If a total stranger asked you to touch their private parts, you’d probably feel more than a little awkward. Fortunately, this isn’t something humans tend to do very often, although participants in a recent study led by researchers from Stanford University were propositioned by a small robot programmed to engage in just this sort of taboo-busting behavior.

The purpose of this experiment was to see if people’s physiological reactions to touching humanoid robots can mirror their responses to physical contact with genuine humans. Touching the sexy bits of another person, for instance, tends to induce an increase in heart rate as well leave visible traces of one’s awkwardness all over one’s distinctly red face.

As technology advances, interactions between humans and robots are becoming increasingly commonplace, yet the social implications of this are as yet unknown. Obviously, romantic relationships between people and machines are still the stuff of science fiction, although the team behind this latest research wanted to find out if it is possible for humans to become aroused by robots.

To test this, they designed a small humanoid robot programmed to ask people to touch certain parts of its body, as shown in the video below. Each volunteer was fitted with a sensor on one of their hands that recorded their skin conductance – a measure of physiological arousal.

Results showed that when the robot asked to be touched on its “inaccessible parts,” such as its buttocks or genitals, people became more aroused than when touching a more modest part of the robot’s body, like the ears or the hand. Participants also hesitated more when asked to touch the robot’s nether regions, indicating a sense of awkwardness.

The research is set to be presented at the Annual International Communication Association Conference later this year, with the team behind the study claiming their results indicate that “people respond to robots in a primitive, social way.”

This, they say, could have major implications for robot design in the future, leading to possibilities for creating highly social robots capable of providing companionship for humans. Incorporating touch into this relationship may help to reinforce the way that people react to their mechanical peers by inducing physiological reactions, thereby making the connection more real.

How far these relationships can go is still very much undefined, so while ditching your human friends and hanging out with your toaster probably isn’t a good idea, there may well come a time when anyone feeling sad or lonely can simply hug a robot.