What a terribly embarrassing topic! I write this secluded, with little prospect of anyone else reading it, and I can feel myself blushing just typing the word masturbation.

But perhaps this will dispel it: I masturbate. You masturbate. We do it roughly daily, and usually once a week. If we don’t, it’s because we’re having sex with someone, or are incapable. We do it thinking of specific persons, we do it thinking of nothing in particular, we do it to porn, we do it without. Males masturbate, females masturbate. I don’t know about the rest of us, but I suspect they do something.

Now that’s said, masturbation is an interesting topic from a practical viewpoint. It is a mechanism that reaches right into one of the most primal and powerful drives. It’s no surprise that it’s a daily or even more frequent occurrence. Indeed, I have difficulty describing even those people who masturbate, say, 7 or 8 times a day (the compulsive masturbators) as suffering from a sort of addiction; I feel as if I’d then have to begin analyzing air addiction (every minute, even!) or glucose addiction (some people eat multiple times a day!) or melatonin addiction (some people sleep several times a day!).

If we adopt this cold-blooded or practical view, different questions arise. How do we best manage masturbation? What is the optimal schedule? When should we masturbate? Right before we go to sleep seems like a good idea, but perhaps masturbation is like tea in the morning - a good way to start the day.

For that matter, perhaps if we are disciplined, the ideal would be no masturbation whatsoever. Not because of any moral or cultural reason, but because it lets us get more important things to do. I am aware of no hard facts on the topic, but consider: one of the explanations postulated to explain the commonplace of the great artist who is gay is that such an artist can find little to no sexual satisfaction conventionally, and their masturbating is insufficient for a lifetime; thus, they divert their libido into other channels such as their art. And certainly they are not spending hours acquiring and consuming pornography or lovers. Normal heterosexuals can find conventional satisfaction, and thus their energy is diverted. A small difference perhaps, but the difference might compound over the years. And art is often a winner-take-all scenario. And one wonders about religion - celibacy is a common trait in religion, and usually is only applied to those the religion wants to be really effective at being religious like monks and priests… (Religions which enjoin celibacy for all - like the Shakers - do very poorly, but ones which reserve it for select groups are often among the most successful, Catholicism coming to mind. Counter-examples would be Islam and Judaism, neither of which seems to have common celibacy but the former of which has been quite as successful as Christianity in proselytizing itself.)

The suggestion that ceasing masturbation would assist in one’s endeavors is certainly not original (I first noticed it in Cryptonomicon, but I have seen it elsewhere). I am not certain what lesson to draw from my own experience. I once, on a lark, stopped masturbating for 2 weeks - much as I sometimes stop consuming caffeine, that I might see what my life is like without. (My fear is that I might become so accustomed to caffeine that I cannot function normally, like some sad cases I have seen.) The first week saw little change, besides some restlessness on my part. But midway through the second week, I happened to pass through the local shopping mall on some errand or other, and I was shocked. I couldn’t stop looking at all the girls and women! Obsessively I stared, undressing them in my mind and further. Before this, I looked at women, certainly, but there was never an issue of whether I could stop. But this time was different; even averting my gaze did not permit me my equilibrium. I hurried out, with considerable food for thought. I did not notice any increase in my output or motivation.

Was the issue my age and hormones? My lack of romantic attachments? A flaw in my implementation? An insufficient trial period?

Perhaps the issue was that I had nothing in particular to do; the examples of great artists and the two relevant characters in Cryptonomicon all had difficult goals and considerable drive.

I suspect this might be like the spaced repetition effect for learning; real and effective, but so subtle it requires quantification and long-term consideration.

Potential counter-objection: not masturbating is exercising willpower, sometimes considerable willpower, to refrain from a pleasurable activity. Willpower may be depletable (see the blood-sugar footnote in DNB FAQ). see also http://www.nytimes.com/2011/08/21/magazine/do-you-suffer-from-decision-fatigue.html?pagewanted=all

Masturbation too common to really fit this picture?

