People Patted by Robot While Conversing Report Better Emotional State

A small study has discovered that people who were touched by a humanoid robot while talking with it later reported an improved emotional state and higher likelihood of complying with a request from the robot.

The findings of the study have been described by Laura Hoffmann from Ruhr University Bochum, Germany, and Nicole C. Krämer from the University of Duisburg-Essen, Germany, in the open-access journal PLOS ONE on May 5^th, 2021.

Interpersonal touch between humans is well-known to have positive impacts, like enhanced immune-system function or decreased stress.

Scientists have started to examine the impacts of physical contact with robots, with certain studies identifying significant effects and others finding no effects. Hence, further study should be carried out to analyze systematically the impacts of robot touch.

As part of the new study, 48 students were hired by Hoffman and Krämer to engage in a school counseling discussion with a humanoid robot (Softbank Robotics’ NAO). During the conversation, for a few participants, the robot shortly and evidently patted the back of the participant’s hand instinctively.

This varied from the design of other studies, which have been dependent on human-initiated touch.

As a response to the robot’s touch, a majority of the participants smiled and laughed, and none of them walked away.

People who were touched were more likely, compared to those not touched, to go along with the robot urging that they have great interest in a specific academic course that was addressed during the conversation.

Participants were asked to do a questionnaire following their conversation with the robot. Participants who were touched by the robot had reported an improved emotional state following their conversation compared to those who were not touched.

But those who were not touched rated their views of the robot and the communication just as positively as those who were touched.

The team came to a conclusion that people were able to experience a positive effect on robot-initiated touch during the conversation. Additionally, the effect on request compliance could be harnessed to make use of robots for motivational causes, for example, to convince people to exercise.

Yet, the authors warn that human-robot interactions—particularly those involving humanoid robots—are complicated, and a lot is still there to be learned about the variations between human and robot touch.

The authors added, “A robot’s non-functional touch matters to humans. Slightly tapping human participants’ hands during a conversation resulted in better feelings and more compliance to the request of a humanoid robot.”

Journal Reference:

Hoffmann, L & Krämer, N C (2021) The persuasive power of robot touch. Behavioral and evaluative consequences of non-functional touch from a robot. PLOS ONE. doi.org/10.1371/journal.pone.0249554.