Importance of Touch for Conveying Affection in a Multimodal Interaction with a Small Humanoid Robot

To be accepted as a part of our everyday lives, companion robots will require the capability to communicate socially, recognizing people's behavior and responding appropriately. In particular, we hypothesized that a humanoid robot especially should be able to recognize affectionate touches conveying liking or dislike, because the humanoid form elicits expectations of a high degree of social intelligence, providing affection can contribute to people's quality of life, and people will seek to show affection by touching a robot because such behavior is fundamental and crucial for human bonding. This hypothesis needed to be verified because robots are typically not soft or warm like humans, and people can communicate through various other modalities such as vision and sound. The main challenge faced was that people's social norms are highly complex, involving behavior in multiple channels. To deal with this challenge, we adopted an approach in which we analyzed free interactions and also asked participants to rate short video-clips depicting human-robot interaction. As a result, we verified that touch plays an important part in the communication of affection from a person to a humanoid robot considered capable of recognizing cues in touch, vision, and sound. Our results suggest that designers of affectionate interactions with a humanoid robot should not ignore the fundamental modality of touch.