The classical experimental methodology is ill-suited for the investigation of the behavioral and physiological correlates of natural social interactions. A new experimental approach combining a natural conversation between two persons with control conditions is proposed in this paper. Behavior, including gaze direction and speech, and physiology, including electrodermal activity, are recorded during a discussion between two participants through videoconferenc-ing. Control for the social aspect of the interaction is provided by the use of an artificial agent and of videoed conditions. A cover story provides spurious explanations for the purpose of the experiment and for the recordings, as well as a controlled and engaging topic of discussion. Preprocessing entails transforming raw measurements into boxcar and delta functions time series indicating when a certain behaviour or physiological event is present. The preliminary analysis presented here consists in finding statistically significant differences between experimental conditions in the temporal associations between behavioral and physiological time series. Significant results validate the experimental approach and further developments including more elaborate analysis and adaptation of the paradigm to functional MRI are discussed.