Self-disclosing one's life experiences is known to be beneficial to the psychological health of older adults, from the viewpoint of integrity. It has been shown that people tend to self-disclose more to the people they are fond of. For improving interpersonal liking, the use of the “gain effect” has been shown to be effective. “Gain effect” refers to that people like a person who initially has a negative attitude but gradually develops a positive attitude, compared to a person who consistently has a positive attitude. Based on these previous studies, our study aims to clarify the effect of a change in the robot's listening attitude on the self-disclosure of the elderly. We conducted an preliminary experiment, wherein 15 elderly participants self-disclosed to a robot for approximately 20 minutes. The participants were assigned to one of three groups according to the type of robot they self-disclosed. 1) The CN group where participants interacted with the robot that consistently listened with neutral behavior, 2) the CP group where participants interacted with the robot that consistently listened with positive behavior, and 3) the Ch group where participants interacted with the robot that listened with neutral behavior first and subsequently with positive behavior. The results revealed that the Ch group participants' ratio of self-disclosure utterances was the highest among the three groups. Furthermore, the willingness to self-disclose tended to be higher for the Ch group than for the CN group, in terms of everyday experiences and loss experiences.

The current study investigated the effect of a robot's gaze direction while not engaged in any tasks (i.e., while "idle") on users' comfort and subjective impressions of the robot. We predicted that users would feel differently when the robot looked at the same objects as the user (i.e., during joint attention between robot and user) or not, even when the robot's gaze direction was the same. We conducted an experiment in which participants watched a video clip five times in five different robot gaze direction conditions. To examine the effects of joint attention, participants were divided into two groups by the distance from the monitor on which the video was presented. Joint attention between the robot and participant occurred in different robot gaze directions between the two groups. We measured participants' comfort, subjective impressions of the robot, and related variables. The results revealed that the robot's gaze direction affected participants' comfort and subjective impressions among participants 75 years old and above. However, we found no effect of joint attention. Additionally, participants felt most comfortable and had the most positive impressions of the robot when it looked at a monitor on which participants did not watch the video clip.