A QRIO, modified to respond to social touching with giggles, attended a kindergarden class and became accepted by the human children:
In the study, QRIO was introduced into a classroom of toddlers aged 18 months to 24 months. Children of this age group were chosen because they have no preconceived notions of robots and they communicate using touch as much as speech.
“The children accepted the presence of QRIO very well,” Movellan told LiveScience. “There were a few children who were very interested but maintained distance. Over time, the relationship between children and QRIO evolved positively.”
In phase I of the experiment, which lasted 27 sessions, QRIO was instructed to interact with the children using its full behavioral repertoire, which included head-turning, dancing and giggling. At first, the children would touch the robot on its face, but as they warmed to him, the majority of their touches were to its hands and arms â€” a pattern the children also displayed toward each other.
During phase II, which lasted 15 sessions, QRIO ignored the children’s touches and danced throughout the session. “At that point, the [children] quickly lost interest,” Movellan said.
When QRIO’s ability to respond to touch and giggle were returned for three sessions in phase III, the children became friendly with the robot again.
When robot’s batteries died and it laid on the floor, some of the children cried.
Others put a blanket over him and said, “nigh-nigh.”
And further down in the same article:
The ability to respond to touch is relatively easy to program into robots, Movellan said. “We had things like computer vision in the robot, and touch was the easiest thing,” he said. “And it turned out to be the most important to get things going.”
A lot of energy is focused on developing computer vision, neural networks, and other AI-type technology, which is great. But touch interfaces are inexpensive, relatively easy to engineer, and very effective at engaging human emotion. I think this study implies that, for the purposes of social acceptance, touch may be the most important human-robot interaction mode.