This paper investigates the automatic recognition of social roles that emerge naturally in small groups. These roles represent a flexible classification scheme that can generalize across different scenarios of small group interaction. We systematically investigate various verbal and non-verbal cues extracted from turn-taking patterns, vocal expression, and linguistic style to model speakers behavior. The influence of social roles on the behavior cues exhibited by a speaker is modeled using a discriminative approach based on conditional random fields. Experiments performed on several hours of meeting data reveal that social role recognition using conditional random fields achieves an accuracy of 74% in classifying four social roles and outperforms the baseline method on all social role categories. Furthermore, we also demonstrate the effectiveness of our approach by evaluating it on previously unseen scenarios of small group interactions.