Ridley Scott’s 1982 science fiction masterpiece, Blade Runner, opens with a man named Holden administering a test to Leon, an employee of the Tyrell Corporation. Holden says, “You’re in a desert. You’re walking along in the sand when all of a sudden…you look down and see a tortoise. You see a tortoise, Leon.  It’s crawling toward you…You reach down and flip the tortoise on its back, Leon. The tortoise lays on his back, his belly baking in the hot sun, beating its legs trying to turn itself over, but it can’t, Leon, not without your help. But you’re not helping…. Why is that, Leon?”

Holden is a Blade Runner, a specially trained police officer designed to hunt down and “retire” state-of-the-art androids called replicants. This question about the tortoise, and later questions about Leon’s mother, are part of the Voight-Kampff test, a test designed to evoke emotional responses and determine whether someone is a replicant. Leon, it turns out, is a replicant—one who did not appreciate Holden’s questions and killed him, rather than completing the test.

[spoilers about Blade Runner and Ex Machina follow]

But as the remainder of the film shows, the boundary between human and replicant is quite an ambiguous one. Another Blade Runner named Deckard (Harrison Ford) is hired to hunt down Leon and his three compatriots, all of whom are the most sophisticated model of replicant available and are illegally searching for a way to extend their lifespans. During the course of his search, Deckard meets Rachel (Sean Young), a replicant who believes she is human because she has had memories implanted; it takes Deckard over 100 questions in the Voight-Kampff test, compared to the usual twenty or thirty, to determine that she is a replicant. Near the end of the film, Deckard and Roy (Rutger Hauer), the leader of the group of four replicants, confront each other on a rooftop; in perhaps the most famous line from the film, Roy laments what will be gone when he dies:

I’ve seen things you people wouldn’t believe. Attack ships on fire off the shoulder of Orion. I watched C-beams glitter in the dark near the Tannhauser gate. All those moments will be lost in time... like tears in rain....Time to die.

The poetry and memorability of this line belies Roy’s existence as something less than human, as does Roy’s willingness to spare Deckard’s life, even in the face of Roy’s own certain death.

The most noteworthy blurring of the boundary between replicant and human, however, comes in the character of Deckard himself. At the end of the film, another police officer named Gaff leaves an origami unicorn on Deckard’s doorstep. In both the Director’s Cut (1992) and Final Cut (2007) versions of the film, Deckard has had a dream of a unicorn running through the forest.The origami unicorn is widely interpreted to mean that Gaff knows Deckard’s dreams and memories because Deckard himself is a replicant. Rather than administering the test on others, Deckard should have been the subject of the Voight-Kampff test himself.

While itself completely fictional, the Voight-Kampff test bears some resemblance to Alan Turing’s 1950 proposal for measuring artificial intelligence—what is known today as the Turing test. Turing did not seek to measure emotional responses, as the Voight-Kampff test does; rather, he proposed evaluating conversations between a human and a machine to see how well the machine could mimic human speech patterns. This test, which Turing introduced in his paper “Computing Machinery and Intelligence,” does not measure whether machines can think, but instead, how well an artificial intelligence can play “the imitation game” (433).

The idea of the Turing test plays a central role in Alex Garland’s 2015 film, Ex Machina. This film tells the story of Caleb Smith (Domhnall Gleeson), a man who works for a company resembling Google and who wins a company-wide contest to meet the reclusive CEO, Nathan Bateman (Oscar Isaac). Caleb travels to Nathan’s estate, and, after signing a very restrictive non-disclosure agreement, learns why he really has been brought to what seems like the middle of the wilderness: to test out a form of artificial intelligence (AI) that Nathan has developed. Nathan tells Caleb that he “will be the human component in the Turing test…[and] if that test is passed, you are dead center of the greatest scientific event in the history of man.”

When Caleb meets the artificial intelligence—a humanoid robot named Ava (Alicia Vikander)—he quickly realizes that this is no ordinary Turing test. He is already aware that she is a robot, so he wouldn’t be able to objectively measure her skills of language imitation. Nathan agrees, and tells Caleb that what he is looking for is something more subjective: “If I hid Ava from you so you just heard her voice, she would pass for human. The real test is to show you that she’s a robot, and then see if you still feel she has consciousness.” Nathan, it becomes clear, is looking for more than what Turing’s original test would measure—the ability to imitate human speech—and is instead looking to test for actual intelligence.

