"Winged Cupid, rash and hardy, who by his evil manners, contemning all public justice and law, armed with fire and arrows, running up and down in the nights from house to house, and corrupting lawful marriages of every person, doth nothing but evil." —Lucius Apuleius, The Tale of Cupid and Psyche (late second century A.D.)

I didn’t fear Cupid when I was a child, but little did I know he was a malevolent demon. By the time I first came to know him in the 1970s, Cupid’s dark side was unrecognizable, having long since been painted over with baby fat and giggles by Hallmark and other great cultural bowdlerizers. This dramatic transformation of evil Cupid into a jubilant cherub, pink as a piglet’s bottom and sweet as a lamb, who spies you each approaching Valentine’s Day with twinkling eyes from the greeting-card display of your local pharmacy, who twirls with his arrow drawn ever so gently in the form of a paper mobile pinned to the ceilings of third-grade classrooms, bears faint resemblance to his original manifestation. He still strikes me as a bit cheeky, but the real Cupid was a genuine sociopath.

It was the Roman writer Lucius Apuleius who brought Cupid to life in his ancient book of fables, The Golden Ass. Apuleius’s Cupid was no mischievous toddler with hummingbird wings but an impulsive god who rejoiced in causing sexual havoc for all earthly creatures. Even the fearless Apollo refers to Cupid as “serpent dire and fierce”:

Who flies with wings above in starry skies,

And doth subdue each thing with fiery flight.

The Gods themselves and powers that seem so wise With mighty love be subject to his might.

The rivers black and deadly floods of pain

And darkness eke as thrall to him remain.

Apuleius’s story reads like a second-century black comedy. Cupid’s mother, Venus, is jealous of a mortal girl named Psyche whose beauty surpasses even her own. Seeking vengeance, Venus recruits her son, this bringer of misplaced desire, to shoot one of his fearsome poisoned arrows into the young maiden so that she’ll forever covet the first reproachful thing she sets eyes upon, thereby punishing Psyche’s “disobedient beauty” with a shameful attraction. “I pray thee without delay,” says Venus pleadingly to her son Cupid, “that she may fall in love with the most miserable creature living, the most poor, the most crooked, and the most vile, that there may be none found in all the world of like wretchedness.”

Cupid breaks into Psyche’s house one night and fully intends to do just this for his mother, but he becomes so smitten with Psyche that he accidentally pricks himself with his own poisoned arrow while watching her sleep. This forever binds the two and leads to Psyche’s entry by marriage into the Roman pantheon—and, to put it mildly, a rather tense relationship with her new mother-in-law.

Love may have saved him in the end, but Apuleius’s Cupid wasn’t so much a romantic matchmaker as a devil subjecting hapless people to a toxic lust, one that blinded them with hypersexual urges. This allegory of a capricious god who pierces mortal hearts only to burden them with some scandalous attraction out of sheer boredom or as favors to other gods is reminiscent of nature’s cold mindlessness when it comes to human sexuality. Individuals with the most deviant desires have similarly found themselves at the whim of a terrible randomness. To learn more about the science of "erotic outliers," read my new book Perv. [EXCERPT].