The science is straightforward. Whenever a behavior is common in the animal kingdom, biologists suspect it has an adaptive function. That is, the behavior enabled individual animals to survive better and leave more offspring than animals that did not engage in the behavior. As a result, genes for the behavior spread throughout that population until it became essentially ubiquitous. And so it is with autoeroticism, which is common-really common. As the Science in Seconds blog noted this week, what with spanking the monkey, charming the snake, and freeing willy, a remarkable number of the slang terms for pleasuring oneself refer to animals. That reflects reality: the practice has been documented in Japanese macaques, gibbons, baboons, chimps, elephants, dogs, cats, horses, lions, donkeys, and walruses that manage to flog the bishop with their fins. (Bonus for clicking on the blog link above: excellent photo of an elephant in flagrante dilecto.)…

1. Masturbation might remove old, worn-out, broken sperm from the reproductive tract. That would increase the fraction of healthy, speedy sperm, improving a male’s chance of becoming a father. In humans, masturbation increases sperm quality (by promoting younger sperm) without affecting sperm numbers in the female reproductive tract, notes biologist Jane Waterman of the University of Central Florida in a new paper in the journal PLoS One. As far back as 1993, biologists had observed that masturbating decreased the number of sperm a man delivered the next time he had sex with his partner, but not the number of sperm the woman retained. They concluded that masturbation is a male strategy to increase sperm fitness. Research presented at a science meeting last year offered support for the fitter-sperm idea. Ejaculating daily for seven days improved sperm quality as measured by the amount of DNA damage: levels of damage averaged 34 percent on a standard measurement index after three days’ abstinence, but after a week of … um, non-abstinence, the level of damage dropped to 26 percent, in the fair range for sperm quality. Looking only at men whose sperm damage decreased (in a few, damage got worse for some reason), the average damage level fell to just under 23 percent-putting them in the good range. In addition, sperm motility rose significantly. Result: healthier and possibly more babies.

…4. Masturbation can serve a hygiene function. According to this idea, males engage in autoeroticism because it cleans the reproductive tract and reduces the chance of acquiring a sexually transmitted disease from a female that he mated with and who had other recent partners. Result: a lower incidence of STDs, better sexual hygiene, more mating, more babies.

The STD function is what Waterman inferred about masturbation after she spent 2,000 (!) hours observing the Cape ground squirrel (Xerus inauris) of Namibia. As she explains in PLoS One, an oral masturbation was recorded when a male sat with head lowered and an erect penis in his mouth, being stimulated with both mouth (fellatio) and forepaws (masturbation), while the lower torso moved forward and backwards in thrusting motions, finally culminating in an apparent ejaculation. The behavior was much more frequent on days when females were fertile, and mostly occurred after mating. That would seem odd, since it wastes huge numbers of sperm just when they have the best chance of finding a willing egg. Odd, too, is the observation that males masturbated more when their mate had had a lot of other suitors (female Cape ground squirrels mate with up to 10 males in their three-hour fertile period). But there is one explanation that makes sense of a behavior that occurs after mating, and more often when a male has mated with a particularly promiscuous female: masturbation is a way for males to reduce the chance of infection, since saliva has antibacterial properties. Since STDs can destroy fertility, sexual hygiene through masturbation is a way for male squirrels to keep making babies.

The Scientific Case for Masturbation, Newsweek

Fertility in East Asia has fallen from 5.3 children per woman in the late 1960s to 1.6 now. In countries with the lowest marriage rates, the fertility rate is nearer 1.0. That is beginning to cause huge demographic problems, as populations age with startling speed. And there are other, less obvious issues. Marriage socialises men: it is associated with lower levels of testosterone and less criminal behaviour. Less marriage might mean more crime.

https://www.economist.com/node/21526350?fsrc=scn/tw/te/ar/asiasloneyhearts

Although animal researchers established the role of testosterone as a social hormone decades ago, the investigation of its causal influence on human social behaviors has only recently begun. Here, we review and discuss recent studies showing the causal effects of testosterone on social interactions in animals and humans, and outline the basic neurobiological mechanisms that might underlie these effects. Based on these recent findings, we argue that the role of testosterone in human social behavior might be best understood in terms of the search for, and maintenance of, social status.