But the longer Caleb stays at Nathan’s estate, and the more he participates in this test of Ava, it becomes clear that the boundary between Caleb’s humanity and Ava’s status as a machine is blurry. In their initial meeting, Caleb asks Ava to tell him about herself, saying that she can start anywhere because he’s “interested to see what she will choose.” During their second meeting, Ava turns these same words—slightly sarcastically—back on Caleb, highlighting the inequality of their relationship and demonstrating, as Caleb later tells Nathan, “an awareness of her own mind, and also of awareness of mine.”

The boundary between human and AI blurs even further when Ava starts flirting with Caleb. When Caleb first meets her, Ava looks mostly robotic in form, with wire mesh covering most of her skull and body and only her face appearing to be human. As Caleb begins to recognize her self-awareness, Ava responds by putting on a dress and a wig that she thinks he will like and suggests that they go out on her ideal version of a date—a visit to a busy intersection so she could people-watch. Despite his discomfort with the idea, Caleb grows sexually attracted to Ava, and with this introduction of sexual tension, the tone of the movie begins to grow more sinister. Power outages lead to lockdowns. Nathan stays up late at night, drinking in dark rooms and surprising Caleb when he enters. Caleb discovers older models of Nathan’s AI—all female—in closets in Nathan’s room, with human-like skin seamlessly fit over mesh frames. This psychological manipulation has Caleb questioning his own humanity, to the extent that he cuts his own arm open with a razor to confirm that he, unlike the models in Nathan’s closet, will bleed.           

Together, Caleb and Ava begin to plan how they could escape from Nathan’s compound, and just when it seems that they might be successful, Nathan reveals to Caleb that Caleb wasn’t administering the test; he was the test. Nathan tells Caleb, “Ava was a rat in a maze, and I gave her one way out. To escape she’d have to use self-awareness, imagination, manipulation, sexuality, empathy, and she did. Now if that’s not true AI, what the fuck is?” By manipulating Caleb, Ava was able to convince him to help her escape, thus demonstrating that he viewed her as an intelligent, conscious being.

Yet Ex Machina is not just a film about a man who serves as a test for AI. It can also be seen as a Turing test all on its own, a test of the very viewers of the film. At the end of the movie, Ava and Caleb have successfully implemented their plan to override the lockdown mechanism, and Ava kills Nathan, puts on synthetic skin so that she looks fully human, and leaves Caleb locked in the compound. As she finally steps outside and travels to a busy intersection full of people, Ava calls to mind a thought-experiment that Caleb described earlier in the film. In this thought-experiment, a woman named Mary is born in a black and white room and only knows about color second-hand. One day, Mary steps outside and finally sees the blue sky. The purpose of this story, Caleb explains, is to show the difference between a computer and a human mind: “The computer is Mary in the black and white room. The human is when she walks out.”

With this unexpected ending, we as viewers are left to wonder how we view Ava, and as a result, where our sympathies lie. Do we see Ava as a horrifying, immoral computer? Or do we see instead a story of a woman who has achieved her freedom? Like both Caleb and Ava, we, too, are being tested, to see how far we will extend the boundary of humanity.

While this particular plot might still seem firmly within the realm of science fiction, it is worth pausing for a moment to consider how much we trust artificial intelligence in our everyday lives. We ask Google Maps how to get to that new restaurant. We ask Siri what the weather is, or who the prime minister of India is. We trust Netflix to recommend movies and Goodreads to find our next book. We’ve probably all been in a situation where we have trusted a machine more than a human—whether it’s trusting GPS more than our spouse to provide directions, or using Wikipedia to fact-check what someone tells us at a party.

Certainly, there are significant differences between these examples and a full-fledged AI like Ava, and this essay is not meant to be a warning against the dangers of technology. Rather, it’s a reminder that tests like the Voight-Kampff test and the Turing test exist because the boundary between human and machine is a fluid one, with influence working both ways. Our daily interactions with Google, Siri, and countless other forms of contemporary AI don’t just shape the computer algorithms; they shape how we think, too. And, perhaps even more importantly, whether it’s a targeted ad from Amazon, a thermostat that adjusts the temperature when we arrive home, or almost any app on our smartphones, the ubiquity of this technology shows that science fiction is no longer the only place where we should grapple with the implications of the blurring of this boundary. These aren’t questions for the future—these are questions for now.

Jennifer L. Miller teaches English at Normandale Community College in Minneapolis, Minnesota.

Works Cited

Blade Runner. Directed by Ridley Scott, Warner Brothers, 1984. Final Cut edition, 2007.

Ex Machina. Directed by Alex Garland, Universal Pictures, 2015.

Turing, Alan. “Computing Machinery and Intelligence.” Mind, vol. 59, no. 236, October 1950, 433–460.