Under the Hood

Touching The Private Parts Of Robots Arouses People, But Not Like You Think

Nao, the robot
People became physiologically aroused when asked to touch the genitals of a robot, though not when touching its hands and feet. Courtesy of Aldebaran Robotics

So you enrolled in a communications course to fulfill your semester requirements and then you found you could get course credit for participating in an experiment … sweet! In the lab, you sit alone in a room with a toy robot posed on a table before you. Out of nowhere, the thing speaks: “Hello! In this exercise we'll be talking about vocabulary for parts of the body.” Then it asks you to touch it, right between the legs.

If that sounds awkward to you, you are not alone. In a new exploration of contact between humans and robots, Stanford researchers discovered that people became physiologically aroused when asked to touch sensitive parts of a robot, such as the eyes and genitals, though not when they touched its hands and feet.  

What is striking about this experiment is the robot was not some android as imagined by Hollywood, a replication so human it might cause real confusion. Instead, the researchers worked with Aldebaran Robotics’ NAO — a toy-like being that rises a mere 23 inches with functional joints, limbs, head, and hands, though lacking ears, nose, buttocks, or recognizable genitals. Unmistakably artificial, in other words.

What, then, do these results say about us?

“People are not inherently built to differentiate between technology and humans,” explain the authors. “Consequently, primitive responses in human physiology to cues like movement, language, and social intent can be elicited by robots just as they would by real people.”

Physical closeness is essential to our survival and our humanity — infants deprived of touch fail to develop normally. Yet the very same sensation can be perceived as pleasurable or repulsive depending on person, context, and expectation; a simple brush of skin against skin can evoke love, anger, affection, or dislike. Canadian psychologist Sidney Marshall Jourard introduced the term “body accessibility” in 1966 to describe our willingness to allow others contact with our bodies. Jourard looked at the frequency of touches to different parts of the body and concluded the most accessible parts of our bodies include our hands, head, and arms, while the least accessible region is the genitals.

To see if this concept extended to robots, the researchers programmed the NAO to ask people to either point to or touch 13 separate parts of its body. Next, they fitted each of 10 human participants with a sensor measuring skin conductance, a gauge of physiological arousal, on one hand. Then the researchers put the robot and a single participant together in a lab room, where they sat across from one another. Observing, the researchers measured a participant’s reaction time following each robotic request.

When participants touched least accessible areas on the robot, such as its eyes, buttocks, or genitals, they became physiologically aroused yet did not feel the same response when touching most accessible areas, such as the robot’s hand, or when pointing. Based on response times, the researchers discovered that the participants also hesitated when requested to touch the robot’s “intimate” parts. Again, they didn’t hesitate when simply pointing to these same parts or touching any other bodily regions.

“These responses are not simply an act of playing along — they occur on a deeper physiological level,” wrote the researchers, who noted there is an inherent tendency for people to treat robots that seem close enough to human just as they would treat real people. Obviously, this small-scale study involved only a few participants so the results cannot be generalized, fascinating though they may be.

“While they are clearly not human, social conventions such as body accessibility may apply to robots as well,” concluded the Stanford research team, whose work echoes the famous studies of Masahiro Mori, a former professor at Tokyo Institute of Technology.

In the 1970s, Mori first proposed the concept of bukimi no tani, translated as the uncanny valley. No matter how positive the first impression, humanlike robots will eventually inspire a feeling of uncanniness in people at the exact moment when their artificiality becomes evident, Mori hypothesized; even more, this feeling of strangeness ultimately leads to revulsion. The “secret lying deep beneath the uncanny valley,” Mori suggests, is death; the eeriness we feel is instinctive, he says, a primal protection warning us against getting too close to a corpse ... or a different species.

Source: Li J, Ju W, Reeves B. Touching a Mechanical Body: Tactile Contact With Intimate Parts of a Human-Shaped Robot is Physiologically Arousing. The 66th Annual International Communication Association Conference. 2016.