Humanoids have long been regarded as the ‘holy grail’ but there’s room for a lot more diversity in the robot design world.
In August of 2021, Tesla CEO Elon Musk revealed his company’s plan to produce a humanoid robot called ‘Optimus’. The announcement, accompanied by a dancing actor in a skintight robot costume, was ridiculed by sceptics, but Tesla is not alone in the quest to create human-shaped machines.
Research labs and companies around the globe are investing serious amounts of money in these complex robots, for uses from warehouses to nursing homes. Their pitch is two-fold: the human form is relatable, and it fits seamlessly into our existing infrastructure. These reasons are sensible, but there might be a better way forward.
Humanoids, sometimes called the ‘holy grail’ of robotics, are robots with a torso, two legs, two arms, and a head. Google image search the word ‘robot’, and your browser will fill with pictures of humanoids.
Some robot creators argue that the autonomous machines we’ll interact with in the future need to look like us, because we relate best to other humans. I’ve found in my own research that we connect emotionally with machines onto which we can project our own traits, but the notion that we most relate to a human shape may be missing something.
People name their robot vacuum. Would they like it better if it was a humanoid that walked around vacuuming? Probably not. When something has a human form, we have very different expectations for its intelligence and how it will perform. Our current robots don’t live up to those expectations, nor will we have a robot butler anytime soon.
Fortunately for robot designers, things don’t need to be humanoid for us to relate to them – they just need to mimic cues that we recognise. Artists and animators have honed the art of capturing our emotional expression and then putting it into other shapes – think Bambi, Cars, or the Pixar lamp.
Japanese cities have attracted visitors with mascots like Kumamon, a simple, cute bear character created by the government of Kumamoto Prefecture to boost tourism. And thousands of Star Wars fans love R2-D2, who is basically a tin can on wheels and is yet more emotionally compelling than most humanoids.
Avoiding the human form when designing robots not only avoids the problem of expectation management, it can also side-step a minefield of social injustices. For example, researchers from the University of Bielefeld, Germany, found that people will rate a humanoid robot with long hair better suited for stereotypical female tasks like household and care work and less suitable for doing technical repairs, compared to an identical robot with short hair.
Previous studies have also shown that artificial agents with human faces are seen as more attractive, trustworthy, persuasive, and intelligent when they’re of the same ethnicity as the person rating them. Technology that looks too human not only reflects our biases, it can also entrench and perpetuate harmful stereotypes.
There’s also the logistical argument for humanoid robots: we live in a world built for humans, with stairs and door knobs and narrow passageways. In order to navigate these spaces, some designers say, we need robots that are built like us. It’s certainly true that many spaces are difficult to navigate with wide bodies, wheels, or treads. But as we look to the future, maybe there are better choices.
Robots can be smaller than the eye can see, or larger than a house. They can be encased in metals or soft materials. They can roll, climb, slither, jump, or ooze from point A to B. According to roboticist Prof Robin Murphy of Texas A&M University, the best form is “whatever shape gets the job done.”
Ironically, challenging the notion that the ‘right way’ to do things is the way humans do them creates opportunities to reach broader human demographics, specifically people who often find themselves left out of the design process entirely.
Laurel Riek, a roboticist at the University of California, San Diego, has pointed out that rather than throwing our funds into expensive, difficult-to-engineer, bipedal humanoid robots, we could invest in making infrastructure more friendly for wheelchairs, walkers, and strollers. If a wheelchair can access a space, so can a simple and efficient robot on wheels.
Human beings are far from uniform in our construction and abilities, and if we design our world to reflect that, we could radically increase accessibility at the same time as developing better, cheaper robots with a greater range of skills. And besides, why take the stairs when you can climb the walls?
While there will always be some use cases for humanoid robots, we may be able to do better for work, companionship, and society than replicating what we already have. As robots move from behind factory walls into shared spaces, robotics provides us a wonderful opportunity: it allows us to think outside of ourselves, not only in designing our robots, but also in our ideas for how to construct a better world.