The role of testosterone in social interaction

Testosterone, that most male of hormones, takes a dive after a man becomes a parent. And the more he gets involved in caring for his children - changing diapers, jiggling the kid on his knee, readingGoodnight Moon" for the umpteenth time - the lower his testosterone drops. So says the first large study measuring testosterone in men when they were single and childless and several years after they had children. Experts say the research has implications for understanding the biology of fatherhood, hormone roles in men and even health issues like prostate cancer…The study, experts say, suggests that men’s bodies evolved hormonal systems that helped them commit to their families once children are born. It also suggests that men’s behavior can affect hormonal signals their bodies send, not just that hormones influence behavior. And, experts say, it underscores that mothers were meant to have child care help. This is part of the guy being invested in the marriage, said Carol Worthman, an anthropologist at Emory University who also was not involved in the study. Lower testosterone, she said, is the father’s way of saying, " I’m here, I’m not looking around, I’m really toning things down so I can have good relationships. What’s great about this study is it lays it on the table that more is not always better. Faster, bigger, stronger - no, not always.…Testosterone was measured when the men were 21 and single, and again nearly five years later. Although testosterone naturally decreases with age, men who became fathers showed much greater declines, more than double the childless men. And men who spent more than three hours a day caring for children - playing, feeding, bathing, toileting, reading or dressing them - had the lowest testosterone…Other studies have suggested, though not as definitively, that behavior and relationships affect testosterone levels. A study of Air Force veterans showed that testosterone climbed back up after men were divorced. A study of Harvard Business School students found that those in committed romantic relationships had lower testosterone than those who were not. Another study found that fathers in a Tanzanian group known for involved parenting had low testosterone, while those from a neighboring culture without active fathering did not. Similar results have been found in birds and in mammals like marmosets, said Toni Ziegler, a senior scientist at the Wisconsin National Primate Research Center.

In Study, Fatherhood Leads to Drop in Testosterone; referencing:

In species in which males care for young, testosterone (T) is often high during mating periods but then declines to allow for caregiving of resulting offspring. This model may apply to human males, but past human studies of T and fatherhood have been cross-sectional, making it unclear whether fatherhood suppresses T or if men with lower T are more likely to become fathers. Here, we use a large representative study in the Philippines (n = 624) to show that among single nonfathers at baseline (2005) (21.5 ± 0.3 y), men with high waking T were more likely to become partnered fathers by the time of follow-up 4.5 y later (P < 0.05). Men who became partnered fathers then experienced large declines in waking (median: −26%) and evening (median: −34%) T, which were significantly greater than declines in single nonfathers (P < 0.001). Consistent with the hypothesis that child interaction suppresses T, fathers reporting 3 h or more of daily childcare had lower T at follow-up compared with fathers not involved in care (P < 0.05). Using longitudinal data, these findings show that T and reproductive strategy have bidirectional relationships in human males, with high T predicting subsequent mating success but then declining rapidly after men become fathers. Our findings suggest that T mediates tradeoffs between mating and parenting in humans, as seen in other species in which fathers care for young. They also highlight one likely explanation for previously observed health disparities between partnered fathers and single men.

Longitudinal evidence that fatherhood decreases testosterone in human males

The serum testosterone concentrations of 28 volunteers were investigated daily during abstinence periods after ejaculation for two phases. The authors found that the fluctuations of testosterone levels from the 2nd to 5th day of abstinence were minimal. On the 7th day of abstinence, however, a clear peak of serum testosterone appeared, reaching 145.7% of the baseline ( P < 0.01). No regular fluctuation was observed following continuous abstinence after the peak. Ejaculation is the precondition and beginning of the special periodic serum testosterone level variations, which would not occur without ejaculation. The results showed that ejaculation-caused variations were characterized by a peak on the 7th day of abstinence; and that the effective time of an ejaculation is 7 days minimum.

This current study examined the effect of a 3-week period of sexual abstinence on the neuroendocrine response to masturbation-induced orgasm…Orgasm increased blood pressure, heart rate, plasma catecholamines and prolactin. These effects were observed both before and after sexual abstinence. In contrast, although plasma testosterone was unaltered by orgasm, higher testosterone concentrations were observed following the period of abstinence. These data demonstrate that acute abstinence does not change the neuroendocrine response to orgasm but does produce elevated levels of testosterone in males.

Our meta-analysis showed that in men with an average T level at baseline below 12 nmol/l, T treatment moderately improved the number of nocturnal erections, sexual thoughts and motivation, number of successful intercourses, scores of erectile function and overall sexual satisfaction, whereas T had no effect on erectile function in eugonadal men compared to placebo. Heterogeneity was explored by grouping studies according to the characteristics of the study population. A cut-off value of 10 nmol/l for the mean T of the study population failed to predict the effect of treatment, whereas the presence of risk factors for vasculogenic erectile dysfunction (ED), comorbidities and shorter evaluation periods were associated with greater treatment effects in the studies performed in hypogonadal, but not in eugonadal, men. Meta-regression analysis showed that the effects of T on erectile function, but not libido, were inversely related to the mean baseline T concentration…The evidence for a beneficial effect of T treatment on erectile function should be tempered with the caveats that the effect tends to decline over time, is progressively smaller with increasing baseline T levels, and long-term safety data are not available.

