Since 1886 when Robert Louis Stevenson published The Strange Case of Dr. Jekyll and Mr. Hyde, the idea of a good self and a bad self, divisible and distinct, coexisting within the psyche has taken hold with such force that despite everything we've learned about human psychology it continues to hold currency in the cultural imagination, all the more so since the dual character of Jekyll and Hyde undergoes endless adaptation and interpretation, having appeared in well over a hundred cinematic versions alone, not including parodies, spin-offs, or television, stage, and radio adaptations. I start with Dr. Jekyll and Mr. Hyde because it's the ur-text when it comes to stories about doppelgangers and split personalities.
It's also worth noting, as Nabokov did in his essay on the novella, that Jekyll and Hyde are not the good and bad halves of the personality, although this paradigm has become the norm in cultural representations of the story. Rather, Jekyll "is a composite being, a mixture of good and bad, a preparation consisting of ninety-nine percent solution of Jekyllite and one percent of Hyde." Thus, the way in which we use the names of Jekyll and Hyde is usually and fundamentally wrong. Hyde is all bad, but Jekyll is far from all good because he is human and there is his ultimate folly. He doesn't succeed in separating the good from the bad; he succeeds in separating the bad from the good, granting autonomy to the bad, while the good remains trapped in the complexities of his identity as Jekyll.
Nabokov makes another astute observation about the novella, echoing the critic Stephen Gwynn: women are almost wholly absent from the story, mere furniture in the street scenes, objects to be walloped by Hyde, frightened creatures that weep and faint under the ghastly influence of the bogey's presence. There isn't a line of dialogue spoken by a female character. The maidservant who observes Hyde's brutal murder of Danvers is quoted only indirectly. Stevenson's "monkish" version of London is thus curiously free of perhaps the most obvious duality of Victorian society: gender. The characters are all bachelors, well-to-do and fond of a glass of fine wine, lawyers, doctors, and scientists.
Film adaptations typically follow the example set by theatrical adaptations with the addition of two female characters: a beautiful, aristocratic, and virginal fiancee for Jekyll and a victimized, terror-stricken prostitute or cabaret dancer for Hyde. Thus, the queasily vague and sadistically flavored forbidden pleasures of the novella's Hyde become explicitly sexual (and heterosexual, though were I to write an adaptation of the story, given the almost exclusively male milieu, I would be inclined towards making Jekyll's "undignified" and embarrassing proclivities homosexual). In what I consider the best version, Rouben Mamoulian's 1931 adaptation starring the brilliant Fredric March in perhaps his best performance, the pleasures Hyde is unleashed to pursue are very explicitly sexual. His fiancee's father continuously obstructs his marriage and the overt implication is that Jekyll's bad side is driven to violence by his sexual frustration. Whereas Hyde's victims in the novel are attacked out of pique and irritation, Hyde's victims in the film are rape and attempted rape victims and a man who stands in the way of his sexual conquest of Jekyll's fiancee. Implicit in these choices is an underlying assumption that the bad in man is fortified by a lack of "natural" outlets that men need to quiet the violence and sexual desire within.
A similar assumption runs through Albert Lewin's idiosyncratic 1945 adaptation of The Picture of Dorian Gray. Though Dorian's proclivities are allowed to remain somewhat shrouded in mystery, sexuality is at the core of his indulgences and women are again the victims of his selfishly pursued pleasures. Again, there are two female figures: the upper-class, virginal fiancee and the lower-class victimized pub singer. Though Dorian may have more refined and sophisticated tastes than Hyde, in both films a mystical transformation, reflected in a splitting both physical and psychological, is the catalyst for the emergence of repressed sexual desire, desire that becomes violent when an attempt is made to control it.
