Fear is perhaps the most malleable of human emotions, in that it can be both rational and irrational at the same time. Any legitimate fear a person may have — about their finances, health and so on — can be exacerbated with irrationality and horrid fantasies of suddenly coming into ruin or contracting a deadly disease. The human mind can take its gift for fantasy/imagination and apply it to anxieties that are empirically outrageous yet feel incredibly, logically possible. Some of these paranoid fantasies are so tied to the era in which they’re conceived that they fade into history, becoming lore. No one in 2018, for instance, is particularly afraid that someone in their community is a witch. Yet the core of that paranoia, that distrust of other people, is eternally present. In 1954, author Jack Finney exploited that base fear in a story initially published in Collier’s magazine, regarding the populace of a small northern California town being changed literally overnight by alien pods into uncaring, unfeeling, hive-minded creatures intent on taking over the world. Even Finney, at first, didn’t quite hit upon the central terrifying metaphor of his story — the initial title he conceived was “A Fall of Small Frogs,” referring to natural occurrences throughout history that are unexplainable to humans. Fortunately, he eventually realized that the concept at the story’s heart, the loss of one’s individuality and humanity, was the most powerful, and retitled the work “The Body Snatchers.” With that, he created one of the most enduring concepts in the history of science-fiction and horror, one that can and has been applied by filmmakers to American life over the span of 60 years without its power and resonance ever being diluted.

Made in 1955, and released in early 1956, the first cinematic adaptation of “The Body Snatchers” took the premise of Finney’s story and made it immortal. Producer Walter Wanger optioned the rights to the novel, then a magazine serial, before Finney was even done publishing it, recognizing right away the potential of the material. It perfectly exploited one of the primary anxieties of the 50s, the fear that a threat was already alive and well within America, and that even people in a close-knit small town couldn’t trust each other. Finney’s original novel is surprisingly optimistic, as it concludes with lovers Miles and Becky burning a field of alien pods, and watching the seeds drift away into space — the aliens essentially give up in the face of human resilience and determination. Director Don Siegel and screenwriter Daniel Mainwaring’s take is decidedly bleaker: their film features small town doctor Miles Bennell (Kevin McCarthy) and his fellow divorcee Becky Driscoll (Dana Wynter) logically dismissing the truth of what’s happening in their little town of Santa Mira, California until it’s too late. The film presents events in such a manner as to credibly show just how easily and quickly an invasion of this type could occur, with Miles, Becky and their friends being gaslighted by the pod people into doubting their instincts. Siegel and Mainwaring take great care to show exactly what’s at stake, which is nothing less than the eradication of humanity as a concept, with the pod people having no individuality, no hate and no love. This idea is presented as a seductively desirable notion by Dr. Kauffman (Larry Gates), advocating for race-wide conformity as a way to let go of individual troubles. In this, Siegel and Mainwaring wander right into a notion that hits a raw nerve with not just the political era the film was made in, but with humanity itself. As an attack on society, as well as an argument for individuality, their pod people are an existentialist horror so understandable and so palpable that McCarthy and Wynter can’t possibly oversell the fear they portray on screen. Siegel’s film is not pointedly political (he apparently loved the idea that both the right and the left could make arguments that it’s on their side), yet its purpose is abundantly clear. Despite a tacked-on ending mandated by the studio that provides some element of hope (even though the very final shot, of a worried Miles, subverts this a bit), the enduring image of Invasion of the Body Snatchers is of McCarthy’s Bennell screaming at oblivious drivers on a highway at night, “They’re here already! You’re next!”