Eisenegger et al’s The role of testosterone in social interaction; starting page 267, Neurobiological mechanisms underlying the role of testosterone in social status hierarchies (due to my own musings about the possible effects of masturbation went that it might be misinterpreted as reproductive success which reduces risk-taking or activity in general):

Maintaining a high status position requires an increased sensitivity for aversive events and impending social threats, particularly those that challenge the high social status of an individual. As we show below, testosterone appears to be able to influence such processes; in particular, it appears to confer high motivational drive, low fearfulness and high stress-resilience, either directly or via interactions with other hormones and neurotransmitter systems.

Fear & stress:

Among healthy young men, the blood oxygen level-dependent (BOLD) response in the amygdala to fearful and angry faces co-varies positively with individual differences in serum testosterone concentrations ([63,64], but see [65]). Exogenous testosterone has been shown to activate the amygdala in young women viewing angry facial expressions [66] (Figure 4). A mechanism underlying these observations might be that testosterone induces a functional decoupling between OFC and amygdala activity [67,68]…In humans, single acute doses of testosterone have been shown to reduce subconscious fear (Figure 5) and fear-potentiated startle [44,89].

…In face-to-face interactions, individuals are assumed to compete for status in fairly well-defined contests, each trying to outstress the other with verbal and facial cues, and the fact that low-ranked members show more stress symptoms than higher-ranked members during mutual interaction is a common feature of status hierarchies [40]. Stress probably also plays an important role in anonymous competition. Hence, stress resilience might enable an individual to cope with a challenge adaptively. Studies in animals have confirmed that testosterone downregulates the hypothalamic-pituitary-adrenal stress response [90]. It has also been shown to attenuate the sympathetically mediated stress response to aversive stimuli in humans [91].

During increasing dopamine depletion in this case, a range of subjective experiences appeared and disappeared consecutively. These experiences resembled negative symptoms, obsessive-compulsive symptoms, thought disorders, and anxiety and depressive symptoms and highlight the importance of the role of dopamine in major psychiatric disorders. In former studies, AMPT was found to lower mood, induce fatigue, decrease subjective alertness, and/or induce extrapyramidal symptoms in some healthy individuals (reviewed in reference 3). Since the subjective experiences due to acute dopamine depletion could be dramatic, we believe that subjects participating in dopamine-depletion studies should be well informed about possible temporarily-but intense-side effects.

Motivation & learning:

Reward-based reinforcement effects in animals have been observed within short time periods (30 min) after systemic administration of testosterone [79], suggesting that a testosterone surge following a status-relevant social stimulus might reinforces any behavior that led to that testosterone response in the first place. In humans, patients who are hypogonadal (testosterone levels too low) show apathy and lack of motivation [80], whereas testosterone administration in healthy subjects induces motivation to act [81] and upregulates activity in the ventral striatum [82]

The Past, Present, and Future of the Human Family, Tanner Lecture Sarah Blaffer Hrdy 2001

Only in the last few years has it become clear that elevated prolactin levels can be found in any allomother defending or nurturing immatures, not just in genetic parents. Prolactin levels in yearling scrub jays, for example, go up when they are carrying food back to nestlings. Among cooperatively breeding primates like marmosets,

close contact with infants stimulates release of prolactin in nonreproductives (among Callithrix jacchus: Roberts et al., in press) as well as leading to reductions in testosterone (among Callithrix kuhlii: Nunes et al. 2000). The longer the male carries the infant, or the more experienced the male is prior to caretaking, the stronger are these effects. The biggest surprise, though, was discovering that changes in hormonal levels during a woman’s pregnancy might play a role in priming nearby men. Prolactin levels in men living with pregnant women go up over the course of their pregnancy, as do cortisol levels and to some extent estradiol. The most significant effect was the 30% drop in testosterone in men right after birth. Declining testosterone might increase paternal behaviors simply by reducing male involvement in other behaviors that divert them from nurturing-like competing with other males. The more responsive to infants men are, the more likely it is that their testosterone will continue to drop (Storey et al. 2000; Wynne-Edwards and Reburn 2000).

