In a robot apparatus, the storage capacity necessary for holding motion
data is diminished in representing the emotion by motions exploiting the
body resources. In demonstrating component behaviors of the robot
apparatus, the basic posture, as the posture at the start time of one or
plural movements forming a component behavior, is changed to express the
emotion. Specifically, the robot apparatus includes variations for
expressing the emotion for the basic posture (basic posture for the
emotion). The respective resources are actuated from the basic posture
for the emotion and reversion is made again to the basic posture to
demonstrate the emotion. At this time, the robot apparatus 1 holds data,
such as joint angles, in the course of the movements.