— In this study, we examined how participants (N=20) interacted and collaborated with a set of robotic drawers to accomplish an assembly task. The drawers’ behavior varied along two dimensions – proactivity and expressivity of motions. The results of our study indicate that participants consider an expressive robot to be more involved and interested in the interaction. We also found that while proactive or expressive robots could dominate the interaction, proactivity might negatively affect the participants’ perception of their social status relative to that of the robot’s, while expressiveness did not. This shows the importance of utilizing expressive movements when designing socially appropriate robots that collaborate with human users.