Roberts, R. Lucille, Kosunique T. Jenkins, Theodore Lawler, Jr., Frederick H. Wagner, Janet L. Norcross, Deborah E. Bernhards, and John D. Newman. In press. Prolactin Levels Are Increased after Infant Retrieval and Carrying in Parentally Inexperienced Common Marmosets. [email protected]

Nunes, Scott, Jeffrey Fite, and Jeffrey French. 2000. Variation in Steroid Hormones Associated with Infant Care Behaviour and Experience in Male Marmosets (Callithrix kuhlii). Animal Behaviour 60, no. 6: 857-65.

Storey, Anne E., Carolyn J. Walsh, Roma L. Quinton, and Katherine E. Wynne-Edwards. 2000. Hormonal Correlates of Paternal Responsiveness in New and Expectant Fathers. Evolution and Human Behavior 21, no. 2: 79-95

Wynne-Edwards, Katherine, and Catharine J. Reburn. 2000. Behavioral Endocrinology of Mammalian Fatherhood. Trends in Ecology and Evolution 15, no. 11: 464-68

Prolactin and dopamine are antagonists of one another. In fact, dopamine was first known as Prolactin Inhibiting Factor. Prolactin suppresses testosterone production, and produces the refractory period that most men experience after orgasm. This is why dopaminergic drugs shorten or eliminate the refractory period. Insofar as many people regard dopaminergic drugs as nootropics (e.g. amphetamines, caffiene, etc), keeping prolactin levels low by not having an orgasm could have a nootropic effect.

Little is known about what happens in the brain during sex. In 2005, Dr. Gert Holstege at the University of Groningen in the Netherlands used positron emission tomography to scan the brains of men and women during orgasms. He discovered, among other changes, a sharp decrease in activity in the amygdala, the brain region involved in processing fearful stimuli. Aside from causing pleasure, sex clearly lowers fear and anxiety. The anthropologist Helen Fisher, of Rutgers, used functional magnetic resonance imaging to look more broadly at the neural circuitry of romantic love. She showed a group of young men and women who reported being passionately in love a photo of their beloved or a neutral person. Subjects showed marked activation in the brain’s dopamine reward circuit only in response to the beloved, similar to the brain’s response to other rewards like money and food. Could it be that some patients have particularly strong rebound activity in the amygdala after orgasm that makes them feel bad? The research literature is virtually silent on sex-induced depression, but a Google search revealed several Web sites and chat rooms for something called postcoital blues. Who knew? There, I read many accounts nearly identical to those of my patients, with reports of various remedies for the malady.

…A clue to a possible treatment is that Prozac and its cousins, selective serotonin reuptake inhibitors, commonly interfere with sexual functioning to some degree. Serotonin is good for your mood, but too much of it in your brain and spinal cord is decidedly bad for sex. I thought that if I could somehow modulate my patients’ sexual response, make it less intense, it might blunt the negative emotional state afterward. In other words, I would exploit the usually undesirable side effects of the SSRI’s for possible therapeutic effect. As anyone who has taken one of these drugs for depression can tell you, it may take a few weeks to feel better, but side effects, like sexual dysfunction, are often immediate. For my patients, that turned out to be an advantage. After just two weeks on an SSRI, both said that while sex was less intensely pleasurable, no emotional crash followed.

The mechanism of action is not exactly understood[16] but it is assumed that it has dopaminergic effects resulting in changes of prolactin secretion. At low doses, such as might have been used in previous centuries for suppression of sexual desire, it inhibits activation of dopamine 2 receptor by competitive binding, causing a slight increase in release of prolactin. In higher concentrations, as in modern extracts, the binding activity is sufficient to reduce the release of prolactin. A study has found that treatment of 20 healthy men with higher doses of Vitex agnus-castus was associated with a slight reduction of prolactin levels, whereas lower doses caused a slight increase as compared to doses of placebo.[17]

Coolidge effect: novel partner/stimulus coaxes out superhuman sexual performance

The present study examined whether women’s testosterone levels are influenced by being with a sexual and romantic partner after a period of sexual abstinence. Women in long distance relationships (n=15) provided five saliva samples: at least 1 week before seeing their partner (and at least 2 weeks since their last visit), the day before seeing their partner, when they were with their partner but prior to engaging in sexual activity, the day after their first sexual activity, and 3 days after they were separated from their partners. Salivary testosterone was lowest when participants had been away from their partners for at least 2 weeks and highest the day before they were to see their partners and the day after sexual activity. Results from this study indicated that women’s testosterone increased both the day before they were with their partners and they day after they first engaged in sexual activity. However, something about initially reuniting with their partners returned their testosterone to baseline levels, which may be an effect of being in the same location as a partner, or just a state fluctuation due to nervousness or other psychological state.

