating the vagina and the cervix, which some women consider different types of orgasms.
Orgasms can also be elicited by anal intercourse. They feel different because the anus is a sensitive erogenous zone. Given that only two thin membranes separate the rectum from the vagina, anal intercourse stimulates the anterior wall of the vagina, which can trigger an orgasm in much the same as vaginal intercourse.
Orgasms in women can also be triggered without any genital stimulation at all: by stimulating the nipples, by spankings and other forms of BDSM play, by exercise (Herbenick et al., 2021), and by mental imagery (Whipple et al., 1992). This shows that orgasms happen in the brain. Whether the stimulus comes from the clitoris, the vagina, the anus or other part of the body seems to be quite incidental.
At least, in women. Could men also enjoy this wonderful variety of orgasms?
Some men claim that they can orgasm from stimulating their prostate through anal intercourse, dildo insertion or pegging. Perhaps prostate orgasms are the male equivalent of the female vaginal orgasms. But, are men also able to climax from spankings, exercise or mental imagery?
Perhaps there is an orgasm gap, but in the opposite direction of the usually proposed. While it is true that some women have difficulty achieving orgasm, others are able to climax repeatedly and with extraordinary intensity. They would make any man envious.
Why is this important?
We may have been doing sexual education wrong by teaching women that climax should be achieved primarily by stimulating their clits.
A study using five national sex surveys in Finland (Kontula and Miettinen, 2016) found that the percentage of young women (18-34 years old) that reached orgasm during sexual intercourse decreased from 1999 to 2015. Ability to reach orgasm did not improve from the 70s to the present in any of the age groups. This is surprising, given that Finland is ranked as one of the leading countries in gender equality in the world, and that substantial advances have been made is the sexual education and liberation of women since the 70s. Why hasn’t this translated in a better ability of women to climax during sex?
It is possible that this was caused by an increase in stress and mental pressures as women incorporated into the workforce and took over more demanding careers. However, the findings in the study with Finnish women point at causes directly related to sex. Surprisingly, women who masturbated more often had less frequent orgasms during intercourse than women to masturbate less often. This contradicts the common assumption that masturbation is the best way for women to teach themselves to climax.
Perhaps too much emphasis on clitoral stimulation locks women into a single pathway to reach orgasm, instead of encouraging them to explore other erogenous zones and their great variety of possible orgasmic experiences. In this they have become similar to men, who have been taught to look at their penises as their only source of sexual pleasure.
Here are a few things that contributed to frequent orgasms during intercourse:
The importance given to orgasms.
High sexual self-esteem (“I am good in bed”).
High sexual desire and sexual motivation.
Open and easy sexual communication with their partner.
Ability to focus in the moment and mindfulness during sex.
An appreciation for sex.
Good sexual techniques.
A talent to be aroused by sexual stimulation.
Love-making sessions that are frequent and long-lasting.
Novelty.
Sexual fantasies and role-playing.
Anal stimulation.
Letting go of control.
“Women need to be encouraged to feel good about the variety of ways they experience sexual pleasure, without setting up specific goals (such as finding the G-spot, experiencing female ejaculation, or experiencing a vaginal orgasm). Healthy sexuality begins with acceptance of the self, in addition to an emphasis of the process, rather than the goals, of sexual interactions.” Dr. Beverly Whipple (Jannini et al., 2012).
References
Addiego F, Belzer EG, Comolli J, Moger W, Perry JD, Whipple B (1981) Female ejaculation: A case study. The Journal of Sex Research 17:13-21.
Blair KL, Cappell J, Pukall CF (2018) Not All Orgasms Were Created Equal: Differences in Frequency and Satisfaction of Orgasm Experiences by Sexual Activity in Same-Sex Versus Mixed-Sex Relationships. The Journal of Sex Research 55:719-733.
Craig AD (2002) How do you feel? Interoception: the sense of the physiological condition of the body. NatRevNeurosci 3:655-666.
Herbenick D, Fu T-c, Patterson C, Dennis Fortenberry J (2021) Exercise-Induced Orgasm and Its Association with Sleep Orgasms and Orgasms During Partnered Sex: Findings From a U.S. Probability Survey. Arch Sex Behav 50:2631-2640.
Jannini EA, Rubio-Casillas A, Whipple B, Buisson O, Komisaruk BR, Brody S (2012) Female orgasm(s): one, two, several. The journal of sexual medicine 9:956-965.
Kamping S, Andoh J, Bomba IC, Diers M, Diesch E, Flor H (2016) Contextual modulation of pain in masochists: involvement of the parietal operculum and insula. Pain 157:445-455.
Kinsey AC, Pomeroy WB, Martin CE, Gebhard PH (1953) Sexual behaviour in the human female. Philadelphia: WB Sanders Co.
Komisaruk BR, Whipple B (2005) Functional MRI of the brain during orgasm in women. Annu Rev Sex Res 16:62-86.
Komisaruk BR, Whipple B, Crawford A, Liu WC, Kalnin A, Mosier K (2004) Brain activation during vaginocervical self-stimulation and orgasm in women with complete spinal cord injury: fMRI evidence of mediation by the vagus nerves. Brain Research 1024:77-88.
Kontula O, Miettinen A (2016) Determinants of female sexual orgasms. Socioaffective neuroscience & psychology 6:31624-31624.
Korda JB, Goldstein SW, Sommer F (2010) The History of Female Ejaculation. The journal of sexual medicine 7:1965-1975.
Stein DJ (2009) Oxytocin and vasopressin: social neuropeptides. CNS spectrums 14:602-606.
Whipple B, Ogden G, Komisaruk BR (1992) Physiological correlates of imagery-induced orgasm in women. Arch Sex Behav 21:121-133.
Wise NJ, Frangos E, Komisaruk BR (2017) Brain Activity Unique to Orgasm in Women: An fMRI Analysis. The journal of sexual medicine 14:1380-1391.
Copyright 2023 Hermes Solenzol.