The GreenDot Project aims to train software to recognize a person by the unique fingerprint of body language. New York University computer science professor Chris Bregler tells me that the GreenDot Project "is DOD funded for some biometrics application, but we also applied it to lots of public figures, including the current Presidential candidates." From the project page:
The goal of the project is to train a computer to recognize a person based on his or her motions, and to identify the person's emotional state, cultural background, and other attributes. The research is federally funded (by the Office of Naval Research and the National Science Foundation), and conducted by an interdisciplinary team of computer scientists, movement experts, linguists, and other specialists. The current focus is the analysis of national and international public figures while they are giving speeches, with future plans to investigate many other domains. The research team is building a large database of people's motions, using cable television recordings and web video downloads. Through techniques similar to those used in speech recognition, this project applies machine learning (an Artificial Intelligence technique) to train a computer system to compare the detected body language of an individual in a video, to that of a database of other subjects.