The effects of partner togetherness on salivary testosterone in women in long distance relationships, Hamilton & Meston 2010

The object of the study was to assess the lability of testosterone levels in plasma of normal human males over a long period of time and to search for periodicities in changing levels. Blood samples obtained from 20 healthy young men every second day for 2 months were assayed for total testosterone concentration by radioligand saturation analysis with late-pregnancy plasma. The flucturations of plasma testosterone levels over the total time span were substantial for most individuals; the coefficients of variation ranged from 14 to 42% (median 21%). The presence of periodic functions in these fluctuations was tested by 4 different, relatively independent methods. Close agreement among at least 3 analytic methods was found for 12 out of the 20 subjects. These 12 subjects had cycles of plasma testosterone levels with periods ranging between 8-30 days, with a cluster of periods around 20-22 days. The majority of such cycles were significant at least at the 5% level. The mean amplitudes of these cycles ranged from 9 to 28% of the subjects’ mean testosterone levels (average 17%).

A cycle of plasma testosterone in the human male, Doering et al 1975; testosterone cycles quite a bit

The levels of pregnenolone, dehydroepiandrosterone (DHA), androstenedione, testosterone, dihydrotestosterone (DHT), oestrone, oestradiol, cortisol and luteinizing hormone (LH) were measured in the peripheral plasma of a group of young, apparently healthy males before and after masturbation. The same steroids were also determined in a control study, in which the psychological anticipation of masturbation was encouraged, but the physical act was not carried out. The plasma levels of all steroids were significantly increased after masturbation, whereas steroid levels remained unchanged in the control study. The most marked changes after masturbation were observed in pregnenolone and DHA levels. No alterations were observed in the plasma levels of LH.

Endocrine effects of masturbation in men, Purvis et al 1976

Data regarding the neuroendocrine response pattern to sexual arousal and orgasm in man are inconsistent. In this study, ten healthy male volunteers were continuously monitored for their cardiovascular and neuroendocrine response to sexual arousal and orgasm. Blood was continuously drawn before, during and after masturbation-induced orgasm and analyzed for plasma concentrations of adrenaline, noradrenaline, cortisol, luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin, growth hormone (GH), beta-endorphin and testosterone. Orgasm induced transient increases in heart rate, blood pressure and noradrenaline plasma levels. Prolactin plasma levels increased during orgasm and remained elevated 30 min after orgasm. In contrast, none of the other endocrine variables were significantly affected by sexual arousal and orgasm.

Neuroendocrine and cardiovascular response to sexual arousal and orgasm in men, Krüger et al 1998

Twenty males participated in a 2-month study examining the relationship between 8 a.m. plasma testosterone levels and orgasmic frequency. Within subjects, higher levels of testosterone are associated with periods of sexual activity. Over subjects, however, the direction of the relationship is reversed. Mean testosterone levels were higher for sexually less active individuals.

Actually, Meth may well raise dopamine about 1000 times more than sex. That is probably the main reason only 2% of people that get addicted to Meth ever get off it long term. If you want to test your willpower against meth, you are going to lose. Cocaine increases dopamine by about 350% over baseline, sex increases dopamine 100 % over baseline and just eating food increases dopamine 50% over baseline. So food gets you half as far as sex as far as dopamine is concerned. I once read music can increase dopamine almost as much as cocaine. Nicotine appears to increase dopamine more than sex.

http://www.longecity.org/forum/topic/51668-masturbation-and-cognition/page__st__60__p__479691#entry479691

• https://secure.wikimedia.org/wikipedia/en/wiki/Dopamine#Motivation_and_pleasure
• http://www.reuniting.info/science/articles/acute_dopamine_depletion_causes_psychological_distress
• http://scienceblogs.com/cortex/2008/02/dopamine_and_orgasm.php
• http://www.psychologytoday.com/blog/cupids-poisoned-arrow/200910/unexpected-lessons-porn-users
• http://www.humantruth.info/masturbation.html

Anecdotes:

• http://www.longecity.org/forum/topic/47369-semen-retention-as-a-nootropic/
• http://www.longecity.org/forum/topic/51668-masturbation-and-cognition/
• http://themodernsavage.com/2009/02/04/effects-of-male-masturbation-on-attracting-women/
• http://nymag.com/news/features/70976/
• http://www.psychologytoday.com/blog/cupids-poisoned-arrow/201107/porn-induced-sexual-dysfunction-is-growing-problem (also mentions a survey)
• http://www.slate.com/articles/arts/culturebox/features/2013/daily_rituals/balzac_and_sex_how_the_french_novelist_used_masturbation_to_fuel_his_writing.html

# Cryptonomicon

The relevant quotes:

He gets to the point, conceptually, where his grandfather was when he commenced breaking the Arethusa messages. That is, he has a theory in mind now of how Arethusa worked. If he doesn’t know the exact algorithm, he knows what family of algorithms it belongs to, and that gives him a search space with many fewer dimensions than he had before. Certainly few enough for a modern computer to explore. He goes on a forty-eight-hour hacking binge. The nerve damage in his wrists has mounted to the point where he practically has sparks shooting out of his fingertips. His doctor told him never again to work on these nonergonomic keyboards. His eyes start to go out on him too, and he has to invert the screen colors and work with white letters on a black background, gradually increasing the size of the letters as he loses the ability to focus. But at last he gets something that he thinks is going to work, and he fires it up and sets it to running on the Arethusa intercepts, which live inside the computer’s memory but have never yet been displayed upon its screen. He falls asleep. When he wakes up, the computer is informing him that he’s got a probable break into one of the messages. Actually, three of them, all intercepted on 4 April 1945 and hence all encrypted using the same keystream.

He could very easily take care of the Hunk of Burning Love problem now that he has privacy, but astonishes himself by electing not to. This may be perverse; he’s not sure. The last month and a half of total celibacy, relieved only by nocturnal emissions at roughly two-week intervals, has definitely got him in a mental space he has never been to before, or come near, or even heard about. When he was in jail he had to develop a fierce mental discipline in order not to be distracted by thoughts of sex. He got alarmingly good at it after a while. It’s a highly unnatural approach to the mind/body problem, pretty much the antithesis of every sixties and seventies-tinged philosophy that he ever imbibed from his Baby Boomer elders. It is the kind of thing he associates with scary hardasses: Spartans, Victorians, and mid-twentieth-century American military heroes. It has turned Randy into something of a hardass in his approach to hacking, and meanwhile, he suspects, it has got him into a much more intense and passionate head space than he’s ever known when it comes to matters of the heart. He won’t really know that until he comes face to face with Amy, which looks like it’s going to be a while, since he’s just been kicked out of the country where she lives and works. Just as an experiment, he decides he’s going to keep his hands off of himself for now. If it makes him a little tense and volatile compared to his pathologically mellow West Coast self, then so be it. One nice thing about being in Asia is that tense, volatile people blend right in. It’s not like anyone ever died from being horny.

Results.  A wide range of better psychological and physiological health indices are associated specifically with penile-vaginal intercourse. Other sexual activities have weaker, no, or (in the cases of masturbation and anal intercourse) inverse associations with health indices. Condom use appears to impair some benefits of penile-vaginal intercourse. Only a few of the research designs allow for causal inferences.

Masturbation is Related to Psychopathology and Prostate Dysfunction: Comment on Quinsey (2012), Costa 2012; obviously these correlations all have massive selection & correlation≠causation problems, or is it a surprise that poor relationships might cause masturbation⸮

It is difficult to reconcile the view that masturbation improves mood with the findings in both sexes that greater masturbation frequency is associated with more depressive symptoms (Cyranowski et al., 2004; Frohlich & Meston, 2002; Husted & Edwards, 1976), less happiness (Das, 2007), and several other indicators of poorer physical and mental health, which include anxious attachment (Costa & Brody, 2011), immature psychological defense mechanisms, greater blood pressure reactivity to stress, and disatisfaction with one’s mental health and life in general (for a review, see Brody, 2010). It is equally difficult to see how masturbation develops sexual interests, when greater masturbation frequency is so often associated with impaired sexual function in men (Brody & Costa, 2009; Das, Parish, & Laumann, 2009; Gerressu, Mercer, Graham, Wellings, & Johnson, 2008; Lau, Wang, Cheng, & Yang, 2005; Nutter & Condron, 1985) and women (Brody & Costa, 2009; Das et al., 2009; Gerressu et al., 2008; Lau, Cheng, Wang, & Yang, 2006; Shaeer, Shaeer, & Shaeer, 2012; Weiss & Brody, 2009). Greater masturbation frequency is also associated with more dissatisfaction with relationships and less love for partners (Brody, 2010; Brody & Costa, 2009). In contrast, PVI [penis-vaginal intercourse] is very consistently related to better health (Brody, 2010; Brody & Costa, 2009; Brody & Weiss, 2011; Costa & Brody, 2011, 2012), better sexual function (Brody & Costa, 2009; Brody & Weiss, 2011; Nutter & Condron, 1983, 1985; Weiss & Brody, 2009), and better intimate relationship quality (Brody, 2010; Brody & Costa, 2009; Brody & Weiss, 2011).