Siegel’s version put the term “pod person” into the American lexicon, and 22 years later, director Philip Kaufman and writer W.D. Richter redefined it. Their 1978 interpretation, Invasion of the Body Snatchers, translated Finney’s small town suburban anxieties to modern urban paranoia. The scenes of Donald Sutherland’s Bennell, now named Matthew, moving through San Francisco trying to report his suspicions about pods duplicating people were shot by cinematographer Michael Chapman holding a camera wrapped in his coat, capturing the throngs of real people on the streets. The result, thanks to the context, is a vision of overwhelming, oppressive menace. That sensation is helped greatly by the overlapping dialogue and sound effects by Susan Crutcher and Ben Burtt made in a New Hollywood style, akin to other paranoid thrillers of the 70s like The Conversation (1974) and Three Days of the Condor (1975). This, plus scenes involving clandestine meetings with shady authority figures, and the general sense that most government agencies have been infested with pods, is perfectly evocative of the post-Watergate, post-Vietnam era. Kaufman and Richter combine that with a nod toward the then-current fads involving pop psychology and personality cults, as the Dr. Kauffman character from the 1956 film becomes Dr. David Kibner, a self-help guru who dismisses the worries that the protagonists have about pod people as expressions of neuroses. Kibner, of course, is revealed to be a pod himself, likely from the very start. For an audience just coming out of the hippie-free love-counterculture era, Kaufman’s “invasion” is one of individualist-sapping conformity, a reflection of big business taking over the world, presciently predicting the corporate culture of the late 1980s. More than anything else, Kaufman’s version endures thanks to its pitch black ending — you can fool the pods by pretending to be like them, but they’ve already won, and, sooner or later, you will be one of them.

The most recent two iterations of Finney’s story have their flaws as films, but still manage to propagate the original story’s themes while tying their versions to their respective eras. Body Snatchers (1993), directed by sleaze guru Abel Ferrara and written by, among others, B-movie kings Larry Cohen and Stuart Gordon, is bizarrely the most basic and tame version of the franchise films. This movie feels less like a remake (there’re no real analogues for the novel’s characters, for instance) and more like a sequel, repeating elements from Kaufman’s film (the pod peoples’ warning shriek upon finding a human chief among them) and assuming the audience already has a basic familiarity with the concept, proving just how prevalent “pod people” had become in pop culture at that point. Its major innovation, that it takes place in a military base, does speak to the Desert Storm-obsessed early 90s, exploiting the notion of willful conformity in military life to the forced conformity of the pods. Much more successful as a modern update of Finney’s story is 2007’s The Invasion, adapted by writer David Kajganich (Suspiria). The movie is structurally and tonally uneven, thanks to production issues causing it to be directed by Oliver Hirschbiegel with additional reshot scenes by director James McTeigue and written by the Wachowski sisters. Despite that, it reimagines Finney’s pods as an alien virus, behaving analogously to the flu, infecting humans and changing their DNA while they sleep. In that way, it makes the metaphor of the pod people more literal, in that people aren’t being replaced with duplicates, but changing internally, the spread of conformity being an explicitly viral one. Kajganich’s script focuses heavily on the point espoused by prior pod characters that a world run by pods would be inherently peaceful, and that to be human is to be violent, hateful and destructive. It’s a viewpoint as bleak as the 1978 version, and while the film pulls its punches too much to really let it land, it’s still a perfect allegory for the early/mid-2000s, when people lost faith not just in their government but in themselves.

Ultimately, the endurance of Finney’s story and the concept of “pod people” can be attributed to the fact that it’s not a metaphor for any one fear, but rather dozens. Becoming a pod person can stand as an indictment of any political viewpoint, as well as social and cultural views that are considered harmful or backward. As long as human beings continue to strive for balance and perfection, the definition of behavior that is most human (as well as most inhuman) will always change, and the loss of any of that humanity is something to be feared. Humanity will always be a balance between our intelligence and our more animal natures — author and professor Vivian Sobchak, interviewed in a featurette on The Invasion blu-ray, says that “We pride ourselves on being rational, and somehow the extension of rationality to the fear that being too rational, being a culture which depends too much on science and technology and an empirical approach to everything, we’ll somehow lose something in the process.” Conformity can look like many things, from basic lifestyle tastes to subscribing to beliefs that authority figures dictate. Perhaps the most terrifying element of Finney’s concept lies in its transformative catalyst: sleep, due to its necessity and inevitability. No matter what, sleep comes for us all. The question is, do we have the strength to wake up?

Bill Bria (@billbria) is a writer, actor, songwriter and comedian. ‘Sam & Bill Are Huge,’ his 2017 comedy music album with partner Sam Haft, reached #1 on an Amazon Best Sellers list, and the duo maintains an active YouTube channel and plays regularly all across the country. Bill‘s acting credits include an episode of HBO’s ‘Boardwalk Empire’ and a featured parts in Netflix’s ‘Unbreakable Kimmy Schmidt’ and CBS’ ‘Instinct.’ His film writing can also be seen at Crooked Marquee as well as his own website. Bill lives in New York City.