Elenoide the android was made to shake your hand. She looks like a Madame Tussad’s rendition of a prim fifth-grade teacher. She’s dressed in a salmon cardigan with scalloped edges, a knee-length striped skirt, and a wig made of ashy blonde human hair. Her hands are warmed by heating pads hidden beneath the palms. During experiments, she wears white butler gloves.
Ruth Stock-Homburg, who studies human-robot interactions at the Technical University of Darmstadt in Germany, enlisted Elenoide—who was originally built in Japan—to participate in a kind of physicalized Turing test last year. In a series of trials, she positioned Elenoide beside a real person (also wearing the butler gloves) and instructed a blindfolded participant to shake each of their hands. If the participant couldn’t discern which hand was skin and bone and which was plastic and pneumatics, Elenoide would pass. Only four of the 15 participants were fooled; the remaining 11 thought her hand was too stiff and its warmth too uneven, meaning Elenoide largely failed to escape the tactile uncanny valley and become a perfect flesh-pressing simulacrum of humanity. But Stock-Homburg hasn’t given up. Not even now, when the very idea of clasping hands—of using physical touch to establish and cement social bonds—teeters toward taboo.
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The Covid-19 pandemic has upended social norms, especially greetings. In France, the government has warned against cheek kissing. In New Zealand, a Maori tribe has banned the traditional hongi greeting, in which people press their noses together and inhale each other’s breath. Throughout the West—and in business settings all over the world—the handshake has been the primary casualty. “I don’t think we should ever shake hands ever again, to be honest with you,” Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said in April. The vast majority of Americans approve of and are willing to comply with such social distancing measures, it seems, but the handshake is mourned in a way that crowding into an elevator is not. “The handshake is the most widely used gesture for making promises and agreements,” Stock-Homburg says. “It’s quite socially important.” The empty space its loss creates in polite social interactions is important, too.
Fauci is not the first person to recommend jettisoning the handshake entirely. Hands are dirty and proven vectors of disease transmission, so coming into contact with fewer of them on a daily basis might be good for your health. Fauci thinks it might even reduce the rates of other infectious diseases, like influenza. Germaphobes—and some medical professionals—have been saying as much for years. Mark Sklansky, a pediatric cardiologist and self-described germaphobe, has been waging war on the handshake in health care settings since the early 2000s. “People laughed at me,” Sklansky says. “They’d say, ‘Listen, get over it.’” Sklansky didn’t get over it. In 2014 he even rewrote the lyrics to the 1970s country hit “I Can Help” to make it an anti-handshake PSA, and posted it on YouTube.
Sklansky argues that the reasons to abandon the handshake extend beyond disease transmission, although that should be enough. “Many people don’t like shaking hands for cultural or religious reasons,” he says. Some Muslim people, for example, refrain from touching members of the opposite sex during greetings. “There’s a power dynamic in a medical setting,” Sklansky says. “The patient may not want to upset the doctor. They may feel compelled to shake hands. I don’t think that’s right.” According to Leonard Mermel, who studies the prevention and control of infectious diseases at Brown University, the opposite is also true: Studies have shown that most patients expect and want a handshake from their doctor, so doctors are trained to do it.
The same social tensions exist outside of hospitals too. Imagine rebuffing a potential boss or employee’s handshake at the end of a job interview. At the very least, it’s awkward, as handshakes often are. They’re a highly prized and strictly judged bit of social choreography. Too soft and you’ll be declared a limp fish. Too hard and you’ve got something to prove. You might not experience the handshake as a Turing test the way Elenoide did, but they’re always something to pass or fail.
Yet the handshake endures, as it has for millenia. No one knows exactly where and how the handshake started, but it is ancient. Examples of handshakes in art date back to at least the ninth century, to a relief of a Babylonian and Assyrian ruler sealing an alliance. People theorize that the gesture may have begun as a demonstration that your hands held no weapons. (In the context of Covid-19, it’s your hand that’s become the weapon.) It’s popularity in America might stem from the 18th-century Quaker preference for the gesture over what they saw as less democratic alternatives like bowing. Now it’s the standard greeting in the Western and international business worlds—although, as President Trump’s joint-wrenching handshakes with other world leaders show, they’re not always peaceable or democratic.
Handshakes are not valued equally among all the social and cultural groups that practice them. According to Yuta Katsumi, a cognitive neuroscientist who currently researches memory but has conducted several studies on people’s evaluation of handshakes, everyone he studied appreciated a handshake. They were taken as a sign of goodwill and trustworthiness and business competence. However, Katsumi saw one group’s brains light up more than all the others when they witnessed a good, firm handshake: men, and white men in particular. “There’s a good amount of evidence that handshakes are a male activity,” Katsumi says. “If you do an observational study, male-male interactions involve a handshake much more frequently than female-female or mixed-gender interactions.” A quick Google search will reveal articles cataloging multiple strains of gendered handshake angst. There are worries about grip strength, chronicles of boardroom handshake snubs, advice columns urging women to engage in flesh pressing and for men to tone down the macho bone-crusher routine when dealing with their colleagues.
Small wonder robots have such trouble. Stock-Homburg, along with her colleagues Moritz Arns and Clément Gosselin, chose the handshake not only for its importance but also for its complexity. The robot has to recognize a hand, move toward it precisely, grasp, squeeze, and pull away. (All of those steps are difficult, but Arns and Gosselin found simulating squidginess to be among the most difficult. “When you grasp the hand and squeeze, you expect it to deform quickly,” Gosselin says.) It’s the intangible sum of all elements—precision, grasping force, speed, fluidity of motion—that creates the illusion of humanness, and with it the illusion of personhood and the understanding of the gesture’s cultural weight. “For me, it describes an incredibly important power balance,” says Arns. “It’s more than the speed and grasping force. I don’t know of any other gesture which provides this insight in that short moment.” For a human-robot handshake, it’s not clear what that insight would be.
The people training these Turing-ready hand shakers think that it’s the squishy cultural meaning, the simulation of intimacy and insight, that makes the endeavor worthwhile, especially right now. “Robots are more accepted the more natural they behave,” Stock-Homburg says. “Robot acceptance is the key … because they are an important means to avoid infection.” Acceptance will only get more important if the robots become stand-ins for human workers as well as coworkers. Stock-Homburg envisions robots in retail settings, in hospitals, wandering the empty halls of office buildings while human workers stay home. Gosselin sees robotic handshakes as a way to facilitate virtual communication, with humans on each side controlling and interacting with a robot hand. “The general goal was to be able to provide interaction between a therapist and a client remotely,” he says. “Or between a teacher and student.” The touch, Gosselin says, gives people something to relate to—though being a long-distance puppet master (and having a disembodied arm in your office) seems rather eccentric.
Given how culturally fraught the handshake is, dispensing with it might be simplest for everyone. “It could be the moment for Western society to step back, reassess, and think of another greeting to convey trust that doesn’t require a handshake,” Mermel, the infectious disease specialist, says. Even as social-distancing restrictions loosen, Mermel thinks that, from a public health standpoint, it’s best to maintain a hands-off approach. And if humans aren’t shaking hands, it won’t make sense for robots to, either. Maybe the research that’s been done so far could be rerouted toward robo-elbow bumps—which has the benefit of feeling more awkward (more robotic) than a handshake anyway. Also, it will save a fortune on robot hand sanitizer.
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