• Brody, S., & Costa, R. M. (2009). Satisfaction (sexual, life, relationship, and mental health) is associated directly with penile-vaginal intercourse but inversely with other sexual behavior frequencies. Journal of Sexual Medicine, 6, 1947-1954.
• Brody, S., & Weiss, P. (2011). Simultaneous penile-vaginal intercourse orgasm is associated with satisfaction (sexual, life, partnership, and mental health). Journal of Sexual Medicine, 8, 734-741
• Costa, R. M., & Brody, S. (2011). Anxious and avoidant attachment, vibrator use, anal sex, and impaired vaginal orgasm. Journal of Sexual Medicine, 8, 2493-2500.
• Costa, R. M., & Brody, S. (2012). Greater resting heart rate variability is associated with orgasms through penile-vaginal intercourse, but not with orgasms from other sources. Journal of Sexual Medicine, 9, 188-197.
• Cyranowski, J. M., Bromberger, J., Youk, A., Matthews, K., Kravitz, H. M., & Powell, L. H. (2004). Lifetime depression history and sexual function in women at midlife. Archives of Sexual Behavior, 33, 539-548.
• Das, A. (2007). Masturbation in the United States. Journal of Sex and Marital Therapy, 33, 301-317.
• Das, A., Parish, W. L., & Laumann, E. O. (2009). Masturbation in urban China. Archives of Sexual Behavior, 38, 108-120
• Frohlich, P., & Meston, C. (2002). Sexual functioning and self-reported depressive symptoms among college women. Journal of Sex Research, 39, 321-325
• Gerressu, M., Mercer, C. H., Graham, C. A., Wellings, K., & Johnson, A. M. (2008). Prevalence of masturbation and associated factors in a British national probability survey. Archives of Sexual Behavior, 37, 266-278
• Husted, J. R., & Edwards, A. E. (1976). Personality correlates of male sexual arousal and behavior. Archives of Sexual Behavior, 5, 149-156.
• Lau, J. T., Cheng, Y., Wang, Q., & Yang, X. (2006). Prevalence and correlates of sexual dysfunction among young adult married women in rural China: A population-based study. International Journal of Impotence Research, 18, 89-97.
• Lau, J. T., Wang, Q., Cheng, Y., & Yang, Y. (2005). Prevalence and risk factors of sexual dysfunction among younger married men in a rural area in China. Urology, 66, 616-622.
• Nutter, D. E., & Condron, M. K. (1983). Sexual fantasy and activity patterns of females with inhibited sexual desire versus normal controls. Journal of Sex and Marital Therapy, 9, 276-282.
• Nutter, D. E., & Condron, M. K. (1985). Sexual fantasy and activity patterns of males with inhibited sexual desire and males with erectile dysfunction versus normal controls. Journal of Sex and Marital Therapy, 11, 91-98.
• Shaeer, O., Shaeer, K., & Shaeer, E. (2012). The Global Online Sexuality Survey (GOSS): Female sexual dysfunction among internet users in the reproductive age group in the Middle East. Journal of Sexual Medicine, 9, 411-424.
• Weiss, P., & Brody, S. (2009). Female sexual arousal disorder with and without a distress criterion: Prevalence and correlates in a representative Czech sample. Journal of Sexual Medicine, 6, 3385-3394

one serious question: given that masturbation is universal throughout the human world and human history, and is as universal as homosexuality among animals (see Wikipedia for the fascinating gamut of animal sexual activities), why does masturbation still exist? If it’s really true that masturbation has recognizable different characteristics in terms of testosterone or prolactin secretion or satisfaction etc, then the difference between masturbation and more reproductively-fit sex can be acted upon by bodily systems and so can be acted upon by evolution and so can eventually be eliminated. Evolution has resulted in fantastically subtle mechanisms and choices in other areas, and there’s no lack of species or time-scale for masturbation to be eliminated in animals; so why does it exist?