A similar duality - the bestial, sexual self and the moral, responsible, repressed self - is found again and again in films in which men are tormented with a split personality. In M, Fritz Lang's 1931 masterpiece, the murderer and implied pedophile Hans Beckert, whose crimes are so heinous that he is put on trial by the criminal underworld, protests desperately that no one can understand him, no one can understand why he is helplessly driven to commit atrocities that he knows to be evil. He leads a double life, his transition to the evil side of his personality signaled by his whistling "In the Hall of the Mountain King." Such a dichotomy even finds echoes in Jean Cocteau's eerie 1946 adaptation of Beauty and the Beast, in which the tormented beast fights the bestial instincts that threaten to overtake the sensitive, suffering human nature underneath. That bestiality is somewhat tamed by Beauty's positive attentions, by her pity, by the simple gesture of touching him without fear, but fanned by the sight of her sleeping, helpless body. This sexual duality is given perhaps its ripest treatment in Philip Kaufman's 2000 film, Quills, in which the Abbé falls under the influence of the Marquis de Sade, who ultimately succeeds in dismantling the humane, rational, Christian, and moral man to reveal the sexually aroused, manic, and dangerous man - the man not restrained by either compassion or faith - lurking underneath. The unhinged madman, the man who compulsively seeks to live out his sexual fantasies, whether physically or on paper, is what remains.
If rampant sexual desire, exploding forth as violent deviance when it lacks an outlet, is often at the root of the split personality, so is skepticism. As Freud's theories became more deeply ingrained and more frequently questioned, horror films began to dwell increasingly on a new, modernized danger: unbelief. This is not the lack of Christian faith instilled by older vampire stories and early horror films, such as Carl Theodor Dreyer's 1932 cult masterpiece, Vampyr. Rather, the modern danger of unbelief is a denial of a supernatural reality that borrows heavily from both pagan and monotheistic symbolism, imagery, and lore, but that is secularized in that it lacks any firm theological foundation. In An American Werewolf in London, John Landis's landmark 1981 film, skepticism and a modern resistance to belief in the supernatural are the underlying cause of David Kessler's wandering into the path of a werewolf, to become one himself. His inability to grant credence to the stuff of nightmares, to give in to fear, proves his doom (and the death of more than a few others). In other words, his denial of his own irrationality proves his doom; the irrational overcomes the rational, just as the lustful Hyde takes over the sexually responsible Jekyll, just as the Abbé sheds his values and Christian faith and succumbs to an embrace of his most forbidden sexual desires.
What happens when it's a woman afflicted with a split personality, a monster lurking beneath the surface? In Val Lewton's Cat People, released in 1942, sexuality is at the core of monstrous transformation, but the mechanics of that transformation are in stark contrast to Dr. Jekyll's or Dorian Gray's. Irena believes herself to be descended from a Serbian race of "cat people." These people transform into panthers when sexually aroused and strike violently at whoever lies within their reach. Significantly, the only cat people encountered in the film are women. The difference here is that Irena holds little to no control. She has not experimented with some mystical scientific compound or made foolhardy vows to ancient gods. Instead, like the Beast, she is cursed by her heritage and loathes the violence within her. However, in contrast to the Beast, sexual arousal, whether born of love, lust, or jealousy, is always the catalyst for violence; whereas a line is drawn between the animalistic lust of the Beast and the pure, untainted love of the man within, for Irena, there is no possibility of any form of sexuality that doesn't render her a monster. For her, it is not a battle between a sexuality sanctioned by love and a sexuality driven by crude instinct; rather, her monstrosity lies within the fact that she is a sexual being, and it doesn't matter what emotion lies behind it.
In Brian De Palma's classic 1976 horror film, Carrie, the conflict is a bit more complicated. Carrie's telekinetic powers are awakened with the coming of sexual maturity (it's worth noting that all of the male characters I have listed above are older and already well within the aegis of sexual initiation). In this case, it is humiliation linked to her sexuality that releases her monstrosity, rather than sexuality itself, whether the cruel taunting of her evangelistic mother, the shrieking hilarity of the other girls in the locker room, hurling tampons at her, or the realization that a boy's seeming interest is not rooted in desire but in mockery. Carrie's murderous power is fueled by the denial of her sexuality by other people, by her inability to be safely sexual. Carrie's monstrosity is a reaction, not a chosen action, though it does carry a subversive power that defies, to an extent at least, the narrow strictures of American suburban life.
Based on Henry James's novella, The Aspern Papers, Martin Gabel's odd 1947 Gothic thriller, The Lost Moment, hints at a supernatural explanation for Miss Tina's split personality, but ultimately settles on psychosis driven by sexual repression. Tina's great-aunt was the lover of a brilliant and mysteriously disappeared poet and when Tina wears the ring he gave her and reads his letters, she transforms herself into a ghostly re-imagining of her aunt. A priest cautions the young publisher who has come in pursuit of the letters that a cure for Tina's madness lies in an actual, rather than an imagined, love affair. In other words, Tina's alternate personality is awakened because she has no lover of her own. But because Tina is a woman, she cannot, like Jekyll or Dorian Gray, pursue a relationship of her own. She is helpless, in thrall to her aunt's long-dead lover, simply because no flesh-and-blood lover has presented himself. There is no hubris, no selfishness, at the core of Tina's alternate personality - just loneliness. The evil part of her is essentially a tumor that will be cut away with the loss of her virginity.
