Foster says that they can tell that Officer Farr is lying because his voice pitch rose from fear to surprise. Voice pitch does go up in fear, but I don’t know of research that shows it goes up even higher when fear switches to surprise. And even if that were so, it would not, for me, be sufficient to make the judgment of lying. People under suspicion who are truthful can be afraid of being disbelieved – it is not just the perpetrator who is afraid.
Usually the relationship between fear and surprise is reversed from what Foster claims here. The anthropologist Karl Heider when studying the language used for emotional experience among Indonesians proposed that there are waystation and endpoint emotions. Surprise is almost always a way station, changing quickly into some other endpoint emotion. Fear can also be a waystation leading to anger as the endpoint, or it may remain the endpoint.
Lightman tells FBI agent Reynolds his evaluation of Dillon was based on a feeling, not on science. When I have a strong feeling that someone is lying, and don’t know why I have that feeling, I regard it as an important data point, and if I have video I review it again and again. If I am doing the interview – and all to rarely do I get to ask the questions, instead having to put up with other people’s questioning – I will go back and question the interviewee repeatedly in different ways to try to find out what was the basis for my feeling. I would never submit a judgment that someone is lying based solely on a feeling, but then Dr. Lightman enjoys being cheeky, and I bet he is lying when he says that to get a reaction.