  A challenge in using robots in human-inhabited environments is to design
behavior that is engaging, yet robust to the perturbations induced by human
interaction. Our idea is to imbue the robot with intrinsic motivation (IM) so
that it can handle new situations and appears as a genuine social other to
humans and thus be of more interest to a human interaction partner. Human-robot
interaction (HRI) experiments mainly focus on scripted or teleoperated robots,
that mimic characteristics such as IM to control isolated behavior factors.
This article presents a "robotologist" study design that allows comparing
autonomously generated behaviors with each other, and, for the first time,
evaluates the human perception of IM-based generated behavior in robots. We
conducted a within-subjects user study (N=24) where participants interacted
with a fully autonomous Sphero BB8 robot with different behavioral regimes: one
realizing an adaptive, intrinsically motivated behavior and the other being
reactive, but not adaptive. The robot and its behaviors are intentionally kept
minimal to concentrate on the effect induced by IM. A quantitative analysis of
post-interaction questionnaires showed a significantly higher perception of the
dimension "Warmth" compared to the reactive baseline behavior. Warmth is
considered a primary dimension for social attitude formation in human social
cognition. A human perceived as warm (friendly, trustworthy) experiences more
positive social interactions.
