In our session “lessons from a consulting detective” presented in Sun Valley last March, Mark Duncan described several techniques that he relies on to sense if a suspect is a true sociopath. One of the inspirations for the session came from the dramatic approach used by Idris Elba in his portrayal of detective John Luther. In Mark’s talk we showed a clip from Luther where the detective determines that interviewee Alice Morgan is a sociopath based on her inability to produce an empathetic yawn. As it turns out, the results of a Baylor University psychology study indicate that people with psychopathic tendencies are indeed, less likely to be affected by “contagious yawning” than the general population. To see the specific Luther interview clip below start at the 19:10 mark. Keep watching as, Duncan follows up with several of his own tips, or you can dive in at the 21:18 mark.