Human facial displays are dynamic in nature, in that§they move in space and time. Understanding the§dynamic course of facial expressions has important§implications for social communication in everyday§life. Additional information can be extracted from§moving displays that goes beyond that contained in§static displays. However, the signal value of dynamic§information is poorly understood, and scientific§knowledge regarding the effects of dynamic displays§on social judgements is still lacking. §In this dissertation, I examine the role played by§dynamic information in the interpretation of facial§expressions, particularly with respect to their§perceived authenticity. Using a range of social§settings, the central assumption tested is that§perceivers are sensitive to the temporal quality of§expressions and take this information into account§when making attributions and decisions. The findings§of this research provide insights into the inferences§perceivers make on the basis of dynamic displays, and§have implications for psychologists, sociologists,§economists, and computer scientists.