Sex, Sleep and the Law: When Nocturnal Genitals Pose a Moral Dilemma

It may seem to you that, much like their barnyard animal namesake, men’s reproductive organs the world over participate in a mindless synchrony of stiffened salutes to the rising sun. In fact, however, such "morning wood" is an autonomic leftover from a series of nocturnal penile tumescence (NPT) episodes that occur like clockwork during the night for all healthy human males—most frequently in the dream-filled rapid eye movement (REM) periods of sleep from which we’re so often rudely awakened in the A.M. by buzzers, mothers, or others.

For those with penises, you may be surprised to learn how frequently your member stands up while the rest of your body is rendered catatonic by the muscular paralysis that keeps you from acting out your dreams. (And thank goodness for that. Carlos Schenck and his colleagues [pdf] from the University of Minnesota Regional Sleep Disorders Center describe the case of a 19-year-old with sleep-related dissociative disorder crawling around his house on all fours, growling, and chewing on a piece of bacon—he was ‘dreaming’ of being a jungle cat and pouncing on a slab of raw meat held by a female zookeeper.) Scientists have determined that the average 13- to 79-year-old penis is erect for about 90 minutes each night, or 20 percent of overall sleep time. With your brain cycling between the four sleep stages, your "sleep-related erections" appear at 85-minute intervals lasting, on average, 25 minutes. (It’s true; they used a stopwatch.) I didn’t come upon any evolutionary theories or a proposed "adaptive function" of NPT, but we do know that it’s not related to daytime sexual activity, it declines (no pun intended) with age, and it’s correlated positively with testosterone levels. Females similarly exhibit vaginal lubrication during their REM-sleep, presumably with many dreaming of erect penises.

Now, you may not think that such tedious biological details would be fodder for a moral quandary, but you underestimate our species’ massive confusion when it comes to understanding how its coveted free will articulates with its genitalia. Consider the case of a young Frenchman whose sleep-related erection was interpreted by another man as a sign of sexual interest but, swore the former, was nothing of the kind. As described by a group of investigators at the Annual Meeting of the French Sleep Research Society in 2001, the 24-year-old heterosexual male awoke to his horror with painful anal lesions. Although he had no conscious recollection of any such incident occurring, this led him to deduce that he must have been raped during the night. "The legal medical examination indeed reported on visibly recent tears of the anal margin," confirmed the researchers.

Then comes the sobering whodunit. What was especially disquieting is that the man’s boss had slept over the night before. The two had earlier been lounging in the pool and roasting together in the sauna. There was absolutely no evidence of date rape drugs, but alcohol, as it so often does in the south of France, flowed with relatively gay abandon that evening, and so the straight employee, being a gentleman, had invited his employer to sleep it off on his sofa while he retired to the mezzanine. Apparently, however, it was the employee that slept particularly hard that night, not the inebriated boss. The older man admitted readily that of course they’d had sex overnight, and he could only assume that his colleague’s erection, combined with the fact that the other didn’t resist as he mounted him, suggested that he was a consensual partner. (You thought you were a deep sleeper—imagine the somnambulistic fortitude required to snooze through your first anal penetration.) While the courts tried to sort it all out, the alleged rapist was imprisoned for two years, until finally a judge decided that both men were more or less right and the accused should be set free.

This is but one of many curious examples of sex and law intertwining. In recent years, the related phenomenon of sexsomnia ("sleep sex") has witnessed periodic public interest through a spate of high-profile cases, stories that have in turn motivated intriguing academic research on this little-known subject. Even Alfred Kinsey, the grand archivist of carnal facts, while spending a considerable deal of time on the subject of "wet dreams" and nocturnal orgasms in both sexes, didn’t mention how some people act out sexually during their sleep.

Unlike the aforementioned case of the sleeping employee being the passive, immobilized recipient in unwanted intercourse, it’s the sleeper that instigates the trouble in bouts of sexsomnia. Although researchers don’t yet have an exact figure on the frequency of this parasomnia, most specialists believe that it’s probably fairly common. Nearly all people who exhibit recurrent sexual acts while sleeping have a history of sleepwalking. In fact, many experts believe that sexsomnia is simply a variant of sleepwalking, which affects 1 to 2% of adults, and this is how it’s presently classified in the main diagnostic manual, the International Classification of Sleep Disorders, Revised. Most people do not seek out clinical treatment due to either their ignorance of the condition or embarrassment, and oftentimes their sexual ‘automatisms’ are innocuous enough—such as fugue-state masturbation, weak pelvic thrusts or steamy pillow talk. (More on the concept of automatism in a moment.)

In a 2007 issue of Brain Research Reviews, however, psychobiologist Monica Andersen and her co-authors [pdf] investigated all case studies that had, at that point, been published in the literature, and they attempted to piece together some common denominators underlying sexsomnia. They found that the most common precipitating factors of sleepsex are sleep deprivation, stress, alcohol or drug consumption, excessive fatigue, and physical overactivity in the evening. Being male and under the age of 35 is also a major factor; furthermore, when women do lapse into this altered nocturnal state, their actions tend to be comparatively innocent, moaning and masturbating rather than, like male sexsomniacs, fondling and grinding whatever is unfortunate enough to be in the vicinity of their bed that night.

Read the rest on Scientific American.