It’s an amusing, albeit often highly inconvenient, phenomenon that half of the world’s population has to deal with on a regular basis. So what’s the science story behind that morning glory? Let’s find out. Morning glories, or nocturnal penile tumescence (NPT) as they are correctly called, are spontaneous erections that occur during sleep or while waking up. All blokes without erectile dysfunction are graced with them and they normally occur around three to five times during sleep. NPT actually starts in utero , or in the womb (seriously), and continues throughout life. If it’s any consolation, men aren’t completely alone—women also get clitoral erections and vaginal engorgement during sleep, and various non-human mammals also get NPT, according to iflscience.com While a few different theories have been proposed over the years to explain NPT, what causes it still remains uncertain. NPT, just like clitoral erections, is associated with REM (rapid eye movement) sl