Then there's Rhoda, eight years old, the cute little blonde tyke of Mervyn LeRoy's 1956 classic, The Bad Seed. The role of sexuality in this film is less overt, though still important. Rhoda's adoring mother discovers that she herself was adopted and that her own mother, Rhoda's grandmother, was a bloodthirsty serial killer. This proves the key to understanding Rhoda's personality. Outwardly sweet, smiling, and neat, attentive to her schoolwork and music lessons, Rhoda exhibits a disturbing lack of empathy, avarice, and the occasional shocking outburst. Though her mother initially wants to impute her daughter's cold selfishness and total lack of compassion to the trauma of seeing a little boy's corpse, the evidence stacks up and she is forced to confront the reality that her beloved daughter is a monster. In this film, evil is genetic, but it's significant that this particular evil is so specifically female. If Jekyll is, when himself, 99% Jekyll and 1% Hyde, then Rhoda is 99% evil and only 1% good. Rhoda's good half is the saccharine crust that covers the murdering, greedy hellion within; she wants to be perceived as perfect, rather than actually be so.
One striking thing to note about these female characters is the role that birthright plays in monstrosity. Whether there is an explicit genetic component - descent from "cat people" or a raging murderess - or a twisted family relationship - an abusive, sadistic mother or an obsessive quest to take the place of an ancestor - inheritance plays a distinctive role for these women that it does not for men. While men are individuals endowed with free will and the ability to destroy or redeem themselves, women are usually constricted not only by the restraints placed on women by society as a whole, but by some sort of tainted or unwholesome inheritance that corrupts them. While men hurl towards their destruction or painfully excise the evil and madness from their souls, whether to be absolved in death or life, women are either driven to their end by a monstrosity not of their own choosing or purpose or redeemed by someone else, inevitably a man. The fatal flaw in the male character destroys him when he acts upon it; the fatal flaw in the female character destroys her when she is acted upon.
There is a stark difference between male sexuality and female sexuality and the roles they play in the interaction of the two halves of a split personality. Male characters are permitted to be sexual beings - their sexually dangerous exploits are the result of a lack of healthy intercourse and the solution to their split personality is often posited as marriage to a (virginal) character. The stark exception is Hans Beckert whose sexual predilection for children renders him absolutely irredeemable. Attitudes towards female sexuality, on the other hand, have evolved significantly. Whereas in earlier films, women's sexual arousal was in and of itself dangerous, even within the context of marriage, slowly acceptance grew to allowing women a measure of sexual need, though only in the context of a love relationship, ideally culminating in marriage, that stresses female subjugation to men as sexual actors. With the feminist movement came a consciousness and greater acceptance of women as sexual beings, but female characters were still held between the poles of being loved, and thus able to express sexuality in relation to a man, and being unloved, and thus unable to even be sexual.
That being said, there is such a thing as a feminist horror film. Mitchell Lichtenstein's 2007 comedy-horror film, Teeth, is about a young woman, Dawn, who discovers that she has a vagina dentata. When I first heard about this film, and especially since it's directed by a man, I assumed that it must be intensely misogynistic. The concept of the vagina dentata is found in a number of different folklores and it features heavily in stories about male fears of castration and the attendant loss of power. However, Lichtenstein's film turns the tables on both the traditional vagina dentata legend and the genre horror trope that sexually active young women are marked for death. Instead, Dawn harnesses her sexual power. Her vagina dentata is only dangerous when she resists, resents, or doesn't want sex; when she wants to have sex, when she's enjoying herself, no harm comes to the men she sleeps with. Thus, Dawn's monstrosity becomes a means of empowerment, a means of asserting herself sexually. Far from destroying her, it allows her to navigate the patriarchal world in which she is perceived as a sexual object and to affirm her own subjectivity. Monstrosity itself is transformed and the monster within, the terror of the patriarchal world, is a woman who cannot be coerced into sex.