Between people, eye gaze and other forms of nonverbal communication can influence trust. We hypothesised similar effects would occur during human-robot interaction, predicting a humanoid robot's eye gaze and lifelike bodily movements (eye tracking movements and simulated "breathing") would increase participants' likelihood of seeking and trusting the robot's opinion in a cooperative visual tracking task. However, we instead found significant interactions between robot gaze and task difficulty, indicating that robot gaze had a positive impact upon trust for difficult decisions and a negative impact for easier decisions. Furthermore, a significant effect of robot gaze was found on task performance, with gaze improving participants' performance on easy trials but hindering performance on difficult trials. Participants also responded significantly faster when the robot looked at them. Results suggest that robot gaze exerts "pressure" upon participants, causing audience effects similar to social facilitation and inhibition. Lifelike bodily movements had no significant effect upon participant behaviour.