  Increasing anthropomorphic robot behavioral design could affect trust and
cooperation positively. However, studies have shown contradicting results and
suggest a task-dependent relationship between robots that display emotions and
trust. Therefore, this study analyzes the effect of robots that display
human-like emotions on trust, cooperation, and participants' emotions. In the
between-group study, participants play the coin entrustment game with an
emotional and a non-emotional robot. The results show that the robot that
displays emotions induces more anxiety than the neutral robot. Accordingly, the
participants trust the emotional robot less and are less likely to cooperate.
Furthermore, the perceived intelligence of a robot increases trust, while a
desire to outcompete the robot can reduce trust and cooperation. Thus, the
design of robots expressing emotions should be task dependent to avoid adverse
effects that reduce trust and cooperation.
